Yet another battery question

[arthur49]

Derek Uzzell - 2018-09-01 8:11 AM

 

Historically Rapido has remained faithful to Banner when factory-installing habitation batteries and, consequently, if Rapido had fitted an AGM or gel battery, I would have expected that battery to be a Banner product.

 

It’s been reported in the past that, when a Chausson dealership receives a motorhome, the vehicle will have no habitation battery pre-fitted. The dealership then has the responsibility for choosing an appropriate battery that will meet the eventual buyer’s requirements or wishes.

 

However, as far as I’m aware, a Rapido motorhome has always had at least one habitation battery in place when it has left Rapido’s factory in France and that battery has always been Banner-branded.

 

Could be Derek that the motorhome was fitted with Banner by Rapido but dealer changed it. That happened to us in Feb this year with Autotrail V-line. We tend to buy from dealer stock and when we first viewed the van it was fitted with a Banner (Energy Bull?) battery. When we picked up van it had a Numax fitted. Dealer told us Banner was knackered as it had run down too far too often ie abused and neglected. (We have 2 x LFD90s now)

[aandncaravan]

Derk, He has only just replaced the original, he wrote,

 

"The original battery in place was a banner 95751 which failed and when I checked it all the cells were low on fluid. I hadn't realised it was not maintenance free. It wouldn't hold a charge after that".

 

He then bought two Platinums, "bargain at £169 each" installed one with an intention to get the other added later.

 

 

 

Spirou, It isn't just the cable length and thickness it is the myriad of connections, relays, control box PCB tracks and other paraphenalia in between. It all takes a toll under high loads.

Just the 19amps load of a Fridge/Freezer is a big enough load to cause voltage drop and even just 0.4v is going to make a BIG difference to the charge rate.

 

 

It is typical of what we see.

Run down your own batteries to create a load and do the test on your own van and then tell me what you see, I would be surprised if it isn't approaching 0.5v

 

The Schaudt Elektroblock EBL 99 of Mr Nash's Burstner we saw just an hour before the Rapido had only a 0.2 v drop in the same test, but this manufacturer 'Group' take the Fridge feed from the Starter battery with all sorts of 'small' but contributory design features, meaning the drop at the Habitation battery is usually much less than the average, but still too low for ideal.

 

I think the manufacturers (and the B2B manufacturers in their instructions) need to be taking a feed for both charging and Fridge direct from the Alternator via a single run, fat cable all the way to the 12v controller.

 

Some of the systems still use the basic electrical design of a caravan, adapted for motorhome use, but not optimised. They just haven't get up with the demands of the modern motorhome.

 

 

 

I know, lets ask the Industry body, the NCC, to look at the issue and come up with some recommendations and then verify those with good practise................

 

Or would that be a bit like the 'Payloads' fiasco being campaigned by Motorhome Fun?

 

[spirou]

Willing to repeat with logging software, maybe even tomorrow but please let me know exactly what the starting conditions were. What was the leisure and starter battery voltage at start of test?

 

We have a dometic AES fridge, I presume you want it on max cooling power when on? I will cover the solar panel for the duration.

[Derek Uzzell]

aandncaravan - 2018-09-01 11:15 AM

 

Derk, He has only just replaced the original, he wrote,

 

"The original battery in place was a banner 95751 which failed and when I checked it all the cells were low on fluid. I hadn't realised it was not maintenance free. It wouldn't hold a charge after that".

 

He then bought two Platinums, "bargain at £169 each" installed one with an intention to get the other added later...

 

 

OK - I just thought it peculiar that a 2018 Rapido would have a Platinum AGM battery.

[aandncaravan]

spirou - 2018-09-01 12:36 PM

 

Willing to repeat with logging software, maybe even tomorrow but please let me know exactly what the starting conditions were. What was the leisure and starter battery voltage at start of test?

 

We have a dometic AES fridge, I presume you want it on max cooling power when on? I will cover the solar panel for the duration.

 

 

Derek, I suspect the high fluid loss in an even shorter time than 'normal' failure will be down to the Solar solution, it was very poor. Cheap components, but professionally done.

We have supplied tips so he can address this himself.

To help him with this I am also updating the Solar Power web pages (had chemo yesterday so can't do much today, zonked, but bored) with charts to show how the angle of the sun in the sky, day length power generated, plus comparisons between Aberdeen and Portugal, better show how things pan out.

 

 

 

 

Spirou, I would isolate Solar a few days before and let the batteries discharge.

 

The voltages will be whatever they are for your particular vehicle, just ensure the batteries are discharged enough to generate a charge load similar to that after a nights stopover.

 

So long as the Fridge is 'on' that is all you need, it won't draw more power for being on 'Full'. Many older ones don't even have the thermostat wired in the 12v circuit, more often than not the thermo just functions on Gas and 230v.

 

Just create conditions as close as you can to your typical 'stopovers' before then 'driving off' and charging everything up. That is when you will be close to the true loadings.

 

 

However, bear in mind that in your case, because you have slower charging Gel batteries, which take less current so place a lower load, it may not be the usual AGM/wet loadings, but I would still expect a noticeable voltage drop.

 

 

 

[spirou]

So the discharge part of the test is finished and the results themselves (see attached current vs voltage chart) are quite interesting on their own. An explanation is in order though.

 

Data was logged at 5 min intervals from the Victron BMV700 battery computer. The leisure battery is a TAB Motion Gel 125Ah (C20 rating) which we got fresh from the production line on December 2016 (so getting close to 2 years old). Battery was on charge by the solar panel on a dark, rainy day after coming back from a trip last night and NOT fully charged. Starter battery is the original FIAMM and it was at 12.62V when I started the test, will measure again tomorrow before engine starts.

 

In any case, leisure battery voltage was 13.3V when I covered the solar panel then turned on and plugged in everything I could think off apart from fridge and heating. You will notice the current line (orange) is not a straight line as whatever I plugged in (phone, various lamps, computer via inverter etc.) eventually got charged. All the lights and the radio add up to 4 amps, the rest were variables. There's a bump 1h into the test when current goes to 2A when I turned off some lights by mistake, followed by turning on the inverter to charge the logging computer (7-6A).

 

@ 2h20min into the test I turned everything off and let the battery rest for half an hour. Then I turned on only 2 lights (0,37A) for another hour and finished logging data after again turning everything off (EBL included) for the night.

 

But the interesting part, quite possibly somewhat baffling for beginners, comes when you look at the voltage line (blue). It dipped immediately from 13.3V to around 12.8V and effectively continued dropping for the entire discharge until the low point at 12.36V.

 

However, when discharge current eased mid test, as I mistakenly turned off lights, the voltage went up! As it did when I turned everything off later on. It shot up by 0.3V within a minute after current went to 0 then more gradually to 12,78V when I turned back on just two lights and again the same situation after that second mild discharge. Remember, there was no charging being done in between. This "sponge" behaviour is why voltage is a very, very bad indicator of state of charge while under load or charge conditions and why a battery computer (from Victron, Votronic/Büttner, Nasa Marine, Bogart Engineering, Mastervolt etc.) are a very useful, if not essential tool.

 

All in all, I discharged by 12.32Ah over about 4h total. For the record, our deepest discharge ever with this battery was 20.19Ah and previous minimum voltage was 12.48V. 10-12Ah is about average discharge level during skiing season for us so it should be representative. I will continue with the charging part of the test as Allan described tomorrow and I'm guessing the resting voltage in the morning will be in the 12.80-12.85V range. Would anyone care to bet? :-D

[kevina]

I'm in the middle of a test on my 5 year old gel batteries which have been heavily used for 4 months annually, half of which whilst on skiing trips using very little hookup.

 

I disconnnected them 5 days ago whilst reading 12.70v on the multimeter, the only load being a nasa monitor (control panel off and dump valve open). 24 hours later they had risen to 12.77v and they have remained there ever since.

 

It does indeed seem that the thicker plates in gel batteries have a huge "sponge" effect. I've always been aware that the recharging Ah seemed to fall short of what I'd expect from a supposedly depleted battery at, say, 12.2v (typically use >30Ah per day skiing). If I was able to let the batteries rest long enough without freezing I'd expect a significant recovery.

 

Disconnect your BMV700 Spirou, and you'll get another dozen or so millivolts!

[spirou]

all I can say is... lesson learned and point taken Allan :-D

 

First off, resting voltage was 12.83V so my guess yesterday was spot on.

 

I'm attaching 2 voltage/current charts, one is from the first segment of alternator charging after a night at rest. The second is the entire charging sequence until now. As I didn't see a point in keeping the engine running forever I switched off and hooked up to 230V. Then did two more tests with the engine running later into the charging cycle to see if battery SOC had any significant effect.

 

I've marked it on the charts but please consider the different logging intervals during engine ON and EHU ON charging.

 

During the engine ON scenarios I turned on the radio and fridge to load the leisure battery. As you can see it has quite an impact on the current going into the battery, and the voltage is a miserable 13.7-13.9V even after a significant time in absorption while on EHU. Obviously even lower during the first charging phase. In general the difference compared to what EHU was supplying was 0.2-0.3V under no load.

 

I don't want to bore you with more details but if anyone is unclear about anything regarding my test, just ask.

[aandncaravan]

Spirou, It isn't often I am wrong, I think the last time was at 10:59 03 April 1984........................ :D

 

Thank you from everyone on the Forum for going to so much trouble, you have hopefully just advanced many peoples knowledge.

 

 

Can you see how creating a bigger battery bank by adding batteries, especially AGM's, impacts all charging Alternator and 230v mains to the point they won't charge at all well.

In the case of a couple of big AGM's, just not at all?

 

 

That was why I was so impressed with Weldted's very simple, low cost but clever solution that makes such a difference to both Fridge efficiency and battery Alternator charging on the move.

 

 

His idea was to connect a small (low cost 650 watt, it should NOT be high power) Inverter to the Starter battery. The 230v output cable runs into the 'Wardrobe' to where the RCD is located.

 

A cut is made in the cable between the 230v EHU input box and the RCD and a female 16amp connector put onto the EHU input.

The existing RCD connected cable has a Male connector added and so does the new 'Starter; Inverter.

When you want normal EHU you 'reconnect' the female from the EHU inlet to the male going to the RCD.

When you want to 'power the van' from the Starter battery connected Inverter, you just switch 16amp plugs.

It is impossible to connect both Inverter and EHU supplies at the same time.

 

 

If you turn off all 230v appliances (except the Fridge) and start/run the engine with the Starter Inverter connected up to power the van 230v circuits by plugging the Inverter 16a plug into 'the RCD', it will be this circuit that runs the Fridge on 230v (no load on the 12v at all so zero drop) and it will be the Starter battery (actually the Alternator) that also now powers the mains 230 charger to charge the habitation batteries.

 

It won't matter if the Inverter only gets '13.4v' instead of 14.4v, because the charger will still get 230v to charge the batteries at 14.7v or whatever you decide the charger output is.

 

The Fridge works more effectively on 230v, with thermostat operation so actually now only on 30% of the driving time instead of most vans 100%, 12v time, runs cooler, etc.

 

 

In many vans, just as Welted did, you will need to augment the mains charge for optimum performance, I think he bought a Victron, which also had 13.2v long term float charging to further preserve battery life again.

 

He reports very good results, and you can see that just removing Fridge 12v from the equation has a positive impact.

 

 

In my opinion a much better solution to a B2B as it adresses two primary issues and far more flexible, see : https://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/Technical-Alternator-or-Inverter-charging-/48365/

 

For example it turns the engine into a more effective short term 'on site generator' as well with almost double the 'generation' power if you optimise the mains chargers, batteries, etc.

 

The peak load on the Starter battery is only a few amps more than 'in raw 12v mode' so very efficient, when the Fridge reaches 'temperature' on 230v, obviously that load reduces, so the overall loading is less exceeding that of the usual B2B which often creates other issues as the usually bypass the existing vans electrics/control.y .

 

Obviously if anyone adopts it you should employ a qualified 230v electrician, for maximum safety and all other safety warnings apply.

 

 

 

 

[aandncaravan]

Sorry second to last sentence was wrong, what reads as :

 

"The peak load on the Starter battery is only a few amps more than 'in raw 12v mode' so very efficient, when the Fridge reaches 'temperature' on 230v, obviously that load reduces, so the overall loading is less exceeding that of the usual B2B which often creates other issues as the usually bypass the existing vans electrics/control".

 

Should read

 

The peak load on the Starter battery is only a few amps more than 'in raw 12v mode' so very efficient, when the Fridge reaches 'temperature' on 230v, obviously that load reduces, so the overall loading is less. Exceeding the efficiency of the usual B2B by quite a margin. They can also create other issues as they usually bypass the existing vans electrics/control.

 

 

[Ocsid]

Now should that inverter be PSW or can you get away with a MSW, just a bit concerned about my rather delicate Schaudt Elektroblock?

[aandncaravan]

Good point.

Never anything other than Pure Sine Wave in a modern Motorhome where sensitive electronics might be installed, and suggest you go for medium pricing not cheapest.

 

Generally, PSW Inverters are much better made, even the better ones are not expensive in 650watt sizes and a typical charger takes 300w and a Fridge up to 180w'ish so it shouldn't get overloaded.

 

 

No recommendations but something like this 600w (continuous not just peak) 12v :

https://www.tlc-direct.co.uk/Main_Index/Transformer_Index/Inverters/index.html#Inverters_Pure_SineA

 

It has 1amp USB charging as well.

 

[aandy]

Those tests certainly put my "switch things on for a few hours every day for a week and see what's left at the end" approach to shame.

 

I survived six days off grid, with the batteries down to 12v at the end. The lowest I have previously seen is 12.2v. After a four hour drive home I left the van on hook-up until the readout on the ECU was showing 13.6v and 0amps, at which point I switched off at the socket in the garage and on the ECU. That is my usual routine and, without fail, the reading after 24 hours is always 12.6v. On this occasion the reading was 12.8v and it remains so after a further 24 hours. Is it possible that a slightly deeper than usual discharge has somehow had a beneficial effect, or is it more likely to be a brief rally before they finally give up?

 

Apologies in advance for what is probably a stupid question, but all I know about batteries is what I've picked up on here (thanks again Allan) and I only understood about half of that.

 

Andy

[aandncaravan]

Aandy, that is good going, 6 days shows what can be done if you need to.

.

12v is quite deep for most batteries but you probably have not stressed that particularly battery that much.

 

While it needs really careful TLC, if it does get the ideal care, they are capable of deeper discharging than many.

 

In most cases a lead battery will not benefit from being discharged and recharged, it will always lose a little bit of capacity.

Ni-cad batteries can have a memory effect, but Lead batteries always benefit from shallow discharging, unless they have been standing a long time and suffered acid stratification.

 

However, your 'charging regime' may be relevant? You might not be leaving it on charge long enough. See our web page on how chargers work, http://www.aandncaravanservices.co.uk/how-does-a-charger-work.php because most won't have got 2 big batteries fully charged by the time they drop to 13.8v.

That is how car chargers work.

 

Motorhome chargers 'boost' for x hours, typically 4, before dropping to 13.8v float, regardless of how 'full' the battery is. It's a safety thing.

 

Leave it on mains charge at least 4 days after use like you have given it.

 

 

 

 

 

[plwsm2000]

Sorry to put a spanner in the works to an otherwise good idea, but the thought of running an inverter and EBL charger while the vehicle is in motion is quite scary. It invalidates the EMC testing and certification that would have been considered when the vehicle CofC was produced.

 

Obviously EBL chargers would have been designed to operate on EHU and not when the vehicle is in motion. These chargers and inverters contain high power and high frequency switching electronics that can generate quite a lot of electrical noise if not designed and connected up properly. There is a small chance these could interfere with ABS, Airbags or other safety critical electronics on the vehicle.

 

I believe many British vans have an "EMC relay" to disable the habitation electrics when the engine is running for this very reason. Using an inverter to the EBL while traveling will bypass these safety measures.

IMO, the chance of anything going wrong maybe quite small, but the repercussions could be catastrophic.

 

 

[aandncaravan]

plwsm2000 - 2018-09-02 6:36 PM

 

Sorry to put a spanner in the works to an otherwise good idea, but the thought of running an inverter and EBL charger while the vehicle is in motion is quite scary. It invalidates the EMC testing and certification that would have been considered when the vehicle CofC was produced.

 

Obviously EBL chargers would have been designed to operate on EHU and not when the vehicle is in motion. These chargers and inverters contain high power and high frequency switching electronics that can generate quite a lot of electrical noise if not designed and connected up properly. There is a small chance these could interfere with ABS, Airbags or other safety critical electronics on the vehicle.

 

I believe many British vans have an "EMC relay" to disable the habitation electrics when the engine is running for this very reason. Using an inverter to the EBL while traveling will bypass these safety measures.

IMO, the chance of anything going wrong maybe quite small, but the repercussions could be catastrophic.

 

 

 

Sorry to disagree, but this whole area is just full of so much inaccurate garbage.

The UK do not do ANY EMC testing AT ALL, they rely on installing kit that has approval before it is fitted.

Ask to see the EMC certificates!!!

It was based on 'legislation' that was out of date before it was even written.

 

German, Italian, French, Dutch, U.S, etc. built vans do not disable ANY 12v electrical items, it is purely a British thing that is a pain in the neck for everyone, particularly those who WANT/NEED to see how rubbish their Alternator charging is!!!

 

It is this same terrible adoption by the UK of this phoney EMC 'needing' to disable 12v that has hidden poor alternator charging so long. My pet hate,

 

 

 

12v vehicle electrics on cars and motorhomes have to be SO RESILIENT to all manner of electrical disturbance in the air waves ( like driving past Police radio masts with ultra high power 60 mile power operation, Cell masts, etc) that they have been designed to be bullet proof.

 

Sorry but that is just scare mongering and it is about time the UK moved with the rest of the World.

 

 

Now, being concerned about the Electrical energy from a Nuclear Blast disturbing my ABS is something we should all worry about.....................

 

 

[aandy]

Thanks Allan. It was at 14v+ and around 4 amps for several hours so when it dropped to 13.6 and 0 I assumed it had finished. I had been wary of leaving it on float after reading (and no doubt misunderstanding) one of your earlier posts. I'll put the charger back on now.

 

We were not in the van very much while away so did not use a lot of power, and with a low consumption Avtex TV (no more than one or two hours a night) and all LED lights I had expected 2x100ah batteries to do rather better. Evidently I was expecting too much of them, so perhaps replacement is not as imminent as I had thought. While I can guestimate the usage on things like TV and lights, high consumption in short bursts items such as water pump and cooker and boiler fans are probably where my calculations fall down.

 

Andy

[arthur49]

aandncaravan - 2018-09-02 4:21 PM

 

In many vans, just as Welted did, you will need to augment the mains charge for optimum performance, I think he bought a Victron, which also had 13.2v long term float charging to further preserve battery life again.

 

 

I wondered about this Allan. My van has the basic EC155. I implemented your 'beefed' up wiring and split charge relay recommendation months ago, and now get 14.34v at habitation batteries with engine running, fridge off or on gas.

 

Now how to beef up charging on EHU? Is the Victron charger above in addition to standard van charger or instead of?

[aandncaravan]

aandy - 2018-09-02 6:51 PM

 

Thanks Allan. Evidently I was expecting too much of them, so perhaps replacement is not as imminent as I had thought. While I can guestimate the usage on things like TV and lights, high consumption in short bursts items such as water pump and cooker and boiler fans are probably where my calculations fall down.

 

Andy

 

Andy, Only reliable way we have found to test a Motorhome battery, is listed at the bottom of this web page :

http://www.aandncaravanservices.co.uk/battery-technology.php

 

If a battery has been 'exhausted' yet has no faults in the plates, i.e no shorts, no sulphation, etc. it can hold a steady voltage for weeks, yet not have any real capacity.

 

 

 

 

[aandncaravan]

arthur49 - 2018-09-02 7:10 PM

 

aandncaravan - 2018-09-02 4:21 PM

 

In many vans, just as Welted did, you will need to augment the mains charge for optimum performance, I think he bought a Victron, which also had 13.2v long term float charging to further preserve battery life again.

 

 

I wondered about this Allan. My van has the basic EC155. I implemented your 'beefed' up wiring and split charge relay recommendation months ago, and now get 14.34v at habitation batteries with engine running, fridge off or on gas.

 

Now how to beef up charging on EHU? Is the Victron charger above in addition to standard van charger or instead of?

 

 

Arthur, perfect timing because it shows how few wiring changes you actually need to make to make a big difference,

 

As you know your EC155 normally has a fixed 13.8v (no variable voltage rate at all) but does vary the current from it's peak 10 or 20 amps downwards depending on spec.

 

 

The EC155/160 usually has a charger inside the big metal case, but a standalone Victron mains charger can be wired directly into the EC155 housing so that all functionality remains exactly as before, including switching between the two chargers.

The new Victron charger can be wired so BOTH the existing charger (but mains 230v plug pulled if required so it is temporary non operational) or the Victron can be used.

 

If a 12v, 2 pin plug is used to wire in the Victron, it can be just pulled from the installation to return it to standard when you sell up.

 

It is not hard to do, just open the case (watch for ridiculously short cables) and trace the charger 12v output. Splice the Victron output into this.

 

Take the 230v plug from the 'old' charger and make up something like the photo, with a Surge/Spike 13a Adapter to create a 'Double' 230v socket. See photo.

 

 

Control of which charger is operational at a time, is done by juggling the 230v mains inputs. We have seen a Spike/Surge 13a adapter with switches which makes this easier.

 

 

That advice also applies to most of the Sargent ECxxx range with a separate/standalone charger.

[arthur49]

Thank you Allan. Thats my next 'project' sorted then :-D

[plwsm2000]

aandncaravan - 2018-09-02 6:46 PM

 

 

Sorry to disagree, but this whole area is just full of so much inaccurate garbage.

The UK do not do ANY EMC testing AT ALL, they rely on installing kit that has approval before it is fitted.

Ask to see the EMC certificates!!!

It was based on 'legislation' that was out of date before it was even written.

 

German, Italian, French, Dutch, U.S, etc. built vans do not disable ANY 12v electrical items, it is purely a British thing that is a pain in the neck for everyone, particularly those who WANT/NEED to see how rubbish their Alternator charging is!!!

 

 

12v vehicle electrics on cars and motorhomes have to be SO RESILIENT to all manner of electrical disturbance in the air waves ( like driving past Police radio masts with ultra high power 60 mile power operation, Cell masts, etc) that they have been designed to be bullet proof.

 

Sorry but that is just scare mongering and it is about time the UK moved with the rest of the World.

 

 

Now, being concerned about the Electrical energy from a Nuclear Blast disturbing my ABS is something we should all worry about.....................

 

 

 

Unfortunately it is not complete garbage but I do think there is a lot of scare stories about and that that British manufacturers are being over cautious.

 

The reason why UK manufacturers do not do any extra EMC testing is because they don't need to if the habitation electronics is off when the engine is running. As I say, I think they are being over cautious and I would be surprised if German/French manufacturers do any EMC testing either but they probably do a better assessment of the risks (it is not always compulsory to do the testing as a detailed technical assessment can sometimes be done instead)

 

There are fundamentally two types of interference - radiated and conducted. The police radios, Radar, mobile phone masts etc all radiate RF at high levels and are above 30MHz and are external to the vehicle. Conducted interference is more to do with noise propagated on internal wires and cables and as they are at lower frequencies, they behave quite differently. The noise is generated by electrical devices connected to the internal wiring. When Fiat/Ford etc. ran EMC tests on their base vehicle, they would have used a typical or worse case equipment level, and I am fairly sure they would not have included an inverter, charger, fridge etc. in the test vehicle.

The way that electronics are protected from these two sources use different principles and it is quite possible (and very common in my experience with EMC work) for electronics to be immune to radiated interference and be very poor at conducted interference (and vice versa).

 

Maybe British motorhome manufacturers should take advise from some EMC specialists and hopefully do away with these "EMC relays". I also think there is no need for them but I am not the one going to jail if they don't do it properly.

 

[url=] http://www.autoemc.net/Papers/Other/EMC&CJ50_PP_AM.pdf

[aandncaravan]

I think the number of people who start their motorhome engine while plugged in to EHU and the ECU lets the engine run ok is pretty much proof just how how robust motorhome 'chassis' 12v are. No CANBUS errors yet, about as sensitive as you can get.

 

 

I also think the number of people running a myriad of different TV's, ultra sensitive Sat systems, laptops, WiFi's, microwaves, etc in motorhomes while on EHU or Inverter, etc. are also testament to the lack of interference from standard devices shows it isn't a risk.

 

 

Sorry, but the 'Going to jail' just reinforces the scare mongering approach taken.

 

 

 

[spirou]

I probably won't be doing this dual charger modification but I'm just trying to figure this out. If I understand correctly you just wire them in parallel on the output and input side but how do you switch the inputs other than manually unplugging one, hoping you took out the one not supplying the sockets with 230V but the one wired only to battery? Also, won't they be interfering with each other?

 

Lets say one has a 2h timer, the other 8. One a 13.8V float, the other 13.2V. It seems a bit convoluted. I know Schaudt makes extra chargers for larger battery banks so those are trully plug&play if your base EBL is already a Schaudt but I'd be a bit hesitant to mix them up across brands. Just a feeling, nothing else.

 

I've noticed that thread with starter battery inverter as pseudo EHU before but haven't really looked into it. At first look seems quite an undertaking to make that conversion if you don't plan for it in the first place. While doing the test today I tried, but couldn't figure out an easy way to upgrade to heavier wiring and that's not even my first priority on the list of things to fix. Batteries at opposing ends of the van pretty much include ripping out some furniture and trim, or wires stuck somewhere midway as you try to pull them through.

[aandncaravan]

spirou - 2018-09-02 8:25 PM

 

I probably won't be doing this dual charger modification but I'm just trying to figure this out. If I understand correctly you just wire them in parallel on the output and input side but how do you switch the inputs other than manually unplugging one, hoping you took out the one not supplying the sockets with 230V but the one wired only to battery? Also, won't they be interfering with each other?

 

 

I don't think anyone in the world would run a 1980's design charger alongside one designed last year, but keeping them both in place keeps everything original which is important to some, and easy return to a single charger.

 

It allows them to be tested in isolation once in a while and gives future flexibility should one fail.

 

You don't need to switch inputs/outputs, if it has no 230v going in, it's just dead.

 

It also means that Sargent won't kick off if you have to send them the ECxxx housing for repair and there is a Cuckoo in there.

 

You are fortunate to have a 'real' charger, one of the best, not everyone in the UK is.

 

So if it easier to leave both 'operational but controllable, it's silly not to.

 

 

Sorry if I sound grumpy, I am.

In a lot of discomfort tonight,