Multiple Charging Sources

[kaakre]

Some architecture questions for a refit--

I will have three banks of two batteries each. Two banks are house and one is starting/windlass. The starting bank is charged at 12V but is isolated by switching and put in series to get 24V for the starter and windlass.

All three banks are charged by the following: (2) 100 amp main engine alternators, 250 amps out of a generator, a shore power charger, wind generator and solar panels.

Question is-- can any combination of these charging sources charge directly into each if the batteries (through a common charging bus bar) without separation or will one interfere with another and I need some form of charging controller?

Keith

[sailingdog]

UMM.. One quick question... why two house banks. You'll generally be better off with one large house bank, rather than two smaller house banks.

Also, why do you have a mixed voltage system? It would be far simpler to have an all 12V system.

You should probably have a charge controller of some sort. Most wind generators will require one specifically designed for wind generators that can provide braking current to the wind generator when the generator starts to go too fast. Most solar panels will generally require one to be working at their highest efficiency... usually a MPPT-type charge controller will give you the best results there.

As for the two alternators and the generator, they should probably be going through a charge controller of some sort, to prevent them from overcharging and killing the batteries.

One thing that you don't mention is the size of the various banks, and what type of batteries you're using for them.

You really haven't given enough information to get a really useful response.

[kaakre]

Am considering two banks for the house-- will be combined for normal use but am considering being able to isolate two for use as a backup 24v starting source.

Mixed voltage is due to legacy items. Was originally a 220/24V Euro boat. Starters for engine and generator as well as windlass are 24V. Lower amperage is a benefit.

The charge controller issue is the question. Is there a company that sells such a product?

[Goodnewsboy]

It used to be that you used a battery isolator to prevent reverse current flow from a plurality of batteries connected to a common charging source.

A brief search yielded these little nuggets:
http://www.hellroaring.com/rv.htm
http://www.geocities.com/harald_nancy/isolator.htm
http://www.off-road.com/chevy/reviews/hellroaring/
http://www.cmsquick.com/tech_03_isolsys.html

I have no interest in any of them and there are no warranties express or implied!

[sailingdog]

Yes, someone probably makes a dual-voltage charge controller. Whether it'll do for what you need is a different question. I would personally recommend getting separate charge controllers for the 24v and the 12v sides of the system.

[kaakre]

Thanks Goodnewsboy and Sailingdog.

I will look into the isolator issue. Thanks for the links.

This is where I am going now.

Without a system level controller for the six charging sources (alternator 1, alternator 2, generator, shore power, solar, wind) I assume that I can only use one charging source at a time. Otherwise, I assume that the alternators will shut down the smart controllers or vice versa.

Main Engine Alternators

The alternators on the main engine are the single wire universal type with built in regulators. To avoid the lazy alternator problem from two regulators charging a common battery set I am considering having one charge the house and the other charge the start batteries.

Generator

I found a 5000 watt 220 to 110 coverter with some level of power conditioning. This could feed the 110 AC bus and a couple of smart chargers (one house/one start) that operate when the generator is used and the main engine is off.

Shore Power

Feeds AC bus and smart chargers when shore power is selected.

Solar/Wind

Probably product specific but these are common add-ons and the integration problems have probably been sorted out.

Keith