Club 80-90 Forums

My main van battery is struggling at the moment so for the last camp I disconnected the split charger, so that it was just the main battery that got charged during running.

This meant that by the end of the weekend the leisure battery was well and truly flat.... It has taken ages to charge back up again back at home.

My question is this (as I am not electrically minded), I have heard that some batteries are best periodically fully discharged and then recharged whereas some can be damaged if fully discharged.

I was just wondering if I risk harm to the leisure battery in letting it get totally flat, or does it do it good!

Thanks for any replies,

Paul.

lead acid should not be discharged, the vehicle battery particularly should be kept well charged, if you are not using it much then give it a charge with a battery charger overnight rather than relying on the alternator do do the work, you will rarely drive your van for several hours which is what a battery charger will do.

Don't know much about leisure batts but they are lead acid and so same applies, I think they have a system to limit the discharge so maybe won't suffer as much.

Normal car 'starter' batteries definitely DO NOT like to be heavily discharged, doing so will kill them pretty quickly. Proper leisure batteries are MORE tolerant and can be discharged to a higher degree and more often and generally recover with a good charge. However, even a true heavy discharge 'leisure' battery is BEST kept fully charged where possible ....

Where you might be getting confused is with lithium Ion and Nickel Cadmium (laptops/cameras/phones etc), which can suffer from 'memory effect' and DO benefit from FULL CYCLE charge and discharge for maximum battery life.

shaky wrote:I was just wondering if I risk harm to the leisure battery in letting it get totally flat, or does it do it good!

The answer to those two questions is: Yes, and definitely NOT.

It depends what you mean by "totally flat", I suppose. But, if you mean that the battery won't run anything and your lights go dim, then that is heavily OVER-discharged and will do damage to your battery. It's usually reckoned to be a bad idea to let a lead-acid battery go below 12.2V off load, or about 50% State of Charge.



If your starter battery is not charging properly, it would be worth investigating that first, to see if the battery is so heavily sulphated from persistent undercharging that it struggles to accept charge. Otherwise, it is worth checking that your alternator output is high enough (14.4V or so, at medium revs, on a fully charged battery) and that all the cables, including the earths, are as good as they can be.

James

Cheers all, I also had a quick chat with an electrician at work, and he says as you have that the leisure battery should not have suffered too much as it was a one off and to recharge it slowly so I've plugged it into a trickle charger and will leave it over the weekend. (I'm not going camping over a Bank holiday - far too busy). Note to self is that I should not let it happen again.... Main battery should not be allowed to discharge more than 50%, Leisure battery can go as low as 20% (Deep cycle) but don't make a habit of it!

I'll get the main battery sorted so that I can get them both charging properly, I've also been advised to invest in a proper 12v fridge rather than my coolbox fridge as they draw less current.

This is a good "noddy" article: http://www.campingandcaravanningclub.co ... e-battery/

Thanks again.

Just a thought but do you know if your leisure battery is a 'leisure battery'? The reason I'm asking is that we use a starter battery as a leisure battery. It's kept charged up and we only really use it for 12v LED lights, but I know it can't take the discharge that a proper leisure battery would.

Ian and Lins wrote:Just a thought but do you know if your leisure battery is a 'leisure battery'? The reason I'm asking is that we use a starter battery as a leisure battery. It's kept charged up and we only really use it for 12v LED lights, but I know it can't take the discharge that a proper leisure battery would.

Yes it is a pukka leisure battery, I did like you and used an ordinary battery until last year when there was a half price offer on leisure batteries a tour local motorsave. I got one of the last ones. (It was a faf finding a battery to give them in exchange, in the end I found an old one that had been left outside in my parents garden for years. The shop wasn't bothered other than I had to provide a replacement or pay a £10 surcharge).