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Batteries that seemed ok, were not.


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As we have documented before, most of the chargers we get show clear signs of being overloaded by poor batteries, an overlarge battery bank or both.

When we report our finding and suggest the batteries will very quickly damage the repaired charger, we are often met with a comment along the lines that the batteries are fine and don't need changing.

This puts us in difficult situation, if we go ahead and repair the charger, we know there is a very high chance we will be contacted very soon after to say "the charger has failed again, you didn't do the repair properly".

Sometimes we decline to tender for the repair, as it is less long term hassle.



To counter that, we also regularly, get a response back to say the batteries turned out to be poor and have been replaced.



The feedback today is slightly different, because it talks about one battery down to 80% on efficiency, a failed battery in our opinion. However, the second battery 'appeared ok', it held it's voltage when 'idle', but as soon as any load was applied it dropped like a stone.

The email goes :


"A quick note to let you know that the EBL has arrived safely. I haven't had a chance to reinstall it yet: hopefully I can do that over the weekend.

Also thought you might be interested to know that your assertion that the root problem was likely to be the batteries appears to be correct. I have bought 2 new Varta 75Ah batteries to replace my Alphalines anyway, but have also checked my original batteries. One was still in reasonably good shape, being approximately 80% efficient.

The other wasn't, it held voltage when not under load, but putting a couple of amps of load on it caused the voltage to drop below 11.6v.

Many thanks for all your help,




Just because a battery doesn't lose voltage when idle, doesn't mean it isn't exhausted.


More info on how Habitation batteries work here : http://www.aandncaravanservices.co.uk/how-does-a-battery-work.php



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Serendipitous post!


Just returned after a 10 days away in our motorhome. After we'd been away for 3 days (wildcamping - staying 1 night at each location before moving on) we got up and found the leisure battery to be flat (lights dim, water pump running slow), nothing appeared to have been left on overnight (other than what we normally leave on (fridge)) battery voltage was 10.7v. current draw was (according to the van electrics) 0.2-0.4A


Moved on to our next location and the same thing happened. Went to a site for a night so we could hook-up and fully charge the battery. Next night wildcamping the battery voltage was again well down in the morning.


Since we've come home I fully charged the battery (12.9V no load, 12.75 V load (habitation lights on)) then disconnected it and put a load on it (55W headlamp bulb ~ 4.6A) After 3 hours the battery voltage was down to 10.5V when loaded, 12.5V no load


I've never measured it but from our useage I'd guess we've never discharged the battery more than 20% - we mainly wildcamp and lighting, fridge and waterpump are our main consumers.


The battery is a 110A Lion battery and was installed in 2014 under warranty*


Since it looks like we're going to buy a new battery I'd be very interested to see what you think about the (little publicised) NCC verified leisure battery scheme as their data seems to suggest some of the batteries can do 2000+ discharge cycles www.thencc.org.uk/our_schemes/ncc_verified_leisure_battery_scheme.aspx


* One of the few occasions where the battery wasn't the issue - the van supplier replaced the battery after we experienced an electrical fault (at the time I argued that it wasn't a battery issue as I had done some fairly extensive testing before contacting them) and 2 weeks after we got the van back they had to replace the solar panel regulator when the same fault re-occurred under identical circumstances.



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