Battery size

[Jack_374316106]

I was about to buy a new battery of 113 amp/hr.

I have now been told by someone in the trade that I should not buy anything other than an 85amp/hr. Apparently the charging systems on caravans will not fully charge the larger capacity battery.

Has anyone got any informed opinions?

 

[James_374408700]

Jack,

As far as I am aware it has nothing to do with the amp hour of the batt.

Its the voltage thats needed to fully charge........I think!

 

[Gabsgrandad]

Hi, I think your man in the trade is a little mistaken, he is saying that the charger on a caravan won't fully charge a 113 amp battery, he should also be telling you that it won't fully charge an 85 amp one either.So read the following bit of information, and go ahead and buy your 113amp. Being sure that it will fit your battery box, and also remembering they are also considerably heavier.

TWO-STAGE BATTERY CHARGER

For many years caravan manufacturers have been not installing the correct charging equipment to take care of the excellent but expensive leisure style batteries subsequently installed by the caravan owner, after delivery.

What has been fitted by almost every manufacturer to date has been a device best described as a 12 volt DC supply - which has been erroneously called a battery charger. In similar vein, an EEC directive has stated that such a device should not put out more than 13.8 volts - and that's where the confusion has occurred.

For 13.8 volts is also what is termed a float voltage for a battery charger - which any battery manufacturer will tell you, should kick-off the charging process at a minimum of 14.2 volts if the battery is well discharged - or the battery will never be fully charged. If that is done continuously over a comparatively short period, irreparable damage will be done to that expensive leisure battery.

Another reason for not towing the line in their choice of "charger" is something which haunts every manufacturer - the bottom line. Good chargers should start at about 14.5 volts and cut back automatically to the 13.8 float voltage, as the internal voltage of the battery rises - and are known as staged chargers, which cost more.

So to get a fully charged caravan battery you have to use an external charger occasionally, preferably a staged one.

 

[xtrailman]

There is an advantage to the lower charging rate, the battery should not need topping up so often, this is usfull when on mains electric.

Also i would recommened buying the 110 a/h version if you have a motor mover.

Note the car will charge the van battery (if your towbar is wired for it), at a higher voltage around 14.5 volt.

 

[Jack_374316106]

Hi, I think your man in the trade is a little mistaken, he is saying that the charger on a caravan won't fully charge a 113 amp battery, he should also be telling you that it won't fully charge an 85 amp one either.So read the following bit of information, and go ahead and buy your 113amp. Being sure that it will fit your battery box, and also remembering they are also considerably heavier.

TWO-STAGE BATTERY CHARGER

For many years caravan manufacturers have been not installing the correct charging equipment to take care of the excellent but expensive leisure style batteries subsequently installed by the caravan owner, after delivery.

What has been fitted by almost every manufacturer to date has been a device best described as a 12 volt DC supply - which has been erroneously called a battery charger. In similar vein, an EEC directive has stated that such a device should not put out more than 13.8 volts - and that's where the confusion has occurred.

For 13.8 volts is also what is termed a float voltage for a battery charger - which any battery manufacturer will tell you, should kick-off the charging process at a minimum of 14.2 volts if the battery is well discharged - or the battery will never be fully charged. If that is done continuously over a comparatively short period, irreparable damage will be done to that expensive leisure battery.

Another reason for not towing the line in their choice of "charger" is something which haunts every manufacturer - the bottom line. Good chargers should start at about 14.5 volts and cut back automatically to the 13.8 float voltage, as the internal voltage of the battery rises - and are known as staged chargers, which cost more.

So to get a fully charged caravan battery you have to use an external charger occasionally, preferably a staged one.

Thank you, that was most informative.

Regards Jack

Ps thanks also to Practical Caravan for such a usefull site.

 

[Jack_374316106]

Jack,

As far as I am aware it has nothing to do with the amp hour of the batt.

Its the voltage thats needed to fully charge........I think!

Thank you.

 

[Jack_374316106]

There is an advantage to the lower charging rate, the battery should not need topping up so often, this is usfull when on mains electric.

Also i would recommened buying the 110 a/h version if you have a motor mover.

Note the car will charge the van battery (if your towbar is wired for it), at a higher voltage around 14.5 volt.

Thank you. I will take the battery off the caravan as it goes into storage after every trip out.

 

[Guest]

There is an advantage to the lower charging rate, the battery should not need topping up so often, this is usfull when on mains electric.

Also i would recommened buying the 110 a/h version if you have a motor mover.

Note the car will charge the van battery (if your towbar is wired for it), at a higher voltage around 14.5 volt.

Peter is spot on. I have been throwing away a battery every year because the item has never been kept up to charge properly. This year I bought a 113 amphour with a 3 year guanantee locally so I had a chance of some comeback. On removing the duff one of only 12 months old, bought from the original caravan dealer hundreds of miles away, I was able to recover it with a very large and expensive deep cycle leasure battery charger but that still took 36 hours. I shall now borrow that charger twice per year and trickle charge once a month during the winter storage time. Trickle charging is all you get from an ordinary car battery charger. Snag is that with a Tracker fitted to most big expensive vans you need to inform the Security people before and after dis/connecting the battery. We should lobby manufactureers to do better.