MPPT to Battery Connection

[SteveInMD]

I have two MPPT controllers. I want both to charge the house bank (four batteries in series). Do I connect the negatives from the controllers to the negative bus bar, and the positives directly to the battery bank? If so I assume I should go to the positive at the opposite end of the bank from the negative going to the negative bus, correct? I also have a shore charger and an isolator isolating the house, engine start, and bow thruster batteries, but I believe I should skip all that, right?

[DeepFrz]

Steve, check out this thread and I think its post 42.

Electric Circuit Diagram Software ? - Page 4 - Cruisers & Sailing Forums

[SteveInMD]

Originally Posted by DeepFrz

Steve, check out this thread and I think its post 42.

Electric Circuit Diagram Software ? - Page 4 - Cruisers & Sailing Forums

Thanks. So, yes, the MPPT neg. goes to the neg bus. I don't think I have a pos. unfused charge bus, but I will look. I'm thinking the switched side of the house on/off switch might be a good option.

[smac999]

Originally Posted by SteveInMD

Thanks. So, yes, the MPPT neg. goes to the neg bus. I don't think I have a pos. unfused charge bus, but I will look. I'm thinking the switched side of the house on/off switch might be a good option.

no it would have to go on the battery side of the swith.

also you need to fuse the controllers at the you point you connect them to the battery / bus / where ever.

the pos post works but somethings can get messy. and you're only allowed 4 wires. and you likly have atleast 2 already. (jumper and switch feed)

[SteveInMD]

Originally Posted by smac999

no it would have to go on the battery side of the swith.

also you need to fuse the controllers at the you point you connect them to the battery / bus / where ever.

the pos post works but somethings can get messy. and you're only allowed 4 wires. and you likly have atleast 2 already. (jumper and switch feed)

O - good point. If it were on the switched side I would never be able to shut the house power off to the boat. Except for at night!

[moseriw]

[pcmm]

The neg should go to your neg bus bar or post. The positive side should go to the switched side of the house battery switch, otherwise you can never disconnect the battery for servicing without having a spark when you reconnect. That is unless you "fuse' the positive circuit to the battery with a circuit breaker.

the whole point of the battery switch is to be able to disconnect the battery from all sources. The only exceptions to this are the bilge pumps and the VHF radio

[smac999]

Originally Posted by pcmm

the whole point of the battery switch is to be able to disconnect the battery from all sources. The only exceptions to this are the bilge pumps and the VHF radio

to disconnect all loads. sources like solar, battery chargers, alternators etc are not swtiched.

[David B]

Originally Posted by smac999

to disconnect all loads. sources like solar, battery chargers, alternators etc are not swtiched.

Yes, the normal main isolators have shore-charging on the battery side, so that when you leave the boat, you flick all isolators off, and all loads are off.
Exceptions can be bilge-pumps (you will need to check how yours is wired).

For solar, it should also be on the battery side of the main isolators for the same reason, but you should always have fusing between the battery and the solar controller. Apart from safety, that is a crude way of isolating from your battery when you are working on your solar system.

[SteveInMD]

Since I have a Beneteau I also have a DC ground disconnect switch. I never really understood why one would install such I thing, but I suppose it would shut down power going into the batteries from all charging sources.

[mitiempo]

Originally Posted by SteveInMD

Since I have a Beneteau I also have a DC ground disconnect switch. I never really understood why one would install such I thing, but I suppose it would shut down power going into the batteries from all charging sources.

I've never understood Beneteau's DC negative switch either.

All charge sources should go to unswitched buses - both negative and positive. The main battery switches should have nothing to do with charging.

[David B]

Originally Posted by mitiempo

I've never understood Beneteau's DC negative switch either.

All charge sources should go to unswitched buses - both negative and positive. The main battery switches should have nothing to do with charging.

Now you have me thinking - a. does our -ve isolator isolate the entire circuit (and therefore the chargers), and if so, b. did I flick it off before leaving our boat for 10 months or not?
a. would be a good idea
b. I hope not !!!!!