One for electronic boys

[bugman]

Hello,
The cat has a three battery setup. Two batteries - one for each motor connected via isolater switch. The third "house" battery also has an isolater switch enabling it to be used in conjunction with the other two, So you can have 1 battery, 2 batteries or 3 batteries.
I've finally got a storage shed big enough for the cat and have her roofed for the first time. Anyway hooked a CNet trickle charger to the system to stop the batteries from dying.
To charge them all I'd have to have both isolaters switches open - correct?
Brett

[inveratta]

I looked at this a while ago for 2 batts and isolator...was advised not to charge both at the same time as the final charge level would be that of the lower functioning battery...I guess three batts would be the same?

[aussiebasser]

Inveratta is correct. If you charge them all together they will assume the condition of the weakest battery. Better to buy 3 cheap Ctek trickle chargers and have one on each battery.

[bugman]

OK - that answers the question.
Thanks

[rtp1984]

Following that rule, (I am not disputing it), on a boat that has only 1 outboard, that you would assume has only one charging system, would you end up at the same state of only as good as the weakest battery?
if so, j would assume there is no real benefit to charging you batteries seperatly? For as soon as you have started the donk the first time, it is probably at the lowest batteries level?

is this right??

Thanks
rob

[scottar]

To charge all three you will need to have the battery switches all switched on (typically what is referred to as closed, not open) so they are all connected together. The If one of your batteries is down the charger will just keep charging until the voltage comes up (if it ever does). It's not a great situation as the boat will be "live". My rig has a small maintenance charger permanently wired and the batteries are diode fed so they can be charged with the isolators off and there is no interaction between them but the charge voltage they see will be 0.6 of a volt lower. Not sure it would work with a C-Tek charger though with their smarts - wouldn't cost too much to try though.