Battery switch question,need help.

[larlarsa]

My friend want to add a Perko battery switch to his boat,the reason is the boat have little leak,he docking the boat at the marine,usually he go up there once a week,for last year,he use the start battery to hookup the auto bilge,connect a two bank charger to the one of the trolling battery and the 2nd bank for the start battery to keep top the power,but in sometime of summer,when storm cross the dock,the shoe power will blown,sometime the owner didn't realize that, he forgot to reset the fuse.for safe reason,he want to connect two battery to extend the power for the auto bilge,he also want to add one more battery to extend the trolling motor run time too.

here i have a pic for the new setup,my question is :

1. can one of the charger bank charge two battery?

2.in this setup,when the switch on " both ",is the bilge run on all three battery in parallel.

3.any problem on this setup for the onboard charging.

4.what Ga of wire for those wiring?

i know when start on boating i need to switch back to number 2 only.

 

[glenn property of pam]

Re: Battery switch question,need help.

yes yes yes thick

1/ the charger can charge both at the same time but the batterys need to be matched on size pref 2 brand new batterys of the same brand because if one is week then it drags the second down.
2/yes when set on both then all 3 batterys are joined (but then number 1 becomes a problem)
3/yep you wouldnt charge one battery with 2 chargers and thats what you would be doing there is work arounds but i think its not a good idea due to the problems with size diffrence to start with
4/as the batterys could all be linked to start the motor even if that was not the intention then all wiring should be as large as your starting cables.

if 2 deep cells can not keep the biege pump running for a week then i would consider a shore powered device that runs a seperate pump set just slightly lower that the original so while on shore power neither battery is being used then if shore power fails and the level rises the battery one will pick up and take over

 

[larlarsa]

Re: Battery switch question,need help.

Thanks for the reply,

but i don't understand your meaning on #3

lets assume i have two same size and year of the battery for the trolling motor hooked up for bank#1 on charger,
an older one starter battery hooked on bank #2,is it a problem?

Thanks.

 

[glenn property of pam]

Re: Battery switch question,need help.

you have a dual battery charger when you change the switch on the perko to dual then not only did the batterys get connected but the two chargers also got connected so one charger will fight the other. also the two deep cycles will now try to equalize with the starting battery and if its week and not holding the same charge they will start transfering power across the switch to the starting battery at what ever max amps they can which is not good.

 

[glenn property of pam]

Re: Battery switch question,need help.

oh i forgot on your print both banks of batterys have to have a common ground or when you switch to the deep cells nothing will work except the trolling motor.

 

[larlarsa]

Re: Battery switch question,need help.

ok,i understand what you mean now,
but one of my friend have a three bank charger that use each bank for each battery,he have a 24 v trolling motor that's mean two battery in series,is he doing right?

 

[larlarsa]

Re: Battery switch question,need help.

i found a pic

 

[glenn property of pam]

Re: Battery switch question,need help.

yes for 24v you can charge as a 24volt system or 2 x 12v systems the better is the 2 x 12v way as each battery gets treated as a single unit. the chargers on that kind of set up have no commons between them so they wont play with each other they only sense the 12v across the battery (thats what the warning is about isolated outputs)

 

[larlarsa]

Re: Battery switch question,need help.

any way i can do the same i need?

or i switch to#1 insert of both,only run two battery in parallel.

 

[glenn property of pam]

Re: Battery switch question,need help.

a battery in parallel is part of a group thus it can not be treated seperate. you just need one charger for on bank of batterys in parallel. so you can have 2 in parallel on say A side of perko and one on the B side and as long and you never set to dual while you are charging thats not a problem.

 

[larlarsa]

Re: Battery switch question,need help.

ok,Thanks.

i just keep in mind to set it at #1 only when dock the boat with shoe power,switch to #2 when start the motor off the dock.