Little black box - what is it?!

[fastback]

I am trying to sort out my electrics on my '99 Hunter 340. The previous owner has done some questionable wiring changes with the switch alt etc.:cussing: Such as everything is on #1 on the battery switch. One Balmar alt repair, thank you very much.

My question is what is this box? There is no identification on the box. Filter? Combiner? Both bottom wires go to the switch - common and 1, and the small wire on top goes to negative bus.

Anyone recognize this or educated guesses?
Thanks!

PS - I posted this in the Hunter Big boats but as it isn't an OEM part I thought the chances of someone recognizing it might be greater here!

 

[Delezynski]

Look like a battery combiner. It connects both batteries/banks when charging, but isolates them when and discharge starts. It might have a small LED on to to indicate combined state.

Greg

 

[fred1diver]

to me it looks like a heavy duty relay

 

[fastback]

Thanks guys, I thought it might be a combiner but the PO had all three batt in parallel on switch #1, nothing on #2?! The red and black go to the common and #1... so a combiner would be nice, but in this set up there was nothing to combine.
Other suggestions were a noise filter.
I'm hoping someone can definitively ID this, or perhaps suggest some tests to determine what it is.
Thanks!

 

[Delezynski]

Do you have a picture of the top of it? Where the small black wire comes off.

Greg

 

[fastback]

Greg, no photo of top. I'll swing by the boat tomorrow and pull it off to see if there are any markings on the back side. The way its mounted I can't see the top...

 

[Delezynski]

Sure looks like the same battery combiner I have (now replacing it). I got it from West back in 01 or so. The top of mine looks sort of like the photo...

But mine only has one LED on the top.

Greg

 

[capta]

If it's a battery combiner, it is not functioning; it needs another red wire on the bottom for the second battery, I would think.
Be very careful. If it is a relay, as wired it could short the red to black wire, for what reason I couldn't guess. Follow the wires and decide if it's functional; if not remove it.

 

[RichH]

Yup, its a battery combiner.
Probably, either its made for WM by Yandina (Yandina.com) or is a direct purchase from Yandina. Their website has all the proper 'hook up' diagrams, including the usually needed large AWG 'sensor wire' that runs between two batteries.

 

[fastback]

Thanks guys, had a chance to go down and un-mount it. Yes its a West Marine combiner. I installed the rebuilt alt and dragged the dead batteries home for a proper charge.

 

[Stu Jackson]

Keep the combiner, it's a great unit, guaranteed for LIFE by Yandina, even if made or sold by WM. Good unit for charging your reserve bank. I've had one since 1999 or so.

 

[fastback]

Good feedback.
Here's my second question. There is a direct set of cables from the Alt to a start battery, the combiner is going from feed to #1 on the switch, nothing on #2. Does this make sense? Can any one explain the logic?

 

[Maine Sail]

Good feedback.
Here's my second question. There is a direct set of cables from the Alt to a start battery, the combiner is going from feed to #1 on the switch, nothing on #2. Does this make sense? Can any one explain the logic?

The combiner should have two 6GA red wires, one going to each + battery post for each battery "bank". Alternatively the red 6GA wires can be routed to post #1 & post #2 on the back of the battery switch.

If your house bank is physically larger than the start battery then it would be wise to run the alt there first. This means the combiner has to pass less current through it each time it parallels the banks.

Get rid of there large black wire (next to the red one) as it will only invite a future dead short when someone thinks it is a negative/grounded conductor.

 

[Delezynski]

Fastback,

Sorry to give ya bad news, but it sure seems like the time to do a re-wire!

Do as RichH said above and download the data. Take a look on the web for the wiring plan that fits your boat and you like, and jump in. There are a LOT of options out there. Just take it one step at a time and it's NOT all that hard to do.

Google up, or search Amazon for books on marine electrical systems.

It will be more time/work now that will pay off BIG TIME later on with knowledge of YOUR boat and trouble free cruising!

Greg

 

[fastback]

Thanks guys,
Planning on sorting it and rewiring, just trying to understand what "logic" might have been in play. I am leaning toward theDuo charge so I can run a house bank and an automotive start, but need to address the different charging requirements. And yes, I just had my alt rebuilt after switching to #2. My fault for not checking the wiring... Fool me once.

 

[H45DS]

Thanks guys,
Planning on sorting it and rewiring, just trying to understand what "logic" might have been in play. I am leaning toward theDuo charge so I can run a house bank and an automotive start, but need to address the different charging requirements. And yes, I just had my alt rebuilt after switching to #2. My fault for not checking the wiring... Fool me once.

If you are referring to the Balmar Digital Duo Charge, it will accommodate a different starter battery type than the house bank. See http://www.balmar.net/duo-charge.html for more info.

 

[fastback]

Yes, the Balmar DuoCharge, I've got the Balmar external reg (612) so I could set the program for deep cycle, and the duo charge for an automotive bat.
Our club is a mooring field so I'm looking to add solar too, plugging in is a luxury, not a way of life!

 

[Maine Sail]

Thanks guys,
Planning on sorting it and rewiring, just trying to understand what "logic" might have been in play. I am leaning toward theDuo charge so I can run a house bank and an automotive start, but need to address the different charging requirements. And yes, I just had my alt rebuilt after switching to #2. My fault for not checking the wiring... Fool me once.

Keep the Yandina it will charge a starting battery and house bank just fine unless your start battery or house battery is GEL and the other AGM or flooded.

The ONLY time a Duo is really necessary is when the AUX battery must have a lower charging voltage than the house bank. This is pretty rare. AGM and Flooded batteries charge at very close voltages. Charging is about voltages not starting or deep cycle etc. etc..

 

[Stu Jackson]

Maine Sail's right. You should also check the SIZE of your combiner, since they made a 70A model and a 130A model. I bought the 130A model back in 1998 when I only had a 55A alternator, knowing I was going to upgrade and enlarge the alternator sometime in the future. I finally installed a 100A alternator and my combiner was just fine for it.

One of the things that is "indirectly" covered in the Yandina manual (http://www.yandina.com/acrobats/C70Manual.pdf) is that it is preferable to MOVE your alternator output from the C post of the 1-2-B switch to the house bank.

Like this:

Basic Battery Wiring Diagrams This is a very good basic primer for boat system wiring: http://c34.org/bbs/index.php/topic,6604.0.html

This is another very good basic primer for boat system wiring: The 1-2-B Switch by Maine Sail (brings together a lot of what this subject is all about)
http://forums.catalina.sailboatowners.com/showthread.php?t=137615

You simply do not need the duocharge.

 

[fastback]

Thanks, I did some reading (a great thread in here somewhere...) and you are right! I'm planning on going flooded all round so the combiner (I have) will do the trick! It's a Yandina 150 model (150 amps, apt is a Balmar 80amp) that has a voltage limit option (high voltage terminal) to keep the shared output to 14.2v so you don't cook a gel cell. This is great news as I can reuse the wiring and electronics.
I assume the alternator output and regulator sensor go to the house as the house bank will require the longest charge compared to the starter. I'll go with a three switch + combiner set up a la Don Casey and Yandina. Gives complete isolation, automatic charging.

Any guesses as to why the previous owner would have the combiner across the common and #1 on the switch? Nothing on #2. With a set of cables going straight to the alt from the start batt, the start ends up connected to the common anyway by virtue of being on the same terminal on the alt- so there isn't anything to combine that isn't already combined! (explains my draining start battery).

Am I missing something or was this just a misguided DIY?