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

[aandncaravan]

Stuart, there is credible evidence here from battery manufacturers and experienced, skilled professionals. Even from Charger manufacturers, building new units with reduced charger voltages.

 

You are advising people to ignore that based on just your own limited experience with one Charger and battery?

 

You write, "If your MH has a decent charger, leave it plugged in if you like and the floating voltage shouldn't do much harm, even if it is 13.8v. If you have solar panels and your MH is stored outside, even if you are in UK, you will get something like 14.3 volts from them but only for part of the day so that shouldn't do much harm either".

 

 

Our advice to look at how long term EHU is used has no adverse consequences. What if you are wrong?

 

 

 

 

 

[Rayjsj]

Rayjsj - 2015-10-14 10:01 AM

 

Had my reply from Sargent regarding leaving EHU and charger charging all the time. They say that their chargers are designed to be constantly connected to mains electricity, and will keep both vehicle and leisure batteries in a fully charged state, without overcharging or damaging them or the charger, also there are 'failsafe' systems to protect both batteries and charger should a fault occur.

Sounds good enough for me, so, I will carry on leaving the charger on all the time. Ray.

 

Thought I would rejoin this discussion with my recent findings. About a month ago we were getting ready to go away and i could smell rotten eggs from my battery compartment, checked both Banner Energy Bull 110ah batteries, one was VERY hot, so much so that the case was deforming (bulging) ! Quickly removed the fuse, and checked the fluid levels, Yes, it was nearly dry, took 3 litres of de-ionised water to bring the level back, the 2nd Banner was low, but only needed 1 litre to restore the level. Luckily both batteries had breather pipes connected and the gassed off fluid went safely outside the motorhome. Re-connected dry battery and turned on charger, after a short time the same battery started gassing off again and getting warm. When checked, it wasnt holding a charge. It was dead ! At just 2 years old. The 2nd Banner is still ok and holding a charge. The Sargent charger appears to be ok and is not overcharging ?

Good news is, I bought the battery from Alpha Batteries who give a 4 year warranty, I paid by Pay Pal so was able to E-mail them the original sales invoice, and they have sent me a new Banner Battery.

CONCLUSION. I will no longer leave my Batteries constantly on EHU charger on maintenance charge,

I have a 100watt solar panel which will hopefully keep them ticking over ? If not i will give them a boost with the charger every 6 weeks or so.

Banner Batteries sales blurb says they are Maintenance Free, when quite obviously they are not. They even sell a special tool for removing the cell caps !! Whatever, i will be checking the fluid levels regularly from now on. At least every 6 weeks. Wish I had listened to experienced advice rather than the charger manufacturer.

[StuartO]

aandncaravan - 2016-10-05 2:20 PMStuart, there is credible evidence here from battery manufacturers and experienced, skilled professionals. Even from Charger manufacturers, building new units with reduced charger voltages.You are advising people to ignore that based on just your own limited experience with one Charger and battery? You write, "If your MH has a decent charger, leave it plugged in if you like and the floating voltage shouldn't do much harm, even if it is 13.8v. If you have solar panels and your MH is stored outside, even if you are in UK, you will get something like 14.3 volts from them but only for part of the day so that shouldn't do much harm either".Our advice to look at how long term EHU is used has no adverse consequences. What if you are wrong?

 

My current conclusion is based on there being no compelling evidence of serious adverse effect from 13.8 volts as a float voltage, used widely over many years with many types of batteries, and merely an indication that 13.5 might be better, so newer equipment is being optimised slightly differently.

 

I might be wrong and 13.5 volts might in due course prove to be much better but how better is much?  And how bad would be the consequences be of sticking to the old ways anyway, if you already have equipment which works well enough? 

 

There are lots (and lots) of variables in the equation, not least the individual user's widely varying pattern of use of motorhomes so I say don't jump to the conclusion that this new view (that 13.5 is better than 13.8) turns the whole apple cart over.

 

If I was having to replace my equipment now I might well go for something incorporating the latest ideas but if it ain't broke, why keep trying to mend it?

 

[aandncaravan]

My point was that you are actually advising people to ignore an expert company like Victron Energy who say long term float at 13.0v - 13.2v is the ideal. You say carry on with up to 14.2v.

 

You are not saying it is what you would do, but actually advising people to ignore the experts.

If thousands follow your advice and end up with duff batteries that then kill the charger units, that would be pretty disappointing consequences for them. Especially if it is a £600+ e-Box that blows up.

 

On another recent post of Solar vs Generator you state that charging up a battery using a Schaudt charger takes forever. When it doesn't, they are one of the fastest for their size.

You have previously stated you had two Gel batteries that were 10 years old. Gel batteries take longer to charge, but when a Gel battery ages it will take even longer to charge.

A battery bank of 160Ah 10 year old Gels on a Schaudt 18A charger WILL take forever to charge and that was maybe what you experienced. Leading me to suggest that your two gels were past it years ago?

 

Gel batteries in such a state may tend to absorb a higher float charge, to overcome all the internal corrosion and degradation, so that a higher Float for such batteries may actually be required, without any adverse effects.

The impact on a modern quality battery that doesn't self discharge, unlike those 6 years ago, might be totally different?

And that is another point, that things change. Even if your experiences of 8 years ago were relevant then, doesn't mean they are now with all modern battery types.

Batteries have advanced so much in the last few years, that what was necessary to maintain them back then may not be appropriate now. We think the big battery manufacturers have been slow to take this on board, but are now.

 

The reason Victron Energy have been the first is because they make batteries and Chargers. Not just badge other companies chargers, but have a charger R & D facility. They are one of the most Technically advanced battery/charger companies out there, because they do both so well.

 

So while 13.8v long term EHU may have worked for you and the old Gel's, it is a small pool of experience. Even if the thinking/experience was appropriate 7 years ago, doesn't mean it is now.

 

 

It doesn't seem to me to be the best background to actually tell others to take a risk that might lead to a £1,000 Dealer bill?

 

I was just not sure that was what you meant to say.

 

 

 

 

 

 

[flicka]

Am I missing something ?????

Firstly I don't leave batteries on constant charge, just top up as necessary.

BUT I can't understand why not. There are many Motorhomes doing just that as they have Solar Panels constantly feeding the batteries at the required level 24/7/365.

Is it implying that Solar Panels are therefore unsuitable for Motorhomes ????????????

 

 

[pepe63xnotuse]

flicka - 2016-10-06 11:45 AM

 

Am I missing something ?????

Firstly I don't leave batteries on constant charge, just top up as necessary.

BUT I can't understand why not. There are many Motorhomes doing just that as they have Solar Panels constantly feeding the batteries at the required level 24/7/365.

Is it implying that Solar Panels are therefore unsuitable for Motorhomes ????????????

 

 

But solar won't be feeding in at it's full-whack for "24/7/365" will it..

(hours of darkest, dull overcast skies, shadows,poor alignment etc etc), so probably doesn't compare with being plugged into the mains permanently ?

 

Unless someone is hell bent on running the likes of a heater and/or dehumidifier in their van, then I can't see why there's any real need for full time mains power feeding into it?

 

What's wrong with keeping it hooked-up but having the supply controlled via a timer?

(when stood, we'd leave ours "connected" and just switch it on in the shed as and when).

[StuartO]

aandncaravan - 2016-10-06 9:53 AMMy point was that you are actually advising people to ignore an expert company like Victron Energy who say long term float at 13.0v - 13.2v is the ideal. You say carry on with up to 14.2v. You are not saying it is what you would do, but actually advising people to ignore the experts. If thousands follow your advice and end up with duff batteries that then kill the charger units, that would be pretty disappointing consequences for them. Especially if it is a £600+ e-Box that blows up.On another recent post of Solar vs Generator you state that charging up a battery using a Schaudt charger takes forever. When it doesn't, they are one of the fastest for their size. You have previously stated you had two Gel batteries that were 10 years old. Gel batteries take longer to charge, but when a Gel battery ages it will take even longer to charge.A battery bank of 160Ah 10 year old Gels on a Schaudt 18A charger WILL take forever to charge and that was maybe what you experienced. Leading me to suggest that your two gels were past it years ago?Gel batteries in such a state may tend to absorb a higher float charge, to overcome all the internal corrosion and degradation, so that a higher Float for such batteries may actually be required, without any adverse effects. The impact on a modern quality battery that doesn't self discharge, unlike those 6 years ago, might be totally different? And that is another point, that things change. Even if your experiences of 8 years ago were relevant then, doesn't mean they are now with all modern battery types.Batteries have advanced so much in the last few years, that what was necessary to maintain them back then may not be appropriate now. We think the big battery manufacturers have been slow to take this on board, but are now.The reason Victron Energy have been the first is because they make batteries and Chargers. Not just badge other companies chargers, but have a charger R & D facility. They are one of the most Technically advanced battery/charger companies out there, because they do both so well. So while 13.8v long term EHU may have worked for you and the old Gel's, it is a small pool of experience. Even if the thinking/experience was appropriate 7 years ago, doesn't mean it is now.It doesn't seem to me to be the best background to actually tell others to take a risk that might lead to a £1,000 Dealer bill? I was just not sure that was what you meant to say.

 

Sorry Alan but I have to say that this post of yours is verging on scaremongering.

 

Victron might be proved right in due course but so far it's just an idea that a lower float voltage is better - and it is yet to be proved that this lower float charge will be better overall in operation in a motorhome system.  And the different batteries people choose are going be affected differently as well, so I just don't see a need to panic and replace my charger or my (recently replaced) leisure battery when they seem to be behaving well.

 

I know you have a lot of experience repairing motorhome chargers and sorting out failed MH systems but you do sometimes seem to adopt unnecessarily radical positions.  If my replacement gel battery fails prematurely I will have to replace it and I do accept that leaving the solar panels connected whilst in storage (and so subjecting the battery to up to 14.3 volts periodically) might be increasing the risk of premature battery failure somewhat.  But I don't see it as a big risk, so I'm prepared to take it because letting the solar panels keep the leisure battery topped up while in storage is a considerable convenience and a replacement battery (a Varta, as you recommend) would cost me less than £100.

 

[aandncaravan]

Stuart, I don't understand why you would say : "I just don't see a need to panic and replace my charger or my (recently replaced) leisure battery when they seem to be behaving well".

 

No one has suggested replacing any batteries or changing any chargers??

 

This advice is all about not leaving the vehicle plugged into EHU when you don't need to.

How is that scare mongering?

 

 

The first line of the Post is :

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

 

We suggested people look at how they use EHU because there is growing evidence to suggest neither the chargers or batteries benefit.

The same applies to Solar Charging, maybe review the current trend of leaving that active all the time.

 

We then presented evidence as to why it's not the best way of looking after your batteries or the chargers. That is all.

 

 

One thing that has come out of the post is that batteries do fail while on EHU, and if that happens when the vehicle is left unattended for weeks at a time, the consequences might be messy or worse.

Regardless of our Technical arguments, that one 'safety' argument on it's own is worthy of reviewing how EHU is used in storage.

 

 

 

 

 

 

[Will86]

For my two pennyworth of battery use.

 

We bought new a Rapido in 2006 and used it for 6 years. There were two large leisure batteries. It was plugged in to the mains all the time it was at home, WHY, because another similar M/H up the road was. My only puzzle was that the cells needed topping up far more often that I would have thought

 

Reading what has been said recently I assume the reason was that the batteries were being heated unnecessary, causing water evaporation.

 

If we had another similar M/H which is unlikely I would opt for an occasional EHU connection, thereby making the batteries work more. BUT continuous EHU might have assisted them to last longer as they worked less ?

 

 

[StuartO]

aandncaravan - 2016-10-06 2:36 PMStuart, I don't understand why you would say : "I just don't see a need to panic and replace my charger or my (recently replaced) leisure battery when they seem to be behaving well".No one has suggested replacing any batteries or changing any chargers??

Then I might have read too much from your post, which I read as starting to give dire warnings.  My apologies.

 

[Deneb]

I've been reading this thread with interest but haven't commented until now. I have very little experience with leisure battery chargers, having only owned a motorhome for a couple of months, and having had caravans for several years until about 11 years ago, but they didn't have modern chargers for the leisure batteries, so I used to isolate the batteries and just give them a top-up charge periodically with an automotive battery charger.

 

However, I owned a classic car for many years, which I used to keep permanently connected to an Optimate charger when not in use. I found that I was having to top up the cells every 2-3 months and the batteries were lucky to last 2-3 years. Eventually, I took the Optimate off of permanent connection and just connected it once a month for a day or so until it had run through its program and indicated a full charge. The battery subjected to that regime was 7 years old when I sold the car earlier this year and still going strong. I am therefore of the opinion that keeping even a smart charger permanently connected is not good for a lead-acid battery.

 

So far, my motorhome leisure batteries seem to be coping very well solely from a 100W roof mounted solar panel, even though it is the shade of the house for much of the day, and I'm following my previous plan in connecting a C-Tek charger to the vehicle battery once a month until it has completed a single program cycle and indicated a full charge.

[flicka]

pepe63 - 2016-10-06 12:02 PM

 

flicka - 2016-10-06 11:45 AM

 

Am I missing something ?????

Firstly I don't leave batteries on constant charge, just top up as necessary.

BUT I can't understand why not. There are many Motorhomes doing just that as they have Solar Panels constantly feeding the batteries at the required level 24/7/365.

Is it implying that Solar Panels are therefore unsuitable for Motorhomes ????????????

 

 

But solar won't be feeding in at it's full-whack for "24/7/365" will it..

(hours of darkest, dull overcast skies, shadows,poor alignment etc etc), so probably doesn't compare with being plugged into the mains permanently ?

 

Unless someone is hell bent on running the likes of a heater and/or dehumidifier in their van, then I can't see why there's any real need for full time mains power feeding into it?

 

What's wrong with keeping it hooked-up but having the supply controlled via a timer?

(when stood, we'd leave ours "connected" and just switch it on in the shed as and when).

 

Thanks pepe, trust me to miss the b********* obvious :$

[aandncaravan]

This thread has been recently referred to so just updating this with the current data.

 

We started the thread by advising that people review the time old practise of leaving a battery on permanent EHU charge.

Lots of evidence has emerged since suggesting we were right.

 

The web page has been updated with all the new supporting evidence : http://www.aandncaravanservices.co.uk/ehu-full-time-yes-or-no.php but a quick update added here.

 

Roadpro posted on their website the following note :

 

"'When used with a solar panel, a battery to battery charger or a mains charger that's on for days at a time, the electrolyte levels of Energy Bull batteries must be checked on a regular basis".

 

That suggests that some issue with long term mains/solar charging has highlighted an issue?

 

 

Yuasa seems to be the latest to caution against the practice. The website now states that Leisure batteries kept on a permanent 'float'/'trickle'/'maintenance' charge, "will result in internal degradation of the battery". Even when used with, "a well-controlled charging system".

 

As a result they suggest that batteries treated this way should be regarded as having a maximum two year life. See this extract :

 

Battery Maintenance in Non-Automotive Float Applications

1.Typical applications are motor-generators, stand-by applications etc. The Leisure Battery range is recommended for these applications; standard vehicle batteries are not suitable.

 

2. Batteries used in these applications should be changed every 2 years or more frequently. (Continuous charging, even from a well-controlled charging system, will result in internal degradation of the battery.

 

For full text read here : http://www.yuasa.co.uk/info/technical/need-know-batteries/

 

Before anyone starts arguing with us on this, it is text directly from the Yuasa website, so take it up with them.

 

We have been told that Exide now also advise against the practice because of battery damage but can't find anything on the Exide website.

 

 

An important point has come to light in the last few days, thank you Tom for the Papers.

That when Data centres permanently 'Float' charge National Grid Battery back-up systems, the batteries only have a decent life if kept cool. As already pointed out the Float voltage is usually 13.2v, not the 13.8v of a modern motorhome charger.

Just a 10 degree rise can half battery life, hence the best datacentre battery banks being in air conditioned environments, temperature is a major factor.

 

 

This suggests another angle to long term EHU/Solar charging, we had not fully taken in before :

A Motorhome on EHU in the freezing Cairngorms during the 4 months of Winter might suffer less battery degradation than a Motorhome on permanent Solar Charge during 2 months of a Spanish Summer?

 

Tom is hoping to get clearance to send us another Paper with more evidence we can publish, watch this space.