Charging Batteries In Boat

[smartbuffboy]

I was told somewhere that I should not charge either of my batteries while they are in the engine and hooked up to the electrical box (Twin Rotax 85hp engines, one battery for each engine).

I recently purchased a Blue Sea Systems battery switch that stops the flow of current to both batteries by switching to "off". In doing this, does that mean that I could charge the batteries inside the boat now? A ground cable connects the two batteries, will I need to disconnect that as well, or just turn off the switch?

Or, is it not true and you CAN actually charge them while connected to the electrical systems (in boat)?

Thanks.
Richard.

 

[JPX]

I suppose officially by using a cutoff switch, you are isolating the battery from the MPEM (computer). And therefore you could charge the battery without actually removing the cables. Electrical it seems to make sense.

I don't like it though. Easier done with a PWC than a boat I will admit, but I prefer to completely remove the battery from the boat while charging during storage. That way if there are any fumes built up during charge, it does not accumulate to dangerous levels in the confined space of the hull. And I prefer not to have the battery connected to the PWC at all when charging - even if it is just a ground.

 

[scarfie]

A 20 + gallon fuel tank and sparks from a charging battery in a confined space do not play nice. Don't ruin your day...take the battery out to charge it.

 

[texasmojo]

I turn off the power at the battery switch and leave the compartment doors open when i charge my battery inside my challenger. I also put the charger as far away as possible outside of the boat. I charge overnight at 2amps. And the charger stops when fully charged.

 

[imnothot02]

even a battery minder...?

 

[unclejay]

Battery Tender Waterproof

I have been using a Waterproof model Battery Tender brand name for the entire 13 year life of my Speedster with no problems. It uses a very low trickle charge and no sparks due to the waterproof design. it is bolted to the firewall with a lead running out the vent hole and external 110v (you for sure dont want to have the 110v plug inside the boat). Speedster batteries are nearly impossible to remove or isolate.