Leisure battery not charging

[AlBundy]

I bought a new leisure battery in June, installed it alongside a new Sargent EC155 power control unit, and wired it up correctly, plus added a new fridge and wired directly to the battery as per instructions.

It was all working fine, charging from the alternator and charging from the electrical hookup, but after a few weeks in the body shop, the battery has now stopped charging completely.

Any suggestions as to what might be causing this as I don't want to install a new one until I can figure out why it broke. The van electrics were switched off while having the body work done, and it was only for about a month, so not a very long time to be not running.

Any ideas welcome.

[mioba]

Could be the body shop fried the electrics when doing welding - assuming they done welding.
Checked the fuses to the unit?

[AlBundy]

Fuses fine, but the charging wire to the battery from the PCU had come loose, possibly when they disconnected it. Have fixed and now plugged back in to charge.

Keeping my fingers crossed it works, hopefully no long term damage.

[AlBundy]

Update, after a night charging the battery looks like its toast. It registers fully charged when plugged in and charging, but completely flat when unplugged.

Limited research suggested that it could have been caused by welding work if the leisure battery was not disconnected.

I can't think of any other reason, but don't want to start accusing the body shop off damaging it if this couldn't have caused it.

[SyncroMatt]

Rule number one of welding club.....

Disconnect the battery....

[cobblers]

Welding will 100% not have damaged the leisure battery. Being left completely discharged for a length of time is what has damaged the battery, so you need to look into why it went flat - there maybe be some constant load that has drained it over time. Unless it was faulty from new, a battery (unconnected) should hold a decent charge for 12 months or more.


If you have a "Smart" split charge relay, welding could potentially have damaged this which is why the battery isn't charging, but I'll say it again - welding on the vehicle can't and won't damage a lead acid battery!

[AlBundy]

Thank you for the replies.

It is possible that there is a constant discharge, but there are only two connections, one to the EC155 PCU, and one to the fridge, which was switched off.

I will need to find a way to test if something is drawing power when all is switched off.

The van was sent into the body shop with full charge in the leisure battery, and in there for about 6 weeks, so not really long enough to completely destroy the battery, which is why I am looking for another explanation.

I expect after owning this van for a few years I will be an expert, but for now am really valuing your guidance.

[Mocki]

Ok, so, do you have a multimeter ?
Dont worry if you dont , you can simply use a bulb and a couple of bits of wire

Disconnect the negative off the battery , leave the positive connected
Take your multimeter set to amps ( or 21w indicator bulb and two bits of wire ) and connect tween the negative pole of the battery and the negative lead you have disconnected from the battery .
With everything switched off there should be a reading of zero amps being drawn ( or the bulb will not light at all )
Switch on the fridge , you will see a meter reading of power being taken ( or the bulb will glow )

Now if with everything switched off there is no power being drawn , the battery is self discharging ( lead acid batteries do self discharge , not at a greater rate , and certainly not enough to cause damage in 6 weeks )

Now bearing in mind that you have already told us the battery has been fully discharged , it’s damaged , without doubt, to a degree , but maybe not completely FuBaR’d .

You should fully recharge this battery with a good quality mains battery charger , and once fully charged , let it sit disconnected completely for 12 hours and take a voltage reading , then let it sit a further 24 hours completely disconnected from anything and take another reading . It should not have a difference of more than 0.5v between the first reading and the second reading if the battery is to survive reliably

A fully charged lead acid leisure battery should hold a voltage of 12.6v minimum

[AlBundy]

This is really daft, but after testing, I found a fuse blown hidden at the back of a cupboard that stopped the leisure battery charging. I have no excuse, i fitted the electrics, I just forgot about it on my wiring diagram.

Thank you for your help, I am learning a huge amount from this forum, really appreciate the help from wiser heads.

[AlBundy]

Update on this, the same fuse keeps blowing. It had a 20amp fuse when installed so I have kept replacing like for like, but it has going through 4 now.

It seems to be happening when charging of the split charger which isn't ideal as I need it to do that without breaking.

Any suggestions for why it might be doing this, and any recommendations for how to fix?

Al

[Oldiebut goodie]

The leisure battery is tooo loow so is trying to charge at a rate higher than the wiring and fuse can take. Charge the leisure up off the van system first (as advised earlier.)

[ZsZ]

I had luck repairing dead flat batteries with cheap pulse charger from aliexpress
This kind:
https://a.aliexpress.com/_EyWUMnf

I would try to charge the battery first out of the van. If it is dead, then replace it. If it keeps blowing fuses even with a new battery, then the charger (or alternator) might be bad.

[AlBundy]

Sorry, I maybe didn't explain, the leisure battery is fully charged and fine, I charged it fully using an external charger, it reads 12.94 volts and is holding that.

The issue is that the fuse between the split charger in the Sargent EC155 PCU keeps blowing. Does that make sense?

[ZsZ]

OK, then there is possibly a short somewhere.
Either in the wiring or in the controller unit itself