Onboard Charging question

JDK426

Cadet
Joined
May 24, 2009
Messages
16
I hope this is in the right area,but im very new to boating and fishing but enjoying every minute of it. My question is to due with onboard charger for batteries. Ok i guess i get the idea of 1,2,3 bank chargers. assuming 1 battery is 1 bank. I only hope im correct on that term. Anyways the real question falls here. I have 2 12v batteries ran together for the 24v trolling motor. Then i have a seperate 12v battery for starting the motor and the bilge pump and running lights. Ok so my question falls here. If i am correct on the bank system im assuming. Would i need a 2 or 3 bank charger for onboard. The boat was already wired the way it is 2 12's running to 24v Trolling Motor and starter battery,running lights,bilge pump running on 1 12v battery. Please help me i am ready to buy a onboard charger . Just trying to figure if i need a 2 or 3 bank charger. And i guess i can ask more questions once i figure that problem out. Thanks a ton and this board has been my biggest help in boating problems. All of you guys are A+ in my book. Thanks, Jerry


Sorry about the mistake ive made. I didnt know there was an electric section on the forum i appologise for not paying attention. Ive created another post in that section so i will rule this one as dead
 

JDK426

Cadet
Joined
May 24, 2009
Messages
16
Onboard Charging question

Ok i posted in the wrong section a few minutes ago and i appologise. But my question. and ive read them all on here,but still not quite understanding as to they are a bit different from my question. I have 3 batteries on my boat. 2 12v's wired to 24v Trolling motor alone. Then my starting battery with bilge pump lights wired to it. I am going to purchase an onboard charger. But im not electronically inlcined whatsoever. So im assuming 1,2,3 bank is meaning a battery=bank. Correct me if im wrong, But if im wanting to charge the 2 12'vs for trolling motor would that be conscidered 1 or 2 banks assuming my theory is correct. Also if its 2 banks for 2 12vs that are connected. Im only assuming id need 3 banks to charge all 3 batteries. Any help or insight on this would be greatly appreciated. Im sure if anyone can shed some light on this i can buy one and go by the instructions on how to wire it. Im just illeterate to anything without instructions lol. Thanks a ton, Jerry
 

Splat

Lieutenant
Joined
Jul 20, 2008
Messages
1,366
Re: Onboard Charging question

Yes a 3 bank 1 bank=1 battery is what you'll prolly want. However this may depend on a few factors. I know its never easy.

In you current configuration, the lights and bildge are drawing off the starting battery. If your running lights and kill your starting battery do you have a recoil backup? Or are you stranded. You can wire everything else to one of the trolling batteries, this will give to the necessary 12volts, and leave only the engine start on the starting battery. If the starting battery is only used for engine starts, the onboard alternator(if equipped) should be able to replenish the battery just fine, thus only leaving the 2 trolling batteries to worry about, thus only needing a 2 bank charger.

See where I'm going with this?

Personally however, I would wire everything so only the engine start is on the engine battery maybe even the fish finder, everything else on the deep cycles, and install a 3 bank charger like the pro mariner. This charger will only use enough of the amp necessary to charge the starting battery, then devert those charging amps to the remaining banks to top them off quicker.

The possibilities are endless.

Hope that helps, if not keep asking away, you'll have to excuse me it late, I'm so tired I can't sleep, I have to be up in like 5 hours, and I've resorted to typing on my blackberry so I don't get out of bed. I'm not sure anything I've typed tonight made sense.
Bill
 

brown_one

Petty Officer 3rd Class
Joined
Jul 24, 2008
Messages
75
Re: Onboard Charging question

3 banks. 1 for each battery. look under the electrical/electronics forum. lots of info there.
 

wingless

Petty Officer 2nd Class
Joined
Jul 7, 2009
Messages
195
Re: Onboard Charging question

The 50A three-bank Charles charger I installed on my boat share a common ground, making it unsuitable for the 24V battery configuration.

The charger needs fully floating outputs to permit connection in series. Or, a totally separate charger is required for the series battery non connected to ground.
 

Splat

Lieutenant
Joined
Jul 20, 2008
Messages
1,366
Re: Onboard Charging question

The 50A three-bank Charles charger I installed on my boat share a common ground, making it unsuitable for the 24V battery configuration.

The charger needs fully floating outputs to permit connection in series. Or, a totally separate charger is required for the series battery non connected to ground.

Huh?

What is a fully floating output? That's a new one to me.

Not saying your wrong but could you clarify that one

Bill
 

wingless

Petty Officer 2nd Class
Joined
Jul 7, 2009
Messages
195
Re: Onboard Charging question

A AC/DC charger or power supply will have one or more outputs.

Those outputs are usually floating, meaning that the outputs are not clamped to a reference voltage, like ground.

It is typical to use an internal high-resistance connection to ground, so that the output doesn't drift up to some dangerous voltage, with respect to ground, but it still permits either output to be connected to any desired potential, within the specified range for the device. That is connecting battery negative to ground, or to any voltage within ?300VDC of ground is typical or okay for the charger or power supply.

The issue for charging two 12V batteries in series is that the 2nd battery, connected between +12V and +24V, needs to have a charger that tolerates charging a battery that isn't connected to ground.

Bad things will happen really fast if the 12V connection is grounded by the charger.

So, a multiple output charger could be used, if each of the outputs is fully independent and may be floated to a different reference potential, with some connected to ground and one connected to 12V.

There are probably some out there. Mine isn't one of them.

Another option is to use an additional charger, just for the 2nd battery on the 24VDC. That one output would be referenced to 12V.
 

JDK426

Cadet
Joined
May 24, 2009
Messages
16
Re: Onboard Charging question

Ok splat its making more sense,but as far as recoil backup i have no clue about that one or even how to check. Im a new boat owner and not very fond of anything to do with electricity lol. But im getting the general idea here. Im just curious how hard it would be to change the wires to one of the 12v that are pushing the trolling motor. I think engine start is far more superior than trolling longevity lol. I will try to ask my buddy thats a bit more sophisticated with electricity to ask him how everything is ran exactly. I am pretty sure its as i stated. So a 3 bank wouldnt hurt but a 2 bank would be more neccesary if i connected the onboard charger to the 2 12v's pushing trolling motor (and soon to be bilge pump lights etc). I am gaining alot of knowledge from what you are saying,but im just stumped on this recoil backup situation. I am going to try to find out more specs about it. Or if you know a simple way to tell please do tell me im all ears. I thank you guys for your answers this forum is probally the biggest help ive got. Thanks once again, Jerry
 

Fl_Richard

Lieutenant
Joined
Jan 21, 2005
Messages
1,428
Re: Onboard Charging question

A recoil starter is a rope start. If you've got a big engine forget about it. If its a little guy than it can probably be rope started.


If it's a big un' - Just take a pair of jumper cables with you. If your stating battery dies jump start the motor off one of the trollers.
 
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