charging

[karl_5082018]

If i remove the battery from my caravan, can i pop it on charge with a standard car battery charger, or does it need a charger designed for leisure batteries?

 

[rob_jax]

Hi Karl,

Yes and No.

A leisure battery is simply a redesigned car battery - they both have sulfuric acid as the electrolyte, they both may have a GEL to reduce possible spillage, but the leisure battery has much thicker lead plates to resist "deep cycle discharges" and supply 10amps for long periods, whereas the (many) thin lead plates in a car battery help it to supply hundreds of amps to start the car.

So yes, you can use a simple car battery charger to recharge your battery, but unless the charger was designed to monitor the charge state of the battery, it will just keep on going past the fully charged point.

Charging beyond the fully charged point will blow off water and gases from the cells, and if the battery is "sealed for life" this may damage the battery.

So if you want to use a "dumb" car battery charger, you need to monitor the charge process yourself and turn off the charger once it is close to fully charged - about 80% to 90% charged is OK.

If the battery is not sealed for life, then you can always add distilled water if you do inadvertently overcharge the battery.

If you have a multi-stage "intelligent" charger then these can be left on all the time, and will take your battery to that perfect 100% charged state.

Robert

 

[karl_5082018]

hi thank you for your help, I'm running a mobile phone charger from the battery I use it as a tracking device while the van is in storage, as it has been a while since its been on a hook up thought I'd better put a bit of juice in the battery, would a 1watt solar panel I got keep it full charged while running the phone charger?

 

[rob_jax]

Hi Karl,

A 1 watt solar panel - not really - that will provide only around the self discharge current of the caravan leisure battery - for the few hours that the sun shines and nothing when night falls.

Battery self discharge is round 50mA to 100mA, plus your phone charger - say another 100mA - giving a drain current of around 150mA to 200mA, 24 hours a day.

If you are lucky, then you might get the equivalent of 4 hours of sun each day in the winter. So you need a solar panel that will supply the drain current multiplied by 6.

If we take a drain current of 150mA, this is a charge current of 900mA - multiplied by 12 volts is a requirement of 10 watts.

So I think you should look for a solar panel with a minimum rating of 10 watts but probalby 15 watt is a better match.

More is better, but above 25 watts you will need to fit a charge controller - which stops the solar panel overcharging the van battery and maintains the battery at 100% charge.

Also there may be periods of very bad weather, with little sun energy breaking through. So I would recommend a 25 or 35 watt solar panel and a charge controller, or hope for OK weather and get a 10 or 15 watt panel and no charge controller.

Robert

 

[lunar2000]

I agree with Robert (rob_jax).I have experience with a 15 watt solar panel, with charge control, bought at Maplins about 3 years ago and in service on a 120 amp leisure.

I have never in that time had to disconnect even thro' the storage period upto 6 months on some occassions. It is possible that because of the good weather over the last few years, I may have just been lucky.

The Maplin 15 watt solar panel costs about

 

[karl_5082018]

I agree with Robert (rob_jax).I have experience with a 15 watt solar panel, with charge control, bought at Maplins about 3 years ago and in service on a 120 amp leisure.

I have never in that time had to disconnect even thro' the storage period upto 6 months on some occassions. It is possible that because of the good weather over the last few years, I may have just been lucky.

The Maplin 15 watt solar panel costs about

 

[RayS]

Caravan Club have a very helpful leaflet - free download for members - on batteries. they say you should not allow teminal voltage of a leisure battery to go above 14.1v which it will do with a conventional charger. Sugguest charging in "bursts" ie charging until voltage reaches 14.1 (with charger connected) - switch off - leave for an hour and repeat until there is no time that the voltage does not get to 14.1 or above. The leaflet tells you why this is the way to do it.

 

[RogerL]

Get a fully automatic charger like the CTEK 3600. It'll charge safely up to 14.4v and can be left on indefinitely. It's a bit pricy though at

 

[Owain_5095786]

Get a fully automatic charger like the CTEK 3600. It'll charge safely up to 14.4v and can be left on indefinitely. It's a bit pricy though at