Two Alternators and One Battery Charger

[lamlie]

I'm planning to do wiring for a boat and i came out with few questions... I would be glad if anyone could help me with this.

My setup is that i have 6 sets of 2.2v gel type batteries connected in series with the total voltage of 13.2v, a generator supplying 240v to a battery charger, and 2 130amps alternator on the main engine. My plan is to run the generator when I need massive power and when the boat is not running, and switching to the main engine's alternator when the boat is running.

My question is..

1. Do I need any device to control the charge from the engine's alternator to prevent from overcharging.?
2. What device can i use to cut the power from the batteries once the power is 80% less?
3. will anything happen If i were to connect the alternators and the battery charger together, and what will happen if both runs on the same time.?
4. Since I have 2 alternators on the engine, can I use both in parallel which would supply 260A power to charge the batteries? Will there be any side effect to the batteries and/or alternators?

I think that's it for now, thanks in advance for your time.

[btrayfors]

Two questions:

1. What is the total AH capacity of your battery bank?

2. What kind of regulator(s) do you now have on the two alternators?

Bill

[lamlie]

q1. 6 x 700aH = 4200aH
q2. I dont have any.. do i need one.? Can you suggest me with any..

[sailfish2008]

no regulators , very interesting have you made a wiring diagram that you wish to use

[lamlie]

yes on paper.. not in the PC though.. i havnt figure how to do that yet.

Rough picture though,

2 Alternators on the main engine,
1 Damn big 25kv generator
6x 700aH batteries
80 amps Kema Battery charger/Inverter (2 in one)

1 8kv Air compressor for dive tanks
1 fridge (300 watts)
8 power sockets to charge laptops / cameras.

What i had in mind was to connect the two alternators together to the battery banks and also to the inverter/battery charger. and all of the AC load will be connected to the inverter except for the air compressor.

I was thinking on running the generator only when the air compressor is running and if the battery is dry while the main engine is not running.

advice.? thanks..

[btrayfors]

I think you have a total of 700AH @ 12V (6 x 700AH @ 2 volts = 700AH @ 12 volts).

If they really are gels instead of AGM's, you've gotta be careful to charge them properly. Gels can be ruined by overcharging or using too high a voltage.

This means you MUST have a regulator which can be set for the type of batteries you have.

I assume your alternators will take an external regulator, or can be converted to do so. If so, then you might use something like the new Balmar MC-612H regulator which can handle two alternators charging the same battery bank. And, it is fully programmable for the type of battery, various charging parameters, % of alternator output to be used, etc. It also accepts sensors for battery temperature and alternator temperature.

First thing is to verify that you really do have gels, not AGMs, since their charging regimes are very different.

Bill

[btrayfors]

Sorry...the new Balmar regulator which handles two alternators is the MC-614-H not 612.

Bill

[DeepFrz]

Unless you have 42 x 2 volt cells. In which case I think you had better rethink the size of your battery charger.

[james2001]

i got a zero drop battery isolator from a company in the north east early this spring. they're like automatic battery switches. They keep my banks seperated when they need to be automatically, and then allows the seperated banks to still get charged from my single imput. They had these zero drop battery isolators w/ 2, 3, 4 bank outputs, and i believe they had some for 2 altenator setups.

zero volt drop marine battery isolator

they had a few battery chargers that you could do 12v to 24v, or 24v battery bank to 12v bank charging too. They had chargers that worked not hooked into shore power some how, but i only bought the zero drop isolator. I've used it all this season and had good luck so far. will post if otherwise.

james