Gulfstar battery charger

Hi, I have a Gulfstar44 and I’m in the process of updating my charger. I’m not sure what my old charger and the two alternators were feeding into as shown in the photo. The original charger and the two alternators feed into the bottom. There are three feeds out the top that go to circuit breakers and then to the engine bank, genset battery, and house bank.

It seems as if it takes all power sources and splits them up among the three battery banks but I’m not sure.

I’m putting in a Sterling smart charger that monitors the banks and sends each bank what it needs so I don’t think I want to run the charger thru this 1985 splitter?

If I hook my charger up to the batteries directly as shown in the instructions should I leave the alternators hooked up to this old splitter or is there a better way?

Boy that's an interesting setup. I'll be interested in the answers you get. Huh. I'm upgrading my charger too, from a 1995 Dytek 50 amp original to the boat, to a 2011 Charles 60 amp charger, mostly just because I got a good deal on it so what the heck, let's jump ahead 16 years. I haven't opened the Dytek cabinet yet -- I'm not sure what I'd do if I found something like that. Yikes.

Yes, It was definitely a surprise! The bottom left terminal that’s empty is where the pos lead from the battery charger went. The one in the middle and on the right side are the two alternators. The negatives all go to a shunt. There’s three lines on the side, one going to each battery bank. I’m tempted to run everything thru fused lines directly to the batteries and eliminate the splitter thing but would like to know what it is and does exactly before doing anything.

Good luck with your project, hope there’s no surprises!

Grey, I have a 49' and I can commiserate, but cannot answer, to your 1980ish wiring, specific questioning. I do believe my two battery chargers replaced that neat, albeit dated, wiring set-up.

Please keep us (me) informed as to progress.

We should stay in touch.

That contraption reminds me of the now outdated concept of a battery isolator with the voltage-sapping diodes that used to come with them. Maybe this thing was somebody's idea of a power post. It looks like the single leads from the alternators and charger all feed all three banks with zero isolation meaning one dead bank drags them all down, but without my VOM on it, I cannot be sure about continuity between them all.

Running the three leads of your newer charger directly to the banks through whatever fusing (if the individual legs are not fused at the charger) is where I would start. One my twin I had a separate, small charger for the generator battery. That's four banks, if you are counting, two mains starter, banks, one gen, and one house.

The alternators are a bit trickier. What I did on my twin was to run each alternator directly to a bank, port to the #1 starter with a combiner linking #1 to # 2 starter battery bank, and stbd directly to the house bank. There was the ability to switch in the generator to either alternator underway, but I many years steaming, I never had to alter the positions on the two multi-position battery switches and the single on/off one for the switching in of the generator. I have a drawing, and I remember the whole switchover to this system costing about 1500 bucks, lots of it cabling.

For fusing the battery charging leads to the batteries Blue Seas makes an MRBF 3 fuse holder that works exceptionally well for battery charger fusing.

Osprey, your right about it being 1980ish. I guess I should have mentioned that it’s a 1985 model, and I would bet it’s original. I’m still wondering what it is exactly and what it’s intended purpose was if anyone knows? The original charger was a charger/converter as opposed to the modern charger/inverters that we use today if that makes a difference.

I have a Magnasine inverter/charger currently connected to the house bank. The leads to the house bank coming from the mystery contraption were disconnected when I purchased the boat.

I would like to install my new Sterling charger in a similar fashion to the starter batteries. One lead from the charger and one lead from an alternator to each starter bank. This would keep my starter batteries charged while underway. I run my genset for a couple of hours every day while underway to charge the house bank and provide power for bigger draws such as the water heater, stove, ac., etc..

Rgano, Are there any advantages to leaving the two engine start batteries as separate banks and using a combiner to connect the alternator over configuring the batteries in a bank and wiring the alternator directly using a fuse block connected to the bank?

Comodave, thanks for the heads up on the fuses. What do you think of the Blue seas mrbf2 terminal stud fuse blocks? One on each starter bank with one lead to the charger and the other to an alternator for each bank?

Thanks for all of your replies

I use them for a lot of places. You want to put them at the source of power to protect the wiring.

Quote:
Rgano, Are there any advantages to leaving the two engine start batteries as separate banks and using a combiner to connect the alternator over configuring the batteries in a bank and wiring the alternator directly using a fuse block connected to the bank?
Unquote.

Well, I am of the opinion that if you are going to fully take advantage of the redundancy of twins that they should be in every way separately supported. I NEVER cross-connected fuel their fuel supply and I never depended upon one battery bank to start them.

Thanks, I have crossover switch’s so I can start the engines with either the generator battery or the house bank if needed

Greyhawk said:

Thanks, I have crossover switch’s so I can start the engines with either the generator battery or the house bank if needed

Click to expand...

I had gen-to-main capability as well as House-to-main start capability. Was I paranoid?

Rgano, I don’t think you’re paranoid. There’s no such thing as being too careful right ?

You have got me thinking though. I think I might connect one alternator to a fuse block on the house bank and one alternator to an acr or combiner and then to fuse blocks on both the engine and genset starter batteries.

What are you using as a combiner on your set up?

Does the combiner go between the alternator and the two banks, ie: one wire in from alternator two wires out to the banks? Or does it go in between the two banks?

Yes that looks like a diode based battery isolator, with multiple diodes in parallel to increase the current carrying ability of the device. Although I don't recommend them and would not have one, you can still get new ones and they are better than they used to be.

https://www.littelfuse.com/products/battery-management/battery-isolators/diode-battery-isolators.aspx

The mrbf2 terminal stud fuse blocks are great, as long as they can handle the current that is required, they are limited to 300A which could be a bit low for engine starter motors.

As for combiners, it sounds like you have twin engines?

Combiners are a terrible way to charge batteries, when you join two banks they are inevitably at different levels of charge, and are also usually different capacities,. level of heath, etc... If it was my system, I'd wire up each alternator to it's own start battery, eliminate all the combiners (except those used to parallel for emergency start usage only) and then put a DC-DC charger on each start battery to charge the house bank.

Sterling makes some excellent DC-DC chargers made specifically for the purpose of charging a house bank from an alternator charged start battery.

Yup... diode isolators IMO
Here is a link outlining what I replaced mine with and why. See Charging system mods.
https://dkloeber.wixsite.com/bacchus/project-pg-4
There are lots of better options available today than those diodes.

Options, options, options!

Well this just got a little more confusing.

Sbman, thanks for the info on the dc-dc chargers.

Bacuhus, thanks for the links to your project pages and the info on the cvsr’s.

I never heard of either of those products before. I’m going to have to do my homework and figure out what’s going to work best for my system.

Have a 1980 Gulfstar Sailmaster. On my boat, the original configuration had the same arrangement consisting of diodes on a heat shield that served as a battery isolator. In my case, I replaced the alternator and battery charger to house bank and added Balmar Duo Charge unit to starting and windlass batteries. Left the original wiring including the diodes in place because also had battery paralleling contactors with switch at helm. PM me if want more detail.