8.75V (1 Viewer)

[DFMan]

Hi Folks,

That's the multimeter reading straight off the Leisure battery. I have read quite a few articles on leisure batteries but being a complete newbie I thought I had better post here to get some advice.

The battery is a
NUMAX LV26MF

Is there a point in rescuing it?

 

[Jim]

I think it as dead as a Norwegian Blue, but it might be worth having a go at it with a charger that conditions as well, some say they have them recovered them from such low voltages.

 

[DFMan]

@Jim Unfortunately I would have to buy a battery charger/conditioner as I don't have one. So it looks like it's going to be a new one. Are they reasonably straight forward to fit yourself?

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[tacr2man]

Yes , take of neg terminal first . Remove second terminal . remove battery holder, and fit new reverse order If you have solar make sure you disconnect solar first.

 

[autorouter]

You don't say why the leisure battery is discharged, but you need to know that often a flat battery is a symptom of problems elsewhere, either in the charging or consumer items. Keep an eye on the voltage of the new battery to make sure it doesn't go the way of the old one.

 

[DFMan]

@autorouter I have no clue on that as I have just bought the MH.

Has anyone got any recommendation regarding make and model?

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[irnbru]

Where about are you? Someonenearby might let you borrow their charger. If your anywhere near Bellshill you can borrow mine.

 

[DFMan]

I am in Lancashire.

 

[scotjimland]

I would say it's buggered.. technical term.. at that voltage at least one cell is probably dead or short circuit .. don't waste time or money trying to recover it.. even if you do, it will probably be damaged and never give the service you need ..

Make and model,

Tanya batteries will supply like for like.. https://www.tayna.co.uk/leisure-batteries/numax/lv26mf/

If you want to spend more look at Trojan who make traction batteries, these are designed for heavy use, as used on golf carts, mobility scooters etc
how much you should spend depends on how you camp, do you go on EHU a lot or not.. do you have solar.. who do you expect from a battery ?

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[DFMan]

@scotjimland I hope to reply on EHU less and less in the future as the idea of Aires(less available EHU than campsites) appeals to me. I don't have solar and I hope that it can take care of all the mobile devices, lights and a 12V TV and a MiFi device.

 

[scotjimland]

@scotjimland I hope to reply on EHU less and less in the future as the idea of Aires(less available EHU than campsites) appeals to me. I don't have solar and I hope that it can take care of all the mobile devices, lights and a 12V TV and a MiFi device.

In that case I suggest a new like for like battery and also look at the possibility of adding a second identical one, thereby doubling your capacity and length of stay off EHU.. see how you get on.. If needs be, after that consider a solar panel .. say 150watt to start , that will further extend the time you can be off grid..

Do you have space for another battery in the battery locker/box or close by ?

Bear in mind, if you are touring the battery will be recharged every day when you drive.. so may not need any more capacity

 

[irnbru]

Good advice your being given by scotjimland.
Depending on your battery type remember to only use your battery to around 50 percent and not use it til it’s flat or you will knacker it.

I’d definitely think on getting a 2nd battery or solar.

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[DFMan]

@scotjimland @irnbru The battery tray is 32cm by 32cm with a height allowance of 27cm so two batteries in the same place is out of the question. This is a shame as really like the setup scotjimland has suggested.

I do feel a little silly that I did not spot the potential problem as the 12V TV wouldn’t work after the engine was switched off when I test drove the van.

 

[tonyidle]

In that case I suggest a new like for like battery and also look at the possibility of adding a second identical one, thereby doubling your capacity and length of stay off EHU.. see how you get on.. If needs be, after that consider a solar panel .. say 150watt to start , that will further extend the time you can be off grid..

Do you have space for another battery in the battery locker/box or close by ?

Bear in mind, if you are touring the battery will be recharged every day when you drive.. so may not need any more capacity

That might be true but it takes a lot of miles to put even a small amount back without help from, for example, a battery-to-battery charger. Any serious off-site touring will need help from solar.

 

[DFMan]

All done. New battery ordered. Thank you all for your help.

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[meanders]

Make sure you properly vent the area around the battery before trying to connect or disconnect. They produce hydrogen and if it collects, a spark occurs and goes bang it can be spectacular.

Marquis did it to our leisure battery some years ago during a habitation check. Quite a mess as the battery case split throwing plastic shrapnel (if such a thing exists) everywhere and the engineer had a nasty cut on his face.

 

[DFMan]

@meanders The battery is stored externally. Do I still need to vent?

 

[davejen]

Yes, there should be a "hole" in the bottom of the battery box, to let the gasses escape. You may have a thin plastic tube coming from the top/side of battery this is a breather and should be pushed through the hole to let the gasses escape to the atmosphere.
Hope this helps,
Cheers, Dave

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[meanders]

@meanders The battery is stored externally. Do I still need to vent?

Always safest to do so. One habitation engineer I know uses a battery powered fan to force the hydrogen away once the cover is off the battery. Remember hydrogen rises in air. The pipe is not for draining it. It will drain out any electrolyte leaks but also allows some air in.

 

[maxi77]

Yes, there should be a "hole" in the bottom of the battery box, to let the gasses escape. You may have a thin plastic tube coming from the top/side of battery this is a breather and should be pushed through the hole to let the gasses escape to the atmosphere.
Hope this helps,
Cheers, Dave

As the prime gas we are concerned about is hydrogen, the lightest gas which will always rise a hole in the bottom has little utility.

 

[DFMan]

The battery has arrived! Do I need to switch off/ disconnect anything first before I disconnect the battery as described by @tacr2man ? Do I leave the battery to vent in the open first? If so for how long?

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[tonyidle]

As the prime gas we are concerned about is hydrogen, the lightest gas which will always rise a hole in the bottom has little utility.

Except for being the place to push the battery vent tube through.

 

[tacr2man]

@dfm If you havent been running anything from the "dead battery"
the chances of there being any gassing is minimal . Just disconnect the negative (earth lead ) , and retain it back out of the way . Then remove the pos lead and any fixings for the battery . Remove old battery , clean up while its out , and then fit new , reattach locating fixings . Then put on pos lead and secure . Then connect neg lead and secure fixing . Job Done , have a cup of tea I see from prev posts you don't have solar to bother about .

 

[Bailey58]

@dfm If you havent been running anything from the "dead battery"
the chances of there being any gassing is minimal . Just disconnect the negative (earth lead ) , and retain it back out of the way . Then remove the pos lead and any fixings for the battery . Remove old battery , clean up while its out , and then fit new , reattach locating fixings . Then put on pos lead and secure . Then connect neg lead and secure fixing . Job Done , have a cup of tea I see from prev posts you don't have solar to bother about .

And if he does have solar to think about (as I do when I get some answers before deciding what batteries I will buy)?

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[maxi77]

Except for being the place to push the battery vent tube through.

Which will not help unless you can make hydrogen proof joints

 

[tonyidle]

Which will not help unless you can make hydrogen proof joints

Or a very long tube. Maybe we're over-thinking this .

 

[tacr2man]

And if he does have solar to think about (as I do when I get some answers before deciding what batteries I will buy)?

If he did have solar , the solar needs isolating before disconnecting battery , as most solar regulators need the reference voltage of the batteries to control the voltage etc .

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[Allanm]

Do you have a multimeter? The battery may have been knacker^d anyway, but you need to know if is being charged.
Check the battery voltage after you have fitted it, then start the engine and see if the battery voltage rises. If it shows around 14v, your sorted, if the voltage doesn’t rise, you may have a fault in the split charge system.

Always safest to do so. One habitation engineer I know uses a battery powered fan to force the hydrogen away once the cover is off the battery. Remember hydrogen rises in air. The pipe is not for draining it. It will drain out any electrolyte leaks but also allows some air in.

Sounds very dangerous to me, even a battery powered fan can create sparks as it’s running. He should know better...