Another charger question

[Rhosyn Mor]

to all the electrical wizzo's,
in upgrading my charging system I want to add a 40 amp smart charger.
The kicker is that I have a 300amp gel cell battery bank, which I do not wish to replace. Am using a 10amp smart charger right now, but it does not have the remote sensor possiblities that the 40 amp does- is a 40 amp charger too big?, I know the gels have to be charged slowly. but is that more a voltage than an amp thing?
Thanks

[HorizonMarine]

The 40 amp smart charger will do fine with the 300 amp gel bank. The charger is only capable of putting out a max of 13% of total capacity, not a high number. It will have a way to set it up for gel batteries, which is important to set. Good luck.

[Rhosyn Mor]

THanks, you have confirmed my thoughts.

[Esprit Marine]

The gel batteries can generally be charged up to 30% of their rated capacity (i.e. 90A for 300 Ah). But as they are not wet batteries, they are very sensitive to high voltage, so you should ensure that your smart regulator is set to Gel mode (no equalisation), and limits the voltage to the maximum voltage advised by the battery manufacturer.

This maximum is dependent of the temperature, so with gel or AGM it is always better to have a temperature sensor, which generally comes as an option with your battery charger.