Auxiliary Battery Charging Questions.

[paulrichardson]

Hi Guys,

Firstly, I wondered how you decide how big a Battery Charger you need for the Auxiliary Battery on a Camper Van.

Ideally it would fully recharge a 100amp battery during a single night on a hook up.

I would love to know the magic formula.

Secondly, are the "Intelligent" Battery to Battery Chargers worth the money, surely a simple Split Charge Relay will put as much charge in the Auxiliary Battery as the Alternator can produce?

Hope my questions aren't too stupid.

Looking forward to hearing from you.

Regards,

Paul

[Aardvark]

Definitely not stupid questions. If you have some sort of split charge setup you won't need another seperate charger for the overnight because you will have both batteries in good shape from driving. Some smart chargers are very good at recharging quickly if that is what you need. Some of the top level ones have a "conditioning" phase that you can use occasionally to give it a really good kicking to blow the sulphates off the plates. An ordinary one will top you up overnight well enough. My personal favourite is the Adverc charge regulator fitted in place of the standard regulator in your alternator. It runs the alternator flat out until the battery (or batteries) are well up before cutting back the charge. A normal regulator will start to drop its output as soon as the battery voltage starts to rise and therefore takes much longer to fully charge a battery. Most vehicles that do a lot of stop/start work benefit from these as they don't stay running long enough to fully recharge the battery after the initial load from the starter. Add headlamps and a heater fan, etc. and you can see how at the end of the day a battery has a hard time of it the following morning.