ric

I have a charger but can adjust Ampère and Volt.

What should I dial in to charge my battery and for how long?

thanks for any infos
ric

Spoons

Normally a "medium" charge rate overnight is sufficient unless the battery is very large or very flat (the JCB battery in my boat took 24 hours on a standard car charger from flat).

You can tell when the battery is fully charged as the amp meter on the charger will fall to zero.

A more scientific method is to divide battery rating by charge rate. Hyperthetically a 100 amp hour battery would take 10 hours at a charge rate of 10 amps, but it is not quite that simple. Firstly the battery may not be completely flat. Secondly the charge rate will gradually reduce as the battery becomes charged (due to higher internal resistance). Thirdly the charger produces a higher voltage than the battery is rated at (by around 15%). As a guide though, it should be between 12-24 hours (but look at the amp meter).

Hope that helps

Spoons

Spoons

oops

Forgot to mention...charger voltage should be around 14 to 15V (but may be indicated as 12V on the charger setting as this is the nominal rating of the battery).

Spoons

ric

Hello Spoons,

thanks a lot for your answer!

I now charged the battery for 12 hours at around 5Ampères. (the charger isn't stonger)

The charger can be set either to 12V or to 6V, I dialled in 12V.

I tried it in my car and I could start the car, but the starter wasn't too powerful.

So I guess, I will charge for another 12 hours, until the indicator on the charger falls to zero Ampères.

Thanks a lot for your information
greetings from Switzerland
ric