Why shouldn't I be plugged into EHU all the time?

[aandncaravan]

Why shouldn't the Motorhome be plugged into EHU 240v all the time its out of use?

 

The battery charger does not turn off when the battery is full like most seem to think. The charger is Force Feeding battery all the time it is on EHU 230v. Not one of the battery chargers we have repaired shuts down totally.

They all continue to run up an electricity bill.

As well as wasting money, it's not very environmentally friendly.

 

Most do drop down into Trickle charge mode when the battery is full, but they continue to Force feed the battery, albeit at a low rate.

That clearly isn't ideal for either the battery or the charger.

 

Most chargers are designed with a 10 year life, at the average usage of around 60 days a years.

If you plug it in all the time, that is 6 years life used up in 12 months.

 

Our advice is watch the battery voltage, when they drop to about 12.7'ish volts, plug into EHU for about 24 - 36 hours, probably about every 5 - 6 weeks dependent on the devices you have consuming power. After a while you will get to know how regularly they need charge. It helps you keep in touch with their condition, if they start dropping down more quickly than normal something might be amiss.

 

If you like to run a heater unit inside the Motorhome in the Winter, find out where the mains Kettle lead goes into the charger and unplug it.

Sometimes the Charger is on an 'RCD' circuit separate from the 13a sockets you might use for the Heater. If so flick down (Off) the RCD switch that feeds the charger.

Don't switch off the Charger via any switches on the front of the box (like on a EBL99) as the switches have a habit of deteriorating and not powering back on. Most don't shut down the charger unit any way, just the 12v power distribution for lights, etc.

Only shut the system down via the control Panel above the door.

 

It is fine to leave the Charger running all the time you are using the Motorhome as the battery will get usage, but please let it rest when you park it up for a few weeks?

 

.

[chas]

An interesting post, I wonder if the same would apply for a fitted solar panel ?.

[Robinhood]

Given that I've questioned some of your assertions in another thread, I don't want it to appear that I'm stalking you, but as you have again postulated a number of theories that go against perceived wisdom set out elsewhere, and my own empirical experience, I am going to raise some questions about this as well.

 

 

aandncaravan - 2015-10-08 11:42 PM

 

Why shouldn't the Motorhome be plugged into EHU 240v all the time its out of use?

 

The battery charger does not turn off when the battery is full like most seem to think. The charger is Force Feeding battery all the time it is on EHU 230v. Not one of the battery chargers we have repaired shuts down totally.

They all continue to run up an electricity bill.

As well as wasting money, it's not very environmentally friendly.

 

Most do drop down into Trickle charge mode when the battery is full, but they continue to Force feed the battery, albeit at a low rate.

That clearly isn't ideal for either the battery or the charger.

 

 

I can't vouch for the units you've repaired, but CBE units in particular are advertised as having a zero charge phase at the end of the charging cycle, monitoring the battery until the voltage falls below a given level, and then restarting the charge cycle again. From experience I know this is the case, since I had a 'van delivered from new with a charger that would not restart after the zero charge phase, (unless it was physically switched off and on) even though voltage had dropped below the prescribed level. The replacement was monitored to prove that it did exactly that when permanently hooked-up; i.e. it dropped to zero for some time before restarting the charge cycle.

 

Most motorhome chargers fitted nowadays use an IUoU charging regime which will result in a final maintenance phase of between 13.5 and 13.8V (depending on settings) and a charge current which will rapidly (in this phase) drop to an absolute minimum (even if they don't completely shut off as above). I believe (though can't confirm) that Schaudt units will drop to this very low charge current at the end of the charge phase.

 

Given that, and assuming a (high) final maintenance charge current of 1amp, and a (low) efficiency of 80% for the charger, I make that an annual consumption of (1*13.8 * 24 *365)/0.8 Wh. i.e. at the worst case 15.1kWh per annum. At a cost of 11p per kWh, I'm not going to worry unduly about that (not least since there would also be a balancing cost of adopting the regime you recommend).

 

You also state "That clearly isn't ideal for either the battery or the charger.", but you provide no evidence for this - and it isn't clear (at least not to me). I can point to informed references that would aver the best way to keep a battery in condition is to ensure it has a permanent maintenance charge when not otherwise in use. As for the charger, my own experience of electronic equipment is that it is more likely to fail if it is constantly switched on and off, rather than left well alone.

 

 

aandncaravan - 2015-10-08 11:42 PM

 

Most chargers are designed with a 10 year life, at the average usage of around 60 days a years.

If you plug it in all the time, that is 6 years life used up in 12 months.

 

 

I'd certainly like to know your source for this, as I for one find it unbelievable!

 

My own experience is that my last two 'vans, each owned for approximately 5 years, have always been left on hook-up on the drive when not in use. I have (ignoring the original defective unit on one) had no problems at all with the chargers (which by your reckoning have exceeded their expected lifecycle by a factor of three!), and the batteries at the end of that period have shown no deleterious effects (indeed, they have appeared in better condition than those on previous vans disposed of at lower ages).

 

 

 

 

[Brock]

I decided not to keep charging my battery all the time the van was on the drive at the same time someone in our household decided to leave on a battery draining item. Battery was flat within two days. It never really recovered and had to be replaced.

[Guest pelmetman]

I only plug ours in a day or two before we're leaving, seems to work for us, our leisure batteries usually last 5 years + ;-) ............

 

 

[PJay]

pelmetman - 2015-10-09 5:57 PM

 

I only plug ours in a day or two before we're leaving, seems to work for us, our leisure batteries usually last 5 years + ;-) ............

 

Likewise. Plug in just to get the fridge cold, prior to going away.

PJay

[aandncaravan]

Robin Hood : I have no issue with being challenged, I don't consider myself to know everything (in fact my knowledge is scant) so happy to have an alternative view. However, I will try to answer the criticism as best I can.

 

The CBE chargers are not amongst our favourites, while we have opened several we have repaired none. The CB516, one of the more common CBE chargers, is cheaper to buy than repair.

 

The Schaudt, along with most modern chargers does drop down to a very low current. Exactly as we stated.

We wrote, "Most do drop down into Trickle charge mode when the battery is full, but they continue to Force feed the battery, albeit at a low rate".

 

Your calculation assumes that the 230v input draw is proportional to the output, this is not always so.

In anycase 15kw of electricity times 1 million people World wide each year is a heck of a lot of Greenhouse Gas. You may not be unduly worried by that, but I am.

 

As for not believing our assertion it is bad for the charger, we will present the very sophisticated Reich e-box 1 as an example.

 

On the Reich e-Box, it's 230v supply is dropped down by two quite large resistors to around 20v. The voltage is then refined and processed a lot more by the output stage before being applied to the battery. Those two resistors are constantly getting hot as a result of dropping the voltage all the time it is on EHU. Regardless of whether the 12/14v output stage is charging the battery or not.

 

Anyone who has opened an e-Box will confirm the two resistors almost always display signs of running warm. You can tell the units that stay on EHU for long periods because these resistors are fried.

 

I have just opened up a unit, photographed it then posted the pictures on the bottom of the websites Reich E-Box page, just for this thread. See : http://www.aandncaravanservices.co.uk/reich-e-box.php

 

The first photo shows the two resistors and the PCB at their base badly browned by the heat. The second photo gives a better shot of the resistors, quite clearly with all the markings burnt to almost unrecognisable. Yet this is a GOOD box, it's life was cut short, not from charger failure, but because Kristen from Sweden put a battery on the wrong way around and blew the controller/distribution electronics.

 

This charger unit has fan cooling to keep the 12/14v output side of the charger cool when it is working hard charging a battery. If the battery is 'full' with the charger in low power 'force feed' mode, the output stage of the charger will be cool so the fan will not operate.

However, the 230v input end of the charger is still processing 230v mains and the resistors still getting hot, but the fan will not operate no matter how hot they get.

The designers clearly expected the fan to keep the entire unit cool and prevent the resistors overheating.

Logic suggests that the designers thought the charger will only be employed to charge up a battery, that is it's job. When charging a battery the fan operates and the entire Charger stays cool. They presumably thought that their battery charger would not be used like they are.

 

It does not have a label saying '365 day trickle charger'.

 

Regardless of what folklore exists, it was designed as a battery charger that was to be turned off when it had done it's job.

 

And before you start to criticise the Reich design, it is one of the best. Very elegant, very efficient. It has, almost unique to Reich, a relay isolated output. The relay will isolate the charger output electronics from the battery if 230v mains is not available and/or the battery voltage is below 10v. A very clever and useful feature as it helps reduce the risk of a poor battery blowing the charger and any back feed discharging the battery.

 

While the actual electronics may be slightly different, almost all modern chargers have the same 230v drop to 20v input stage, with the sophistication in the 12/14v output charging stage.

 

For example, it is also obvious to us which Schaudt charger PCB's have been on EHU for extended periods.

 

Regardless of whether Robin Hood believes us or not, motorhome chargers are not designed as trickle chargers, but battery chargers.

 

Long term battery trickle chargers are specialist units, like the Optimate and Optimiser. They are not battery chargers (few 1 amp chargers can fully charge a big battery) but trickle chargers. Their output is SPECIFICALLY designed to be ultra low.

 

 

As for the source of our view on charger lifetime? It is experience based on seeing lots of them from almost all manufacturers from around the World.

 

 

As for evidence that continually force feeding a battery is not good for it, I would turn that around and ask you to show me Battery Manufacturer advice that says it is good to permanently charge a battery for 5 years on a battery Charger?

 

 

My favourite, rather silly, analogy is that you would not shut your Dog in the corner of the kitchen and continually 'Force Feed' it without any exercise.

Dogs like a little bit of food and a little bit of exercise. Please think of your battery like that and help save the planet?

 

 

 

 

 

 

 

 

[Robinhood]

aandncaravan - 2015-10-09 8:20 PM

 

Robin Hood : I have no issue with being challenged, I don't consider myself to know everything (in fact my knowledge is scant) so happy to have an alternative view. However, I will try to answer the criticism as best I can.

 

 

I'd prefer the term critique, criticism sounds so much more negative ;-).

 

I too don't consider myself to know everything (indeed, if I needed my motorhome electronics repairing I probably wouldn't know where to start. Maybe I'd have to contact yourselves (but now keep quiet about my nom-de-plume :-))).

 

Where I don't feel I know enough about a subject of specific interest, however, I do like to "dig underneath" the various points of view, particularly where they are at odds with my own experience or current practice, or well-established views expressed (and scientifically supported) elsewhere.

 

I've read a number of your posts with interest; agree with some of your views; have learnt some things without necessarily agreeing fully with your conclusions (the discussion on charging of AGM batteries was interesting - I'd still dispute some of the practical detail - though Schaudt now having announced a charger with a third (AGM) charging regime selectable adds a little more weight to your views!).

 

On the other hand, there also seems to me at least to be a liberal sprinkling of "FUD" in some of your posts which leads me to question some of your final conclusions (particularly when looked at in context). Hence my "critique" of a couple of recent posts.

 

I have to say, whilst I don't really like disassembling long posts, I'm prone to doing so with those of the nature you've just made. So, to paraphrase 'Allo 'Allo, I shall try to do this only once, to illustrate my points and then leave anyone who reads it (will anyone bother?) to form their own opinion.

 

aandncaravan - 2015-10-09 8:20 PM

 

The CBE chargers are not amongst our favourites, while we have opened several we have repaired none. The CB516, one of the more common CBE chargers, is cheaper to buy than repair.

 

 

I simply introduced the CBE chargers as an example of such that I know does suspend charging at intervals whilst being left permanently on. I note you don't comment on this.

 

My experience of them (other than the one that was "duff" from the off) in 10 years of use has been good, and I like their neat footprint and functionality.

 

As you are a repairer of such items, the fact that they are cheaper to replace than repair may be a factor in your view? ;-).

 

aandncaravan - 2015-10-09 8:20 PM

 

The Schaudt, along with most modern chargers does drop down to a very low current. Exactly as we stated.

We wrote, "Most do drop down into Trickle charge mode when the battery is full, but they continue to Force feed the battery, albeit at a low rate".

 

Your calculation assumes that the 230v input draw is proportional to the output, this is not always so. In any case 15kw of electricity times 1 million people World wide each year is a heck of a lot of Greenhouse Gas. You may not be unduly worried by that, but I am.

 

 

AIUI, there is a subtle difference between a "trickle" charge and a "float" charge, they aren't synonymous, and I'm not clear you're using the appropriate term in every case. (throughout the text you often appear to use "trickle" where I think "float" would be more appropriate - but I may be wrong, as I can also find such inconsistencies elsewhere for other well-advised sources!).

 

Also AIUI, to be defined as an IUoU charger, as most reasonably modern motorhome chargers are, the final charge stage should be "float" rather than "trickle" (though, patently, I can't vouch for the actual implementation on individual makes that claim to be IUoU ).

 

A float charge is designed (at optimum) to replace the self-discharge of a battery, and also to be suitable for long term use in maintaining that battery, by reducing gradually the charge to a minimal level, or indeed, periodically removing the charge. For a battery/charger combination in such a state, I think using terminology such as "force feeding" is rather misleading.

 

You did indeed indicate that the charger would drop to a low rate, but IMO rather overplayed the cost implications of permanent charge. I would think that the 230v input draw will absolutely be proportional to the output, just not linearly so across the output range. (Schaudt actually quote an efficiency of 90%, CBE slightly less; As I'd expect efficiency to drop the lower the output, I've underplayed this at the low "float charge" level, but I suspect I've also overplayed the 1amp average float charge).

 

If you're worried about greenhouse gases, then I'll give you half of the argument (since even your recommended charging regime would net some of that off), but frankly, such emissions pale into insignificance against other effects of the motorhoming pastime (the real annual consumption equating to less than many motorhome's single-evening heating consumption).

 

aandncaravan - 2015-10-09 8:20 PM

 

As for not believing our assertion it is bad for the charger, we will present the very sophisticated Reich e-box 1 as an example.

 

On the Reich e-Box, it's 230v supply is dropped down by two quite large resistors to around 20v. The voltage is then refined and processed a lot more by the output stage before being applied to the battery. Those two resistors are constantly getting hot as a result of dropping the voltage all the time it is on EHU. Regardless of whether the 12/14v output stage is charging the battery or not.

 

Anyone who has opened an e-Box will confirm the two resistors almost always display signs of running warm. You can tell the units that stay on EHU for long periods because these resistors are fried.

 

I have just opened up a unit, photographed it then posted the pictures on the bottom of the websites Reich E-Box page, just for this thread. See : http://www.aandncaravanservices.co.uk/reich-e-box.php

 

The first photo shows the two resistors and the PCB at their base badly browned by the heat. The second photo gives a better shot of the resistors, quite clearly with all the markings burnt to almost unrecognisable. Yet this is a GOOD box, it's life was cut short, not from charger failure, but because Kristen from Sweden put a battery on the wrong way around and blew the controller/distribution electronics.

 

 

So, not an example of one that has failed by being used "365 days a year" (see later), but one that has failed through (other, if you must see it as that) misuse?

 

I would also point out that on the same page you quote "We have seen few Reich e-Box equipped Burstners with a Habitation Battery bank less than 200Ah so it is not surprising so many e-Box units buckle under the load. I wouldn't argue with the widely accepted point of view that the maximum load should be matched to the charger capacity, so there may be a more obvious reason for some of the (failed) chargers that you repair?

 

aandncaravan - 2015-10-09 8:20 PM

 

This charger unit has fan cooling to keep the 12/14v output side of the charger cool when it is working hard charging a battery. If the battery is 'full' with the charger in low power 'force feed' mode, the output stage of the charger will be cool so the fan will not operate.

However, the 230v input end of the charger is still processing 230v mains and the resistors still getting hot, but the fan will not operate no matter how hot they get.

 

The designers clearly expected the fan to keep the entire unit cool and prevent the resistors overheating.

Logic suggests that the designers thought the charger will only be employed to charge up a battery, that is it's job. When charging a battery the fan operates and the entire Charger stays cool. They presumably thought that their battery charger would not be used like they are.

 

 

Your logic might suggest this - I can't see anything that makes me think so.

 

I readily admit, I'm not at all familiar with the Reich equipment, and don't know what the design criteria and charging regime are. I can see that their info for these boxes includes the words "The thermally controlled fan can be switched-off completely, at choice", which rather leads me to believe that (regardless of any issues you may have observed) the designers were entirely happy for the box to be running without fan assistance. (and I readily accept that designers sometimes get it wrong, but not usually for long if they are to keep their job).

 

aandncaravan - 2015-10-09 8:20 PM

 

It does not have a label saying '365 day trickle charger'.

 

 

Now we're descending into rather silly argument. :-(

 

I'm inclined to leave it at that, but, since you raised it as part of your background.....

 

....I wouldn't expect it to, but neither does it have a label (or instructions), that say "not a 365 day trickle charger" or "only use for an average of 60 days a year", which surely would be more relevant in a charger that the manufacturer is going to warranty for two or three years, but would, in your estimation, exceed its design criterion in that period if used in such a manner.

 

And, in any case, the 365 days is thoroughly disingenuous. People tend to use their motorcaravans (admittedly, some more than others). My current 'van has been in active use (i.e. not on maintenance charging on the drive) for about 50% of its life so far (sometimes on hook-up, and sometimes not).

 

aandncaravan - 2015-10-09 8:20 PM

 

Regardless of what folklore exists, it was designed as a battery charger that was to be turned off when it had done it's job.

 

 

...in your opinion? Can you quote me a manufacturer that explicitly says so? (and indeed, what is its job, since most of them are quoted as delivering a float or maintenance charge as the last part of their cycle).

 

aandncaravan - 2015-10-09 8:20 PM

 

And before you start to criticise the Reich design, it is one of the best.

 

 

I wouldn't attempt to do so, for far more reasons than my unfamiliarity outlined above, but also because I don't think it's introduction is very relevant to my questioning. (though you do seem to have started criticising it yourself ;-))

 

aandncaravan - 2015-10-09 8:20 PM

 

Very elegant, very efficient. It has, almost unique to Reich, a relay isolated output. The relay will isolate the charger output electronics from the battery if 230v mains is not available and/or the battery voltage is below 10v. A very clever and useful feature as it helps reduce the risk of a poor battery blowing the charger and any back feed discharging the battery.

 

While the actual electronics may be slightly different, almost all modern chargers have the same 230v drop to 20v input stage, with the sophistication in the 12/14v output charging stage.

 

For example, it is also obvious to us which Schaudt charger PCB's have been on EHU for extended periods.

 

Regardless of whether Robin Hood believes us or not, motorhome chargers are not designed as trickle chargers, but battery chargers.

 

 

I'll overlook this last sentence as a rather condescending statement ;-)

 

aandncaravan - 2015-10-09 8:20 PM

 

Long term battery trickle chargers are specialist units, like the Optimate and Optimiser. They are not battery chargers (few 1 amp chargers can fully charge a big battery) but trickle chargers. Their output is SPECIFICALLY designed to be ultra low.

 

 

As for the source of our view on charger lifetime? It is experience based on seeing lots of them from almost all manufacturers from around the World.

 

 

But to be clear; I didn't ask for the source of your view on charger lifetime, I asked for your source for the statement that "Most chargers are designed with a 10 year life, at the average usage of around 60 days a years" which is an entirely different and very specific statement that I would be very surprised that any manufacturer would endorse. I still find it hard to believe.

 

If instead, you had stated that, "in our experience, the chargers we repair have suffered failure at an average of 600 days use" or some such similar or equivalent statement, then I would have had difficulty contesting it.

 

What would, however, still be statistically questionable is whether one can extrapolate such a view from a sample of mainly-failed units with a dubious history of usage or installation (much of which is detailed on your own website), to cover the hundreds of thousands of installed units that (presumably) have happily performed for years without a glitch.

 

But, if you had gone even further and the statement had been something along the lines of :

 

"In our experience, the chargers we repair have suffered failure at an average of 600 days use. As part of our examination and repair process, we have come to the conclusion that one factor in such failure may be the use of the charger on hook-up but without use for extended periods. You may wish to be aware of this, and if necessary adjust your use

 

....It would have been decent food for thought, and I wouldn't have chosen to comment at all.

 

There was just so much more "embroidery" around this that need(s)(ed) questioning.

 

aandncaravan - 2015-10-09 8:20 PM

 

As for evidence that continually force feeding a battery is not good for it, I would turn that around and ask you to show me Battery Manufacturer advice that says it is good to permanently charge a battery for 5 years on a battery Charger?

 

 

...and we descend yet again into rather silly argument.

 

I wouldn't expect to be able to reference such a statement, and to be specific, we're actually talking about keeping a battery in condition under a float or maintenance charge for a period whilst not being otherwise used.

 

It is very easy to find reference to best practice for the latter, web searches will throw up numerous hits; My own historical experience includes implementation of massive banks of lead-acid batteries to provide UPS capabilities to large Datacentres. The number of the batteries involved rendered it critical to eke the optimum life out of them as the cost of replacement was high. They were permanently under maintenance (float) charge for years, apart from periodic testing of the UPS, under a regime fully-endorsed by the manufacturer (from whom they were always bought direct) as best practice.

 

There are manufacturers who endorse maintenance charging of batteries (including the types used as leisure batteries) in long-term storage, Exide being one of them.

 

And, picking up the point made by another poster above, most people with solar panels installed will be charging their batteries 365 days a year, and again I'm not aware of the majority of these complaining that it has had a deleterious effect on battery life (though, of course, it's unlikely to be 24/365 ;-).

 

aandncaravan - 2015-10-09 8:20 PM

 

My favourite, rather silly, analogy is that you would not shut your Dog in the corner of the kitchen and continually 'Force Feed' it without any exercise.

Dogs like a little bit of food and a little bit of exercise. Please think of your battery like that and help save the planet?

 

 

Indeed, a rather silly, and quite inappropriate, analogy. ;-)

 

==============

 

But, to summarise:

 

1 Based on both experience and widespread technical input, given a roughly appropriate charging regime I'm not concerned about the practical effect on leisure batteries of being on charge on the drive between use

 

2 There is an interesting question as to whether the regime produced by all chargers is "roughly appropriate" as above (experience of CBE chargers with both lead-acid and gel batteries would lead me to believe that they at least are OK - or maybe I've just been lucky. Other chargers may not exhibit the same properties).

 

3 I acknowledge your input on the chargers you have seen, and see it as valuable, raising the question of whether such chargers are "man enough" for permanent use, but as above, I have concerns about whether a limited sample consisting largely of failed units of dubious history can be extrapolated to a much larger (and assumed trouble-free) population.

 

People will no doubt make their own mind up, swayed or not by the various core arguments.

 

Much of the rest is (IMO) simply "embroidery".

 

(and from the length of the post, I fear I may be morphing into one BK, so this will be the end of it) :-)

 

 

 

 

 

[Rayjsj]

This Conflict of opinions has intrigued me, as I DO leave my van connected into EHU , and the charger working all through the winter, mainly to have a Small oiled filled radiator on a timer, to stop the Soft furnishings from getting damp. But also to keep the batteries topped up, (2x 110ah).

So much so, that I have e-mailed Sargent, the makers of my Electrics and charger for their advice.

I'll let you know what they say, if they answer.

[aandncaravan]

I too have a background of working in Datacentres requiring standby power from huge banks of batteries. I have one particular unpleasant memory of helping the engineer to change them one time.

They were replaced every 8 years even though they were hardly ever used.

 

When I was asked to put on an acid resistant overall and gloves, I thought it was just a unnecessary precaution.

I could not believe the state of some of the batteries that were removed.

When I questioned if there was something wrong because there were so many failed batteries, he said that's how they always are.

 

These were specialist, ultra long life, hugely expensive, Yuasa batteries being replaced prior to the battery manufacturers recommendations.

 

So your experience that being permanently on charge is good for a battery does not match mine.

 

.

[Robinhood]

Rayjsj - 2015-10-10 1:53 PM

 

So much so, that I have e-mailed Sargent, the makers of my Electrics and charger for their advice.

I'll let you know what they say, if they answer.

 

...I know for a fact that the documentation for some (possibly all) of the current Sargent units specifically endorses "continuous" operation.

 

....though, of course, that might be open to interpretation. ;-)

[Robinhood]

aandncaravan - 2015-10-10 2:24 PM

 

So your experience that being permanently on charge is good for a battery does not match mine.

 

.

 

....must admit, we never tried to squeeze 8 years out of hours, and we did have very good quality maintenance chargers.

 

Though, when disposed of at the end of their "risk" life, they were generally seized on by various parties who tendered to take them away and re-use them in less-critical applications.

 

edit typo

[aandncaravan]

Sorry one other thought about your Datacentre experience I assume the batteries were replaced regularly like the ones were I worked in my time, at the Alliance and Leicester, HSBC Bank, Lloyds Bank, Hambros Bank, Kent County Council, Merseyside Council, etc?

Or did the fact they were rarely used but permanently on charge mean they lasted for ever?

You write, " I can point to informed references that would aver the best way to keep a battery in condition is to ensure it has a permanent maintenance charge when not otherwise in use".

 

If leaving a battery on permanent charge is better for it and conditions it, why do Datacentre UPS batteries every need replacing?

 

When a lower cost Motorhome battery can last 10 years (according to Stuart0's experience) shouldn't a battery that is designed to be permanently on charge last longer still, especially as the only time they normally get used is for those few minutes between the mains supply being cut and the Standby Generator picking up the load?

 

 

You question the use of the fan in the Reich e-box I we use as an example, saying it can be powered off by the user.

It can't.

But it can on the e-Box II, which is a completely different unit. If you choose to power of the fan on the e-Box II it drops into a lower power mode.

 

 

You also question our Charger lifetime of 10years and write

 

"My own experience is that my last two 'vans, each owned for approximately 5 years, have always been left on hook-up on the drive when not in use. I have had no problems at all with the chargers (which by your reckoning have exceeded their expected lifecycle by a factor of three!),

In other words you insinuate the van has been hooked up permanently for 5 years and has had a 30 year 'life'?

 

Yet in the next post you write, "My current 'van has been in active use (i.e. not on maintenance charging on the drive) for about 50% of its life so far (sometimes on hook-up, and sometimes not)".

From your other posts on the Forum I had got the impression that when in "active use", you tended to be off EHU?

Doesn't that paint a different picture, not exceeded the charger lifetime by a 'Factor of 3', but half that?

 

Doesn't that also mean that your batteries spent 50% of their time without being 'Force Fed' and could that be the reason they have survived as well as they have?

 

 

 

[aandncaravan]

My Television can be used continuously too!!.

 

Could there be a 'common sense' factor that the manufacturers thought should be considered?

 

 

[Robinhood]

In addition to getting well away from the original topic, I think were largely getting into ping-pong here. I've made most of my points, but I'll answer this last set of questions (which I don't think move the debate forward much) and then that's it.

 

 

aandncaravan - 2015-10-10 3:59 PM

 

Sorry one other thought about your Datacentre experience I assume the batteries were replaced regularly like the ones were I worked in my time, at the Alliance and Leicester, HSBC Bank, Lloyds Bank, Hambros Bank, Kent County Council, Merseyside Council, etc?

Or did the fact they were rarely used but permanently on charge mean they lasted for ever?

You write, " I can point to informed references that would aver the best way to keep a battery in condition is to ensure it has a permanent maintenance charge when not otherwise in use".

 

If leaving a battery on permanent charge is better for it and conditions it, why do Datacentre UPS batteries every need replacing?

 

 

We used to aim for 5 years (though I believe that was extended somewhat "after my time"). As I've said, they were then removed under tender and further (though less-critical) use made of them.

 

As for the remainder, I think you're asking the wrong question. Batteries have a finite life (The conditions of use affect this, as do other factors such as the manufactured quality of a single battery).

 

The charging regime used is not designed to give the battery infinite life (even the best can't) it is simply designed to get the best operational life (under the installed conditions). To this end, a continuous float charge was used (as widely acknowledged as the best method, and recommended by the supplier/manufacturer). TBH, I'm surprised you've asked the question since you imply that the installations you've worked in did exactly the same under the same conditions, and I bet no-one suggested just charging for a short interval once a week!

 

As you like dog analogies, A dog fed on a healthy diet is likely to live longer than one that isn't, but however healthy the diet, it ain't going to live for ever. ;-)

 

aandncaravan - 2015-10-10 3:59 PM

 

When a lower cost Motorhome battery can last 10 years (according to Stuart0's experience) shouldn't a battery that is designed to be permanently on charge last longer still, especially as the only time they normally get used is for those few minutes between the mains supply being cut and the Standby Generator picking up the load?

 

 

But I don't know how Stuart has used his battery, maybe he's just been lucky (or maybe he's had it permanently on charge :-) )

 

In reality, there will be "outliers" to the "normal" life in datacentre batteries - some might well be going strong at 10 years or more; the problem is you wouldn't know the ultimate life until it started dying, (actually, in a UPS installation probably not until it was dead) and that's too late to risk - it's not quite the same for a motorhome battery.

 

aandncaravan - 2015-10-10 3:59 PM

 

You question the use of the fan in the Reich e-box I we use as an example, saying it can be powered off by the user.

It can't.

But it can on the e-Box II, which is a completely different unit. If you choose to power of the fan on the e-Box II it drops into a lower power mode.

 

 

..well, I did say I wasn't au fait with Reich equipment - I bow to your superior knowledge.

 

 

aandncaravan - 2015-10-10 3:59 PM

 

You also question our Charger lifetime of 10years and write

 

"My own experience is that my last two 'vans, each owned for approximately 5 years, have always been left on hook-up on the drive when not in use. I have had no problems at all with the chargers (which by your reckoning have exceeded their expected lifecycle by a factor of three!),

In other words you insinuate the van has been hooked up permanently for 5 years and has had a 30 year 'life'?

 

Yet in the next post you write, "My current 'van has been in active use (i.e. not on maintenance charging on the drive) for about 50% of its life so far (sometimes on hook-up, and sometimes not)".

From your other posts on the Forum I had got the impression that when in "active use", you tended to be off EHU?

Doesn't that paint a different picture, not exceeded the charger lifetime by a 'Factor of 3', but half that?

 

Doesn't that also mean that your batteries spent 50% of their time without being 'Force Fed' and could that be the reason they have survived as well as they have?

 

 

Well, no, I'll restate again. What I questioned is your assertion that the design criteria for these chargers was 10 years at an average use of 60 days a year.

 

...and sorry, the last two 'vans have been hooked up for the portion of their life they've spent on the drive, and also the majority of their time whilst in use.There has been a small proportion of off-grid use, but most Aire/Stellplatzes we've used we've availed ourselves of electric.

 

Family changes and the fact I have refillable gas in the current 'van mean there will be more times when we're off-grid since May this year, but even then not to the extent you've conjectured.

 

 

[Tracker]

I suspect that the ideal is somewhere between the two extremes?

 

Could it be that just as always on charge might damage a battery so might always off charge.

 

This is especially true given the built in ability of the on board electronics, never mind the added burden of an alarm or tracker, to discharge the battery if left unattened for more than a few weeks.

 

For my own part I never use hook up, but do try to either take the van out or at least run up the engine for 15 minutes or so once a month over the winter.

 

Failing that I use a Ctek charger overnight on both starter and leisure batteries once a month - but not simultaneously!

 

I prefer to keep it simple!

[kevina]

I'm a bit of a Victron fan and this is an extract from their "Energy Unlimited" publication. It's written with yachts in mind but in this conclusion of "How should a battery be charged" there is a direct parallel with motorhome leisure batteries.

 

*

1) Cyclic use, in the partial state of charge mode, when sailing or at anchor. Important here is charging as fast as the battery permits. Temperature compensation is a must to prevent early failure due to overheating and excessive gassing.

 

2) A mixture between float use and short, shallow discharges when motoring or moored. The risk here is that a 3-step alternator regulator (when motoring) or a charger, (when connected to shore power) is frequently triggered by these shallow discharges to go into bulk and then absorption mode. The result could be that the battery is continually subjected to absorption charging and will be overcharged. Therefore, ideally, the length of the absorption phase should be in accordance with the preceding DoD. See section 5.3.2. for the adaptive charging method, a Victron Energy innovation.

Flooded batteries, if being float charged without any discharge occurring, should be switched to the lower 2.17 V per cell level and be regularly topped up with an absorption charge at 2.4 V / cell or more. Again, see section 5.3.2.

 

3) For long periods of time the battery is left open circuited or float charged, in wintertime for example.

As discussed in sect. 4.2.3, most flooded batteries will deteriorate quickly if float charged at 2.3 V per cell for a long time. Ideally charge voltage should be lowered to between 2.15 V and 2.2 V per cell, or left open circuited and recharged regularly. When the average temperature is 20°C or less, at least every 4 months. At higher temperatures they should be recharged more often.

 

From my (Victron authors) personal experience and from numerous discussions with boat owners, I do also prefer to leave sealed Exide/Sonnenschein Dryfit A200 batteries (Gel) or equivalent open circuited or on a lower than recommended float level instead of float charging them at 13.8 V, because, although in theory they can be float charged during long periods of time, only too often the result was damage due to overcharging. (in fact Victrons own chargers now have a 13.2v long term storage stage [Kev])

 

*

I leave my solar panel disconnected except whilst living in the van. I don't leave my leisure batteries on charge as they are gel and would last 6 months but do give them a top up once a month or so. The vehicle battery gets a fortnightly charge from a separate ctek charger.

 

I used to leave my (original fit) Banner Energy Bull batteries on mains and solar charge but they didn't last as long as expected so have a new regime with the gels. I think their early loss of capacity was more due to heavyish use and the fact that my solar charger never drops to a float charge (to do with para 2 above) than the due to the CBE charger.

 

Kev

[aandncaravan]

Thank you, we also rate the Victron Energy products

 

The publication in the above thread says,

".. most flooded batteries will deteriorate quickly if float charged at 2.3 V per cell (13.8v per battery) for a long time. Ideally charge voltage should be lowered to between 2.15 V (13.02v) and 2.2 V per cell(13.2v per battery), or left open circuited and recharged regularly".

 

The lowest maintenance charge we have seen from any Motorhome or Caravan charger on a wet setting is 13.5v, generally 13.8v, which as stated above by Victron Energy, can cause damage.

 

The document goes on to say "also prefer to leave sealed Exide/Sonnenschein Dryfit A200 batteries (Gel) or equivalent open circuited or on a lower than recommended float level instead of float charging them at 13.8 V".

 

This potential damage to the battery is in addition to the wear on the charger and the unnecessary waste of electricity.

 

 

So returning to original post we advise not leaving the MH on EHU for long periods of time, such as in storage.

 

Why is it always so hard to try and give out advice intended to help?

 

 

 

[Robinhood]

aandncaravan - 2015-10-10 7:37 PM

 

Why is it always so hard to try and give out advice intended to help?

 

 

...maybe it's a style thing Allan. (lol)

 

(as I've stated above, if you'd put your message across differently, I wouldn't have felt inclined to respond).

 

Nonetheless, it has sparked some interesting debate, some of which I agree with, some of which I still don't, and some of which, since there are conflicting views or insufficient/unsafe evidence, the jury (or at least mine) is still out.

 

Having made your point, I've little doubt the post will have served its purposes, and also given pause for thought. People, will no doubt make their own judgement and react accordingly, and indeed, discussion on these forums, even if somewhat "animated", should always be targeted on aiding that process.

 

+++

 

Now, since you've gleefully seized on the extract from the above "Victron" publication as it appears to support your argument, let me point you to the full contents of Section 4.2.3 (the detailed one on Float Charging) in the self-same document and referenced in Kevina's original post.

 

Regarding float voltage we must distinguish between flooded and VLRA batteries:

....

2) All VLRA batteries mentioned can be float charged for long periods of time, although some studies have shown that a treatment similar to the one proposed here for flooded batteries will increase service life (see for example “Batterie Technik” by Heinz Wenzl, Expert Verlag, 1999).

 

....which is about all it says on such batteries.

 

Guess the technology of the ones I use? B-)

 

Seconds out.....round 2!

 

(Seriously, no - I've posted the above simply to illustrate the issues of selectively quoting out of full context to support one's views (or seizing on the same). I have little doubt that, since I might be seen as just having done the same, a trawl of the web could easily find contradictory advice to the above, possibly even in the self-same document, and we could go on for ever).

 

Your advice has been successfully delivered, it can be absorbed by its audience, and we can call it a day.

 

;-)

[aandncaravan]

Robin Hood, I am sorry but the Gloves are off now................ (lol)

 

Thank you, I do enjoy sparring with you because you fight fair and put up really good alternative argument. That can only be good for everyone.

 

I accept your point about taking extracts in isolation, valid point. But it is so hard not to do!

 

Till the next Post?

 

 

 

:D

[Robinhood]

Following the debate above, I was talking to a friend with a Bürstner who confirmed he'd had problems with the electronics.

 

He's had to have them replaced a couple of times, but now he's on his third Reich e-Box, he's expecting this one to last a thousand years.

.

.

.

.

.

.

.

.

 

I'll get my coat. ;-)

[Tracker]

Robinhood - 2015-10-11 7:26 PM

He's had to have them replaced a couple of times, but now he's on his third Reich e-Box, he's expecting this one to last a thousand years.

.

 

Let's hope his lasts even as long as the last bloke that tried that caper, let alone 1000 years!

[aandncaravan]

In case anyone does need a device to maintain their batteries in long term storage, the Optimate is a specialist device : http://www.optimate.co.uk/optimate%202.htm

It does not charge continuously. It has periods of charge followed by being idle.

It only spends 50% of it's time charging.

It's voltage is also lower than the average Motorhome 'Float' charger, at 13.6v, and it has a very low charger current which is a maximum of just 0.8A.

 

This combination of lower voltage, lower current plus 50% idle time is likely to have a less detrimental impact on long term battery 'maintenance'.

 

We don't recommend the use of the Optimate, we think the best option is to charge fully every few weeks as stated earlier, but this is a potential option for those who need it.

 

 

 

[StuartO]

I'm taking a break from contributing but I do read the forum sometimes and since my long-lasting batteries got a mention in this discussion, which has been interesting, I thought I would spell out the details.

 

I've had the MH from new (in early 2006) and it came with a pair of Exide G80 gel leisure batteries. It has a Schaudt EBL 101 electroblock, which handles all the electrics. Until recently it lived in a garage, plugged into the mains and had relatively light use, mostly on sites with an EHU. Solar panels (with a Schaudt regulator) were added about 5 years ago but in the garage of course they contribute nothing.

 

I did worry about continuous 240v and contemplated using an intermittent mains supply using a timer but then read about the way the Electroblok applies a terminal 14.4 volt charge to gel batteries and felt that leaving the mains on continuously would avoid repeating this phase endlessly, which might do some harm. So the MH simply stayed connected to the mains.

 

The batteries are still doing OK and no reason has materialised to change them yet, despite me looking for such. When we are using the MH off EHU the batteries stand up to using lights and TV etc and the Schaudt display shows only a proportionate discharge level by morning. The batteries are not at least ten years old so they cannot last much longer and maybe it's time to replace them anyway, but leaving them on continuous EHU certainly doesn't appear to have done them any harm. The engine battery was replaced last year when it was found dead one morning after a night off EHU on an Aire. That was 8 years old so no complaints and it seemed to die because of a cell failure; it was whatever Fiat supplied with the vehicle and I replaced it with another good quality engine battery.

 

The MH is currently stored outside, without EHU, but the solar panels seem to be keeping both leisure and engine batteries charged. The controller feeds the batteries with 14.3 volts when the panels are active and that seems to be the "float" level rather than 13.8/9, when on EHU. No idea whether that will be disadvantageous in the long term.

 

Having read this discussion with interest I think that the various charger/controller outfits in different MHs, not to mention the different types and sizes of batteries, are likely to behave quite differently so that some will cope well with long term EHU connection in storage and some won't. I'm not convinced by suggestions that chargers and controllers will get overloaded or worn out in service if they are well designed and operate within their design limits, but maybe time will prove me wrong. I've developed confidence thet my Schaudt system with Exide gel batteries works reliably and well and can cope with being continuously hooked up no problem.

 

The decision I face is which leisure batteries to buy when I replace the Exide G80 gels, which I'm bound to need to do soon so I'll probably do this winter or next spring. I could buy cheaper and perfectly suitable batteries, such as the Bosch S5, but over ten years the extra cost of my Exide gels will hardly be significant and that's what Hymer/Schaudt designed my MH to use, so 'll probably stick with them. I'll probably put the MH back onto continuous mains supply once it's parked at home again too.

[bimbo]

With all respect, but you live in the uk ? solar panels only charge when there is sun .