Info on "on-board" battery chargers

[GoneFission]

Mod Edit: 8 Dec. 2014, This was originally an eBay link for three bank chargers. The ensuing discussion has information value even though the link is long broken.

Can't beat this one  - $100 for a 40Amp, 3 bank charger?

[seabob4]

That is a good deal John, but IIRC, the ProTech series is NOT waterproof like the ProSports...

[GoneFission]

Bob - I may have missed one, but I don't know of anyone who makes a waterproof 40 amp marine charger.  I think the ProSports and most others stop around 20 amps, and the ProTournament models only go to 30 amps.  It's just hard to put that much heat/current in a sealed case without a fan, and open case, or really big heat sink fins sticking out...

[seabob4]

Yeah John, the ProTech models are more for cruiser type boats, that have more batts than our little dinky things and have the machinery space to keep them away from the elements and the occasional straight washdown from a hose!

[RickK]

Wonder if you need to plug it into a heavy current circuit - like 30Amp.  I realize if you step down the voltage you can step up the current but it didn't say whether it can be plugged into normal 15amp circuit.
I do need something like this for the 170.

[seabob4]

Rick, you'll be fine on a 15A.  Remember, the input side, 120VAC, is high voltage/low amperage, whereas the output side, 12VDC, is low voltage/high amperage.  If you would decide to mount it permanantly on the 170, keep it dry!!

[icemanbryan]

A duplex plug should be on a 20 amp breaker.

[seabob4]

Bryan, you mean a 2-prong with the unit double-insulated, so that you have N and hot being "plugged in"?  All the chargers I have dealt with (Guest, ProMariner, Charles, etc.) are standard 3-prong plugs.  Note on pg. 13 of the install manual...http://promariner.com/wp-content/upload ... Manual.pdf that 14A is the draw...so 15 will do the trick.  20 would go past my realm of comfort...

[icemanbryan]

Bryan, you mean a 2-prong with the unit double-insulated, so that you have N and hot being "plugged in"?  All the chargers I have dealt with (Guest, ProMariner, Charles, etc.) are standard 3-prong plugs.  Note on pg. 13 of the install manual...http://promariner.com/wp-content/upload ... Manual.pdf that 14A is the draw...so 15 will do the trick.  20 would go past my realm of comfort...

No, my bad.
I was thinking a house duplex plug

[RickK]

I'm going to have a 24V setup, so no common neg between two of the batteries.
I'm not sure that I can use this unless I have a switch that separates the 24V setup into two 12V systems for charging.  Am I wrong in my thinking here?  Unless the charger handles isolating the batteries and can treat them as 2-12V batteries instead of a 24V setup.

[gran398]

While we're on the subject...how is 36V normally wired?

[seabob4]

While we're on the subject...how is 36V normally wired?

Positive to negative between each of the 3 batts, Scotty, then the leads from the TM are...positive to the positive of the first batt, negative to the negative of the last batt...

[seabob4]

Rick, the Guest ChargePro series allows you to hook straight up to a 24V bank, but there is no mention in the Promariner manual about this ability.  If you're read the manual I linked to, it says that PM makes a 24V charger.  Based on that, I'd say, in a 24V configuration, you can't use that charger.  But...you could always install a simple disconnect in the jumper between hot and ground on the batts.  Just turn it to OFF when you want to charge, that will revert both batts back to single 12V units...

[GoneFission]

Rick - the 2 or 3 bank chargers can be used with a 24 volt hookup as long as you isolate your AC and DC grounds.  The charger sees 2 batteries with 12 volts between the leads for each battery, but does not see the connection since each battery is isolated inside the charger.  I've done this setup several times (got it on my CCP now) to run a 24V trolling motor.  I run 12 volts to accessories and engine off the main battery and have linked the main and the second (second is deep charge) together to run the trolling motor at 24 volts.

[RickK]

Rick - the 2 or 3 bank chargers can be used with a 24 volt hookup as long as you isolate your AC and DC grounds.  The charger sees 2 batteries with 12 volts between the leads for each battery, but does not see the connection since each battery is isolated inside the charger.  I've done this setup several times (got it on my CCP now) to run a 24V trolling motor.  I run 12 volts to accessories and engine off the main battery and have linked the main and the second (second is deep charge) together to run the trolling motor at 24 volts.

I don't have an AC system in the boat  

Merry Christmas  :santa:
So John, is this what you have, on the left - compared to what I will have on the right?

And you think the charger will see three isolated batteries?  The directions said to jumper all the batteries' negs together and bring one line back to the charger - that is the part that I'm leery of.