Flat Batteries on my Motorhome

molly 2

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I have flattened the starter battery on many cars , always recoverd and gave good service , my veiw is given a second chance .
 

wildebus

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Phil, to be fair, YOU may not have mentioned British Motorhomes or Sargent systems, but the original poster with the flat battery problem DID (he certainly mentioned Sargent and so by extension would have a British MH), and the replies (at least mine and canalsman) took that into account when saying it should not be possible to do what you later said was possible with your Hymer.
 

Nabsim

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I have flattened the starter battery on many cars , always recoverd and gave good service , my veiw is given a second chance .
So have I Baz, it’s the capacity that will probably (but hopefully not) be damaged on the leisure bank. OP will have to see how long he can run on just his battery’s if they recharge okay then decide if they are good enough for his needs

Edit: only 3 way fridges I have had were in caravans and I could set those to run on 12v with the car unhooked and no 240v. Will depend on OP setup
 

colinm

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Our Globecar (part of same group as Hymer) has an EBL and (non AES) Dometic, whilst the EBL has to be switched on for 12v to work the cooling it won't do that if engine isn't running.
 

centerman

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Hi All, Sorry I have not replied to your posts have been away till today. The fridge in my Swift Kontiki 645 is 3 way and can be operated on 12volt when engine was not running it has a auto switch over when being in Gas or on mains it will switch to 12volt as you drive and off when stop if was previously on Gas it will auto start on gas.
So I am convinced it was fact I had switched it to 12volt thinking only be parked up for few days had been like this for a month oops! leisure batteries were actually all 95Amp and showing only 6.2 on the meter. I took one back to Halfords and they changed it on its warranty. reconnected this in motorhome battery container. This then took the van up to 13,7 and all worked including the solar panels where working showing charge rate. engine battery still flat engine wouldn't start so had recovery out and jump started it then had a nice drive for 40 minutes and battery starts fine now motorhome back on driveway and onto mains. Following day I had disconnected the the 2 batteries in my battery bank to check them as the breakdown chap seemed to think something in the bank was leaking due to eggy smell and damp area, positive terminals corroded on both and Negative on one also corroded? I have bought a NOCO Genius 26000 thinking the batteries would be stuffed once I cleaned all terminals up connected to charger AGM cold and within couple of minutes showed both when done fully charged and show 13.6 each on meter.
Given in 2020 last year I had 2 batteries in the bank area had blown up they were in bits loads of acid had been sprayed out in this locker so removed debris and treated the locker with Bicarbonate of Soda which I was told is the same of Baking Soda to neutralise the acid. Thought this had worked but if the ones that were fitted this time are not leaking which cleaned up there is no sign of leakage it is still corroding in the locker and metal L fitting holding cupboard down are black and rotted through. A layer of plywood locker is damp feeling and white powder film I now peeled it off to next layer around lower edges of locker and repeated the area with Bicarbonate Soda leaving it to dry out and then refit batteries. I will may book this into an auto electrician to have charging ok confirmed as you can clearly see I am out of my depth with this problem.

I tested the wires going into the attached leisure battery to test charging rate and it shows 13.6 on meter which would be correct I assume. But batteries exploding and sign of damage in locker this could the indication of over charging? and if so is this likely to happen again is there any other method of getting rid of the acid by neutralising it. Any Ideas
Cheers
 

centerman

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Also meant to mention the engine battery is drawn on if leisure battery is depleted so once solar panels where fitted I fitted a charger linked to the engine battery so once leisure battery's are full spare power is pushed onto engine batterie till it is full and have not had any further problem till now
 

wildebus

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sounds most unsual for a sargent equipped motorhome to have the 12V active when engine not running, but if it does it does :)

What model Sargent unit is fitted in your motorhome. Some of them are set to charge at a rather high rate.
 

centerman

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My Sargent unit is EC200 and fridge is a domestic and has 12 volt Gas and 230v and warns the refrigerator should only be used on 12volt while the motor is running otherwise it will be discharged within a few hours teaches me to read the manual in future.
 

wildebus

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I think the EC200 is fairly normal. I was wondering if you had a EC325 .... that unit apparently charges the batteries at up to 18V according to the user guide (seems a bit extreme to me!). I have the EX325 but have disabled the charging within it and use external charging only.
 

trevskoda

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I would glass fiber out the battery box area for sure and put a floor vent hole in it, sounds something is not right with the charging setup.
 

centerman

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I plan to use chlorinated Rubber paint which is Acid resistant and can match the locker colour. I looked into where to put vent, if it is battery gas this is lighter than air so goes up apparently so would not go to floor? I contacted a major battery supplier. They explained that you fit a vent tube to top of battery a in one side route this pipe down through floor and the other side should have a vent bung in to stop gas escaping. My Halford batteries supplied in 2020 had neither so the gas can escape into locker and can be ignited easily which is what clearly happened. I went and spoke to manager there and explained the vent and bung should have been in the original batteries but was not fitted showed him they are on ones on shelf and pointed out the one they exchanged saturday again had neither fitted. But result he changed all batteries to new Yuasa leisure battery's result so starting with new. I agree still thing some over charging problem in set up is going on waiting to have this checked by local auto electrician but they are fully booked till week after next. Bit of a pain will try to find a mobile guy.
 

trevskoda

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I plan to use chlorinated Rubber paint which is Acid resistant and can match the locker colour. I looked into where to put vent, if it is battery gas this is lighter than air so goes up apparently so would not go to floor? I contacted a major battery supplier. They explained that you fit a vent tube to top of battery a in one side route this pipe down through floor and the other side should have a vent bung in to stop gas escaping. My Halford batteries supplied in 2020 had neither so the gas can escape into locker and can be ignited easily which is what clearly happened. I went and spoke to manager there and explained the vent and bung should have been in the original batteries but was not fitted showed him they are on ones on shelf and pointed out the one they exchanged saturday again had neither fitted. But result he changed all batteries to new Yuasa leisure battery's result so starting with new. I agree still thing some over charging problem in set up is going on waiting to have this checked by local auto electrician but they are fully booked till week after next. Bit of a pain will try to find a mobile guy.
Clor rubber paint is ok but not foolproof, and its a single pack, we used it mainly for outside of tanks but would line the inside with epoxy or grp depending on the use, a small one I did.
oil tank.jpg
 

Chrisinchip

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my half-pennies worth, bit late in the day because came on to this site to ask my own question about batteries. I feel there are multiple problems.

Recovering flattened batteries: Try recharging them, nothing to lose. 40 mins driving won't do it. Put on a charger and leave to charge for a few days. (N.B. charger must be compatible with the battery type - Wet/Flooded, AGM, GEL etc. so best use a decent smart charger). As somebody has already commented, the capacity will probably be reduced by this mishap and therefore their life will have been shortened but hopefully they will get you by for the time-being.

Why were LBs flattened: A few things to check here because there should be safeguards to prevent them dropping so low: [EDIT: Apologies, I had forgotten Centreman's post describing that the fridge is only designed to use 12v off a running engine since it is an absorption (gas) fridge, so I've deleted the content under this heading! ]

Why was the starter battery flattened: I have read the other comments including about fancy auto switching fridges - it is all beyond my experience. So if it were my MH I would be drawing out how the electrics are wired and configured, and aim to isolate the starter battery (SB) from the LB circuit. I'd definitely disable any config that switches an appliance over to the vehicle when it is not running. It is so undesirable to allow the habitation electrics to flatten the SB unexpectedly. Not as easy as it sounds though. Not only do you need to check for other appliances and devices draining the battery, all the possible cross feeds need to be explored. An example that, though not specifically relevant here, demonstrates peculiar interactions: Solar Technology UK solar panel controllers have twin battery capability but if the two batteries that are connected into B1 and B2 on the controller share a neutral/ground (quite common in a MH I would have thought) the manufacturer reports that the controller can get confused and flatten a battery. Oops, awkward.
Check for stuck vehicle alternator charging relay - possibly embedded in a controller. You may need to remove fuses to isolate the LB side from the LB itself. You'd be looking for an "open circuit" voltage (low and fluctuating) with the engine off and a 13v+ with the engine on.

Battery charging: AGM batteries need a higher bulk charge voltage so will never reach full charge and their life shortened if the charger is using a profile suited to the trad wet/flooded battery. Could it be that you were never charging your battery up to max charge? Given the earlier problems with batteries I would want to understand and check the battery charging systems down to the Nth degree - but that's me!
  1. EHU Charging: I don't have personal experience of the Sargent PSU2007 but quickly checked its manual and could not find instructions for setting up the battery type. Happy to be corrected, however I have read elsewhere a rant about how caravan and MH manufacturers are fitting AGM batteries with chargers that lack an AGM config.
  2. Solar charging: The solar charge controller also needs options to select battery type if using AGM batteries in order to maximise the charge and lifespan.
  3. Vehicle alternator charging: I have not a clue how this is controlled with the latest technologies and this was the question I logged on to ask! Old school, a split charge relay would sort out the connecting in of the LB when the engine is running and isolate the LB when not running.
Something that I am not sure how much to worry about is if the SB and LB are different battery types. If the vehicle has stop-start the SB is likely AGM, otherwise probably trad technology. MH and caravans have been installing AGM for a while but there will be a mix of technologies in use out there. I am skeptical that all the 3 charging routes accommodate the different battery technologies across the SB and LB and think we need to be aware of the limitations of the charge set up, almost on a case-by-case basis. Scary!
 
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centerman

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Hi All I
decided to strip out the locker were my battery bank is kept and re build it as the wood was saturated in Acid i assume from the earlier problem when batteries had exploded last year, so not worth coating better to replace all done now. I realised the batteries that exploded i had replaced in Halfords had no drains and plug in manifold. So went back to them to complain and had all 3 replaced under warranty. I used google how to check all charging circuits were working correct which they were. So new batteries are SMF Yuasa YBX3019 95 Amp with fitted bungs on negative side and drain on positive side down through floor to drain any gas outside of locker. All seems well so ready to get away many thanks for all your feedback.
Brian
 

wildebus

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my half-pennies worth, bit late in the day because came on to this site to ask my own question about batteries. I feel there are multiple problems.

Recovering flattened batteries: Try recharging them, nothing to lose. 40 mins driving won't do it. Put on a charger and leave to charge for a few days. (N.B. charger must be compatible with the battery type - Wet/Flooded, AGM, GEL etc. so best use a decent smart charger). As somebody has already commented, the capacity will probably be reduced by this mishap and therefore their life will have been shortened but hopefully they will get you by for the time-being.

Why were LBs flattened: A few things to check here because there should be safeguards to prevent them dropping so low: [EDIT: Apologies, I had forgotten Centreman's post describing that the fridge is only designed to use 12v off a running engine since it is an absorption (gas) fridge, so I've deleted the content under this heading! ]

Why was the starter battery flattened: I have read the other comments including about fancy auto switching fridges - it is all beyond my experience. So if it were my MH I would be drawing out how the electrics are wired and configured, and aim to isolate the starter battery (SB) from the LB circuit. I'd definitely disable any config that switches an appliance over to the vehicle when it is not running. It is so undesirable to allow the habitation electrics to flatten the SB unexpectedly. Not as easy as it sounds though. Not only do you need to check for other appliances and devices draining the battery, all the possible cross feeds need to be explored. An example that, though not specifically relevant here, demonstrates peculiar interactions: Solar Technology UK solar panel controllers have twin battery capability but if the two batteries that are connected into B1 and B2 on the controller share a neutral/ground (quite common in a MH I would have thought) the manufacturer reports that the controller can get confused and flatten a battery. Oops, awkward.
Check for stuck vehicle alternator charging relay - possibly embedded in a controller. You may need to remove fuses to isolate the LB side from the LB itself. You'd be looking for an "open circuit" voltage (low and fluctuating) with the engine off and a 13v+ with the engine on.

Battery charging: AGM batteries need a higher bulk charge voltage so will never reach full charge and their life shortened if the charger is using a profile suited to the trad wet/flooded battery. Could it be that you were never charging your battery up to max charge? Given the earlier problems with batteries I would want to understand and check the battery charging systems down to the Nth degree - but that's me!
  1. EHU Charging: I don't have personal experience of the Sargent PSU2007 but quickly checked its manual and could not find instructions for setting up the battery type. Happy to be corrected, however I have read elsewhere a rant about how caravan and MH manufacturers are fitting AGM batteries with chargers that lack an AGM config.
  2. Solar charging: The solar charge controller also needs options to select battery type if using AGM batteries in order to maximise the charge and lifespan.
  3. Vehicle alternator charging: I have not a clue how this is controlled with the latest technologies and this was the question I logged on to ask! Old school, a split charge relay would sort out the connecting in of the LB when the engine is running and isolate the LB when not running.
Something that I am not sure how much to worry about is if the SB and LB are different battery types. If the vehicle has stop-start the SB is likely AGM, otherwise probably trad technology. MH and caravans have been installing AGM for a while but there will be a mix of technologies in use out there. I am skeptical that all the 3 charging routes accommodate the different battery technologies across the SB and LB and think we need to be aware of the limitations of the charge set up, almost on a case-by-case basis. Scary!
Just a comment on the AGM battery charging thing .... I think I know the site you are referring to, and while it has some good info on it, it also has some wrong information which is very misleading (one of the reasons why you cannot post a link to it from here without it being censored).

There is no such thing as "an AGM battery". They are not a single design needing a single way to charge them up. There are different types of AGM batteries with their own requirements. For example, I have 3 AGM batteries in my Motorhome... They are Lead-carbon AGM and they have an absorption charge voltage (this is what you mean by Bulk, I think in fact) of between 14.2V and 14.6V. I set my charger to 14.2V. my previous batteries were also Lead Carbon AGM Telecom batteries and they lasted best with a 14.1V charge.
There are also, slightly oddly, two different approaches with 'normal' (non Lead-Carbon) AGM. There are European AGMs, and Far East AGMs. The European made AGMs want a higher absorption voltage of 14.7V, whilst the Far East AGMs prefer 14.4V.
All a bit random in many ways when you just want a buy a bleeding battery!

My advice would be be check the battery data sheet to see what is recommended and if your system can provide that.
If there is no datasheet available for the battery and the seller cannot provide - knowledgeably, not guesswork - the information for it, just don't buy that battery as you have no idea how best to treat it.
Ask the battery vendor for advice if you are not sure if a battery will work in your setup.

And finally, personally I would not buy a battery for a motorhome or campervan that needed to be installed in the living area and vented externally. Or any battery at all that ever needed topping up (which are most of the above ones that need venting).
 

Markd

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Definitely something not quite right somewhere if you've had battery explosions and depletions.
One reads that Sargent chargers of that vintage aren't too smart about dropping charge rates and I wouldn't leave mine on for more than a few hours. Not a problem because I have solar and Votronic MPPT regulator to keep all mine topped up nicely.
As Wildebus says Swift electrics are normally set up to only allow 12v to the fridge heater when the engine is running and if you have AES it should call on gas when you turn that off.
The fridge does have 'permanent' 12v to run interior light and any electronic controls.

It will certainly be worth checking how the fridge cooling circuit is wired up because at 15+ Amps draw it will soon pull down your battery bank overnight and would need a lot of solar to keep up in the day and at this time of year that's unlikely.

Glad to hear that Halfords have been so helpful - slightly amazed actually but I suppose their margins allow for the very occasional leisure battery collapse to be affordable.
Or more likely they don't really know what happened!
 

r4dent

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..... only allow 12v to the fridge heater when the engine is running and if you have AES it should call on gas when you turn that off.

A bit misleading. It does not select gas immediately, so don't panic if the switch to gas is delayed.

Quote from manual "In order to prevent unintended switching to gas operation during refuelling, the electronic
system starts gas operation of the refrigerator after the motor has been turned off for 15 minutes. "
 

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