Leisure battery not holding charge - 2 years old!

[RobPeel]

Morning Funsters. Had a new leisure battery fitted on 10th Jan 23 - Numax 105Ah. From fully charged yesterday at 13.7v, its dropped to 8.1v. Nothing at all switched on (except maybe tracker & VanBitz alarm. Is it goosed? Should I go back to dealer or move on to lithium? Starter battery new 18 months ago. Can I mix lithium and agm please? Comments appreciated.
Cheers Rob

 

[Manic]

Most battery come with 3-5 year warranty, so go back to dealer
I had one fail in 4 1/2 months and that was changed as it had a 5 year warranty.

 

[Kannon Fodda]

Was the battery actually fully charged? 13.7V shows the charger is on and trying to put in current. You need to look at the voltage when it's been at rest ( no current in or out) for at least 30 minutes. 12.8V would be a 100% charge on AGM.

But batteries degrade with each charge / discharge and that will accelerate if your discharge is more than 50%. 8.1% is more than flat so your battery has died . You might get it replaced on warranty but if they say it's failed through misuse (50% etc) ...

Yes it may be time to look at lithium. Those who have lithium for leisure still have lead acid for the starter. Just have to make sure it's installed properly.

 

[Carpmart]

Sounds goosed!

TBH, you can kill a new FLA with even a few too deep discharge cycles!

 

[Lenny HB]

Your alarm & tracker will be connected to the starter battery.

Sounds like the hab battery has had it.

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[Richard n Ann]

Before you buy the new one just clip a clamp meter round the positive wires on the battery terminal and see if anything unexpected is draining it. Otherwise in 2 years you'll be back to square one

 

[RobPeel]

Thanks all. First time it has seriously dropped (2 weeks out of 2 year warranty!) - I normally have it on ehu via a timer to maintain levels & a bit of heat.

 

[Pausim]

Numax AGM needs 14.4V to charge properly. Has it been getting this? If not it may have become sulphated. People worry about charging lithium batteries but AGM are far more fussy and easily damaged.

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With AGM products becoming more widespread in their use, knowing when you can or should use one and how to look after it properly is all the more important - our guide is here to help.

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[RobPeel]

Well, from being 8.7v at 9.30 this morning, I drove to the dealer about 20 miles away. They tested the battery 100% health/100% state of charge - 12.7v!!. After taking the drivers seat out of course - no easy task. Battery 2 weeks out of warranty but they agreed to send it back to Numax for testing. Numax DC25MF C20 850A if that means anything to you tecno wizards. Dometic battery charger CA-360 goes up to 14.7v output. So no leisure battery for a week (interesting radio/satnav/reverse camera must be wired to leisure battery). Cheers. Rob

 

[AdrianChen]

Well, from being 8.7v at 9.30 this morning, I drove to the dealer about 20 miles away. They tested the battery 100% health/100% state of charge - 12.7v!!. After taking the drivers seat out of course - no easy task. Battery 2 weeks out of warranty but they agreed to send it back to Numax for testing. Numax DC25MF C20 850A if that means anything to you tecno wizards. Dometic battery charger CA-360 goes up to 14.7v output. So no leisure battery for a week (interesting radio/satnav/reverse camera must be wired to leisure battery). Cheers. Rob

OK well that is a pretty standard wet lead acid leisure battery, so with 14.7v from the charger (AGM setting?) it may have been gassing a bit. Not sure what tester the dealer used, but I guess Numax will test it properly in any case.

The charger only has three charge profiles, Lead starter, lead Gel and AGM, then later they refer to Lead starter, AGM, and Maintenance Free. To me they don't look perfect for a leisure battery, but the Starter one at 14.4v with float at 13.8 seems most appropriate (float seems high to me though)....

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