More Battery Advice Needed

Langtoftlad

Langtoftlad

LIFE MEMBER
Joined
Apr 12, 2011
Posts
9,499
Likes collected
167,954
Location
Langtoft, South Lincs
Funster No
16,024
MH
WildAx Aurora FB [PVC]
Exp
Since 2015
Both leisure & vehicle batteries have been left standing for a while and are pretty flat.
They also needed topping up.
I plugged in the EHU last night.

Just been out to check on them, control panel reporting about 60% leisure
Don't know the specifications of the CBE charger

While I was in the van, the CO alarm went off !
I believe that can happen if the batteries are offgassing hydrogen?
Obviously I opened all the doors & got out
I disconnected the EHU

I took the alarm out of the van and changed its batteries. Put it back in the van.
The alarm is now going off again but the van is off hookup. Opened the doors again
Taken the alarm into house the kitchen, and it's still intermittently still going off - faulty alarm?
Seems to have stopped now, taking time to clear?

Batteries were warm to touch, one warmer than the other but not "ouch" hot.

At the time I pulled the EHU, my multimeter read 12.4v
About an hour+ later the readings are - 11.85v

More concerning is I can faintly hear the batteries simmering [ not bubbling like a kettle ]
The van is not now on hook up, but there's the solar panel.
I've pulled a fuse labelled 'SOL' and the solar controller led has gone from green to amber but I'm not 100% convinced the solar panel has been isolated.
Should I flip this circuit breaker?
20240602_135121_copy_600x1056.jpg




Should I leave it all alone - it's booked in at the end of August for some work including replacing the leisure batteries. They are 7years old.

I'm not planning any trips in the van before then, except maybe a couple of days out, and maybe 2-3 nights locally at Lydon Top [ I expect I can manage with just my Anker Powerbank & gas if I have no onboard 12v ]

I'm thinking of seeing if my local MOT/Servicing place can test the vehicle battery & replace if necessary next week.
And then should I buy a basic charger to keep the vehicle battery charged up independently of the onboard system

All comments & advice welcomed, especially on safety,
but please don't suggest doing work myself, I'm not capable, don't have any tools and honestly lack the motivation.
 
At 7 years they'll be on their last legs so yes, replace.
The engine battery may fair a bit better but get a garage/tyre depot etc to test it.
If you use the van keep checking the battery for a rotton egg smell (hydrogen sulfide) and if present stop using.
Hydrogen sulfide gas is extremely explosive.
 
pappajohn said:
If you use the van keep checking the battery for a rotton egg smell and if present stop using.
Click to expand...
No smell detected
I've never listened to my batteries before - is a small amount of "simmering" and heat to be expected?
 
Personal opinion but if my batteries were gassing enough to set the alarm off I wouldn’t wait until the end of August. I would remove them immediately. Garage and tyre depots usually use battery drop testers which are ok for engine batteries but not suitable for use on leisure batteries, more likely to damage the batteries than tell you anything useful.

Subscribers  do not see these advertisements

 
David and Sally said:
Replace them just to be safe.
Click to expand...
They are booked in to be replaced in 3 months.

My main concern is can I use the van safely in the meantime ?

If I disconnect the leisure batteries, can I still connect to EHU?

If no batteries but EHU will my fridge still work on gas?
Will taps, water heater, water pump work?
 
Battery removal isn't an easy task

Can I just disconnect one negative from the battery instead ?

Would it be safe, having disconnected the battery, as above, to plug the EHU lead again to a) see if any of the 12v works independently of a battery & b) provide some 240v
 
You wouldn't catch me sleeping in a van with batteries gassing off whether the power has been disconnected or not! Get them out and replace now not in 3 months time!
 
Usually your 12v circuits Need a battery for power. EHU charges the battery and the battery gives a smooth 12V supply.
Bubbling and hot battery - get it out immediately. If you are not physically able then if you are buying a battery from a shop/Halfrauds they will usually lift out and drop in (if they want the sale!)

Subscribers  do not see these advertisements

 
Jev88 said:
Bubbling and hot battery - get it out immediately. If you are not physically able then if you are buying a battery from a shop/Halfrauds they will usually lift out and drop in
Click to expand...
Mixed message there
I appreciate you're trying to help this humpty.

Getting them out is understandably preferable but if it's safe to leave them in situ until I can get to a battery shop, why is it not safe to leave them in place longer.
 
Mixed messages? I will try to be unambiguous.
Langtoftlad said:
My main concern is can I use the van safely in the meantime ?
Click to expand...
No.

Lead acid batteries can give off hydrogen which has no smell and is highly flammable.
IMG_0591.jpeg

Your CO alarm seems to have detected hydrogen which would only happen if there was a problem. If you can’t remove them I would disconnect both batteries and avoid any charging.
 
Could you not get a mobile mechanic to come to the van to remove and replace them?
 
If you have a solar panel then at least the leisure battery and possibly also the starter battery will continue to be charged, do you have an isolation switch before your solar controller?
 
There should be a big fuse very near the leisure batteries, which will isolate them if you remove it. That will stop charging from the mains, solar and also from the alternator when the engine is running. However all the habitation electrics need 12V so probably nothing will work.

Anker make all different sizes of 'Power Bank'. but if your 'Anker Powerbank' is quite large, the type with built-in inverter and mains sockets, then it will also have a round 12V socket. You could possibly rig up something by connecting it to the wires from the leisure battery, to run the basic 12V habitation circuits, which would be OK for a couple of nights.

One of those CBE fuseboxes will have a couple of large bolts which take the power from the leisure battery, and you could connect the 12V positive and the negative to them. However you must make sure the large leisure battery fuse is definitely removed to avoid putting charge into the leisure battery inadvertently.

Subscribers  do not see these advertisements

 
Pausim said:
Your CO alarm seems to have detected hydrogen which would only happen if there was a problem. If you can’t remove them I would disconnect both batteries and avoid any charging.
Click to expand...
Just been out to the van again, co alarm isn't going off.
I can't hear any simmering anymore
Both batteries have been completely disconnected, nothing attached to any of the four terminal posts
I did have another go at lifting them out, but they catch on the lip of the bed frame. So without dismantling the whole bed frame [if that's even possible] I don't see how they are coming out without a large crowbar.
Itsmcb said:
Could you not get a mobile mechanic to come to the van to remove and replace them?
Click to expand...
I'd rather not as replacements are already scheduled in 12 weeks - I have no firm plans to use it before then.
Itsmcb said:
If you have a solar panel then at least the leisure battery and possibly also the starter battery will continue to be charged, do you have an isolation switch before your solar controller?
Click to expand...
The leisure batteries are now completely isolated. I believe I've removed the solar panel fuse.
autorouter said:
Anker make all different sizes of 'Power Bank'. but if your 'Anker Powerbank' is quite large, the type with built-in inverter and mains sockets, then it will also have a round 12V socket. You could possibly rig up something by connecting it to the wires from the leisure battery, to run the basic 12V habitation circuits, which would be OK for a couple of nights.
Click to expand...
Leisure batteries now isolated.
The batteries were the issue.

autorouter said:
One of those CBE fuseboxes will have a couple of large bolts which take the power from the leisure battery, and you could connect the 12V positive and the negative to them. However you must make sure the large leisure battery fuse is definitely removed to avoid putting charge into the leisure battery inadvertently.
Click to expand...
I think that's a bit above my skill level & pay grade. I'd rather not start dismantling fuseboxes.
The leisure batteries are completely isolated.
 
Given that my two leisure batteries are completely isolated now

What will happen if I plug the EHU back in?
  1. Bang 🔥
  2. Nothing
  3. I'll have 230v mains but no 12v
  4. I'll have 230v mains and maybe some 12v
 
Most likely 3, possibly 4. Depends on the mains charger. Most chargers will just not output anything if they can't see a battery. Some chargers go into 'Power Supply Mode', where they output a constant voltage, about 13.8V, which is fine for running the habitation circuits. Worth a try.

An alternative to the bodge that I suggested in post#15 is to get/make a cable with a round 12V plug on both ends, plug one plug into the Anker 12V socket, and the other end into a 12V socket somewhere in the motorhome. You would probably be able to run a few items from that. Lights, fridge control board, maybe heater controls.

The limitation would be that the socket would have a fuse, maybe 10A, which would limit the power you could use by that method, but it's better than nothing, and probably not too difficult to do. Best to keep a few spare fuses handy, you're quite likely to blow one or two while trying to see what works.
 
autorouter said:
An alternative to the bodge that I suggested in post#15 is to get/make a cable with a round 12V plug on both ends, plug one plug into the Anker 12V socket, and the other end into a 12V socket somewhere in the motorhome. You would probably be able to run a few items from that. Lights, fridge control board, maybe heater controls.
Click to expand...
Would that work?
How & why?
You mean something like this
61lZVJhXeML._AC_SL1000_.jpg
Click to expand...
It's cheap enough to give it a whirl.
Edit - I apparently bought one last year according to Amazon, I wonder where I put it :unsure:. I was experimenting with the powerbank to see if the 12v output would charge my leisure batteries [it didn't]

If only as an experiment, to satisfy my curiosity.
I do have 2 12v sockets to try

Thank you


When you mention socket fuse blowing - do you mean on the Anker Powerbank - I don't think it has fuses as such but trip which can be reset
 
Last edited:
This site contains affiliate links for which MHF may be compensated.
If you remove the + lead from the leisure batteries and wrap it in plastic bags (a good thick wrapping and secure with tape so no way it can connect to + of battery or -of battery or chassis/ any metal ,put fuses back 12 & 240 will probably work fine Be certain gas from batteries has cleared before lighting /switching ANYTHING ON OR DISSCONECTING A BATTERY LEAD couple of days with battery locker + doors and windows open

Subscribers  do not see these advertisements

 
Are you able to get a cheap / second hand 12v lead acid battery to put in the circuit. It doesn’t have to be big capacity. You could then run ehu without any worries, have a little bit of a bank and use the anker to run the charger and 240. It’s what I would consider doing in your position.
 
Cush said:
Are you able to get a cheap / second hand 12v lead acid battery to put in the circuit. It doesn’t have to be big capacity. You could then run ehu without any worries, have a little bit of a bank and use the anker to run the charger and 240. It’s what I would consider doing in your position.
Click to expand...
It's a good idea but I'd need a new battery box [ I can't actually get the old batteries out - I know it sounds nuts, but there we are], wiring etc which all becomes too much hassle for just 12 weeks... and no trips planned this year.

I'll try plugging in the EHU and see what, if anything, happens.
and I'll try autorouter idea of plugging in my powerbank into the 12v circuit.
 
Be very aware cooked batteries are nasty to deal with. They stop gassing off after a few hours of the power being removed. What you are left with is a heavy plastic box of super concentrated acid in it. Just moving it again can cause it to start gassing again.
What bothers me with some van conversions is that getting the battery out involves dismantling furniture. Great till you need the battery out in a hurry
 
Langtoftlad said:
It's a good idea but I'd need a new battery box [ I can't actually get the old batteries out - I know it sounds nuts, but there we are], wiring etc which all becomes too much hassle for just 12 weeks... and no trips planned this year.

I'll try plugging in the EHU and see what, if anything, happens.
and I'll try autorouter idea of plugging in my powerbank into the 12v circuit.
Click to expand...
I have always rated auto’s advice. The anker 12v to 12v sounds like it’s worth having a go. If you need to and if you do plug in ehu, make sure you have the terminal ends of the wires well wrapped and insulated as mentioned. Good luck and keep well ventilated.

Subscribers  do not see these advertisements

 
Langtoftlad said:
Given that my two leisure batteries are completely isolated now

What will happen if I plug the EHU back in?
Click to expand...

Whatever you do, make sure that the ends of tye battery cables are insulated and can’t short to earth.

Ian
 
Langtoftlad said:
Would that work?
How & why?
Click to expand...
The MH 12V socket will be connected to the common power distribution point inside the fusebox. Normally the amps flows out from the fusebox, but if there's no supply from the leisure battery, the amps can flow the other way, back into the fusebox.

There will be a fuse in the fusebox that will limit how much amps can flow in that way. Probably 10A or so. Looking at that cable from Amazon in your picture, there are also fuses in each of the round 12V plugs. They will be the glass tube type, so try to get some spares of those if you can. Just unscrew the tip carefully, or you'll be hunting for the bits that get projected out by the spring inside. The maximum fuse value should be written on the 12V plugs, probably 10A or 7A.

If you draw too many amps, a fuse will blow, whichever is the lowest amp value. If they are all the same it's pot luck. I think the thing most likely to blow the fuse is the water pump, so try that to see if it's OK.
 
So that was a surprise.

I've disconnected the leisure batteries entirely, just four completely bare terminals.
I've bagged & taped the connectors.

I plugged in the EHU - no bang (y)

Yay, I have 240v - no surprise there
but
I also have 12v 😲...

Control panel fires up ✅
Test the fridge ✅
Truma boiler ✅
Water pump ✅
Lights ✅

Unfortunately, autorouter idea of plugging in 12v from my Powerbank didn't work.

But at least I have a no leisure battery workaround as I can use my Anker as a pseudo EHU
(no idea how long it might last given it's not charging any batteries)
 
Be careful if you have a 12 volt tv with no battery in the system as the battery acts as a stabiliser if the voltage spikes you might loose the tv

Subscribers  do not see these advertisements

 

Join us or log in to post a reply.

To join in you must be a member of MotorhomeFun

Join MotorhomeFun

Join us, it quick and easy!

Join us

Log in

Already a member? Log in here.

Latest journal entries

Back
Top