Testing your battery

I'm in a similar situation, had my 110 ah battery 4 years, and it doesn't seem to be lasting/holding charge as long as it did. I can check the voltage, which I know is related to charge level, but how can I tell how many amp hours there are left and if its failing? Can I test amperage?Thanks for any help.

Hi Andy,

  Not sure why you want to check your battery unless you have had problems or it is an old one but you cannot do a proper test with a meter as you need to place it under load and do a drop test on it and that will then tell you if it is OK. The only thing you can check with your meter is the voltag, if it falls below 12volts quickly after a charge I would say it is knackered and You need a replacement but if you take it along to Halfords or your local caravan service dealer they will check it out for you free of charge and let you know it's condition. The last thing I would add is to make sure your battery charger in the van is working correctly. Whilst charging the battery the battery voltage should be around 13.2 volts, hope this helps.!

Hi the battery seems absolutely fine I just wanted to know how to test the battery sorted I would know 

Take care 

Andy 

So if I put the kettle on then the battery would be load bearing ?

Take care 

Andy 

That would work only if it is a 12v kettle (unlikely) or you are using a normal 240v kettle from an inverter running on 12v (even more unlikely!).  Most of the domestic equipment in your caravan will be supplied with "house" electricity through the EHU cable.  The battery is 12v DC and runs things such as (some) lights, radio, toilet flush. Only something like a motor mover will put enough load on it to find out how good it is, and then the battery might fail with the 'van in an inconvenient spot.

Testing is actually dangerous so get someone who knows what they are doing to take the risk.  Basicly they connect the battery away from the van to a device that measures the voltage while puting a great big heater element across it as well.  Lots of power goes to the heater and the voltage will drop.  How much it drops and how well it recovers tells the condition of the battery.  Not surprisingly, a battery can explode when doing this sort of test, so watch from a distance.

Hmm I think I'll take you advise and take the battery to be tested 

Take care 

Andy 

 ..... You need a replacement but if you take it along to Halfords or your local caravan service dealer they will check it out for you free of charge and let you know it's condition. ...

I'd imagine you'd get a blank look at Halfords if you asked them to drop test a battery. And years ago when I bought a battery from a local caravan dealer and had problems with it, they had to send it away to be tested.

You need a proper old fashioned auto electrician 

 ..... You need a replacement but if you take it along to Halfords or your local caravan service dealer they will check it out for you free of charge and let you know it's condition. ...

I'd imagine you'd get a blank look at Halfords if you asked them to drop test a battery. And years ago when I bought a battery from a local caravan dealer and had problems with it, they had to send it away to be tested.

You need a proper old fashioned auto electrician 

I agree, MM. Drop testing / heavy discharge seems to have gone out of fashion but is the only test worth doing to prove the state of the battery.

I imagine Halfords would drop test it by dropping it from a great height!

Thanks for everyone's help 

Take care 

Andy 

Andy you don't say if you have a battery panel in the van - I came back to caravanning a few years ago from the era when there was almost no onboard 12 v!  It took a while to get used to the control panel that showed the voltage etc.  Now I find it fascinating to watch the battery when not on electric hook up and using solar and inverter, but seldom check the battery now when using EHU.  My battery was new last year and i have just checked it after an extended period away all on EHU and its in great shape.