Battery Charger Output

[friz]

I was reading a thread on one of the forums here about whether or not to spend $400 on a battery charger and it got me thinking. I am planning for two banks, starting and house. Looking at three house FLA batteries, 300-400 amh. Defender has a very good price on a Guest 30 amp 3 bank charger. I am assuming that it puts out 10 amps on each line? If correct, can I combine 2 lines from the charger to the house bank theoretically giving me a 20 amp charge available for the house bank? Or is the charger smart enough to distribute all 30 amps as needed even though one line is not connected?

Thanks, Friz

[ranger58sb]

Newer/better 3-bank chargers will put as much current on each "line" as each bank will accept -- within overall limits of the charger and the batteries. So no, it's not always necessarily a "10-amp-per-output" equation. No need to "combine 2 lines" to make that happen. IOW, the charger is indeed supposed to be "smart enough."

A 30A charger isn't necessarily optimum for a 400-Ah bank, and if you decide to add battery capacity later...

-Chris

[Stu Jackson]

You don't need a 3 bank charger.

What are ACRs, Combiners & Echo Chargers? (by Maine Sail) [scroll to the top]
http://forums.catalina.sailboatowner...d.php?p=742417 and Battery isolator / voltage regulator / batteries


Here's an example of how to:


Wiring a new charger From Maine Sail:

http://forums.sailboatowners.com/ind...5/#post-880275
and
https://marinehowto.com/installing-a...ttery-charger/

[john61ct]

But even primitive fixed-amps per output units, just stack / jumper them multiple or all onto your batts as you like.

But yes a well designed setup with just one higher-amp output is better, simpler.

Remember the charger must cover all loads first, only leftover current goes to the banks.

And they should get at least .2C current, over .3C for AGM.

[friz]

Originally Posted by ranger42c

Newer/better 3-bank chargers will put as much current on each "line" as each bank will accept -- within overall limits of the charger and the batteries. So no, it's not always necessarily a "10-amp-per-output" equation. No need to "combine 2 lines" to make that happen. IOW, the charger is indeed supposed to be "smart enough."

A 30A charger isn't necessarily optimum for a 400-Ah bank, and if you decide to add battery capacity later...

-Chris

Thanks, I was hoping for that answer about the charger being "smart". Boat is a trailerable 28' cabin cruiser. I have not done a power consumption spreadsheet as of yet. I think I'll start one today. Good point about expanding the house bank later.

[ranger58sb]

And John also made a good point about covering all in-service loads first, then charging comes afterwards.

-Chris