Help Please New Onboard Charger

[bassinbeno]

Just bought a new 3 bank ProMariner Promite 553 onboard charger. I have a 12V motor guide foot control trolling motor I inspected it and see no switches anywhere to convert to 24V but would like to add a 2nd battery for the trolling motor since my onboard charger will charge 2 trolling batteries and the cranking battery. Can anyone give me a simple way to wire this so that when one battery is dead I can switch it over to the other. Also the instructions that came with the onboard charger said dont mix batteries such as gell cell and lead acid batteries however my 2 trolling motor batteries are gell cells and my cranking battery is a lead acid core do you think this will matter since the the feed from the onboard charger will be seperate from the gell cells. Thanks in advance any help will be appreciated.

 

[Silvertip]

Re: Help Please New Onboard Charger

Adding a second trolling motor battery takes on two forms. You mentioned 24 volts. Two 12 volt batteries in series provide 24 volts. Two 12 volt batteries in parallel still provide 12 volts but doubles the run time since you now have two buckets of electricity instead of one. So lets stick with 12 volts since you have a 12 volt motor which is not designed to run on 24 volts anyway.

You really don't need to connect the troller batteries to the engine since your engine doesn't have enough alternator capacity to bring them up to full charge in a short run back to the dock. You therefore can simply parallel the two batteries, connect them to your on board charger and be done with it. No switch is necessary.

Here are typical 12 volt parallel and 24 volt series connection schemes.

 

[bassinbeno]

Re: Help Please New Onboard Charger

You could'nt of made it any clearer. I wasn't sure on the parrelel connection. Thank you very much. What about the gell cells mixed with the lead cell think it will matter ?

 

[Silvertip]

Re: Help Please New Onboard Charger

Mixing battery types is not a good idea and they may even have different charge profiles. Batteries in parallel should be of the same type, prefereably the same manufacturer and of the same capacity (reserve capacity or AH rating). Your charger may have selectable profiles but it may be selectable for ALL batteries (not individually selectable for each battery).

 

[tomynoks]

Re: Help Please New Onboard Charger

Silvertip,
He said, "my 2 trolling motor batteries are gell cells and my cranking battery is a lead acid" so, that should be ok, right, since the 2 gel cells are for the TM and the acid is for cranking they'll use different banks for charging?

My configuration will have two in parallel for my 24v TM and one 12v for cranking. My question is this, can a 3 bank charger charge both the two TM batteries in parallel (24v) and the cranking battery (12v) at the same time or will I have to charge the TM batteries separately?

Thanks,

Tom Smith

 

[Silvertip]

Re: Help Please New Onboard Charger

First, you don't have 24 volts if your troller batteries are in "parallel". You still get 12 volts from that configuration. "Series wiring provides 24 volts. Look at the previous diagram for the comparison. Second, you missed my point about charge profiles. The charger may have a charge profile selector switch but it may not allow adjusting profile for three separate batteries. If it does, that's fine. Set one output for lead acid, and the other two for gel, AGM or whatever profiles it accomodates. If there is only one profile adjustment, whatever that adjustment is set to is the profile that will be used for all three batteries. Yes, a three bank charger can charge all three batteries of different types IF that charger has a charge profile selector for each bank. if all three batteries are the same there is not an issue. But if they are different, then each output would need a separate charge profile selector.

 

[bassinbeno]

Re: Help Please New Onboard Charger

Thanks for the help. I decided to go with only one trolling battery since it was more than enough for a entire day of fishing. (why add extra weight) I moved it from the rear of the boat to the storage compartment in the front of the boat (gell cell) and mounted my onboard charger in the rear. The lead acid cranking battery is still in the rear my promarine 5/5/3 charger seems to work correct with both 5 amp leads hooked to the trolling motor battery and the 3 amp lead hooked to the cranking battery. This was a project running the wires but I think it sure will help with spreading out the weight of the batteries as to getting the boat to plain faster and running more level since it is a side consule. Thanks, Bassinbeno

 

[tomynoks]

Re: Help Please New Onboard Charger

OOps..... I meant "in series" for 24v