battery management switch

[tomschauer]

Something else to check. The screech m the battery charger. Without 120 volts, the battery charger should not do anything. Are you sure you don't have an inverter and are using the batteries for 120 volt loads? That could drain your batteries quite fast depending on what you are running.

[Viper]

Source of the post .....Without 120 volts, the battery charger should not do anything. Are you sure you don't have an inverter and are using the batteries for 120 volt loads? That could drain your batteries quite fast depending on what you are running...

+1
That's why I asked earlier if there was an inverter or some other device hooked up that triggers a low voltage alarm. I haven't come across any typical chargers that do that.

We also still don't know the battery specs which makes a huge difference. Are they 24, 27, 29, 31? What is the spec/capacity? If they are cheap 24s for example and the fridge is original, ya I can see a problem. Need some things confirmed/questions answered so opinions offered aren't based on assumptions.

[SkyeToo]

thanks again for the clarification. my fridge gasket is not great and it may very well be over-running. That I will fix first after launch.

happy 2019 and great boating season to all.

bruce

[SkyeToo]

tomschauer wrote
As others have tried to explain, you don't really have a house and start bank. The battery selector switch powers both house and start loads with whatever bank is selected. Soooo, when switch is at 1, all 12 volt loads are powered by whatever batteries are connected to that side, including the engines. Same with the other positions.

Well... there are 2 deep cycle batteries (brand new, marina installed and tested) and a brand new starter batter. So not sure what you mean that I don't have "a house and start bank". and yes, "1" should be engine start, "2" house only. What I have not clearly determined is which batteries are connected to which side of the switch. Reading the Perco switch manual, it seems evident that the engines should NOT start if the switch is in the "house" position (can be wired to either 1 or 2 obviously). Meaning, there should be no connection from that battery to starter motor in that case. "All" is, well.. all. no issue.

I am beginning to think that the fridge may be part of the problem cycling too often on DC.

What am I missing here?
Thanks
Bruce

[SkyeToo]

I will have to check/pursue all these excellent suggestions when the ICE is OUT! May, 2019. During the winter I live far away from Georgian Bay. No way to do anything except wait...

Thanks again.
Bruce

[bud37]

Bruce I dont think you are missing anything.......A friends boat he had for years, does all his own stuff....one day the port engine would not start....lots of batteries etc.....after about 2 hours of testing we found the guy that had installed the battery charger and bank of 6 volts had wired everything funky......I guess that is an example of you never know what someone has done before you, even if it has been years......see you in the spring, we will sort it then..........

[Cooler]

Take this with a grain of salt, cause I do not know electricity, except it is funky. If this helps, good. If it is too funky, disregard. Last spring I wanted to find out which battery was #1 and which was #2. I thought if I disconnected 1 battery from the system, I could turn my selector to 1 or 2, turn on a DC salon light, and that would tell me if I was actually disconnecting 1 or 2. Well, although one battery was disconnected at terminals, the light still turned on when selector was turned to either position. The guy that fixed it discovered the wires coming from the charger to the back of the selector switch were flipped. He said those flipped wires created a parallel wiring of the batteries, so the selector did not isolate the draw from batteries. Therefore any batteries connected would draw down to the demand for current from any DC component. He switched the wires to where they should have been and everything worked the way it should. Batt #1 did not allow light to turn on, when it was disconnected. I now know which is which, and can keep one battery fully charged for starting. Shows even the factory guys can mess up at construction.

[tomschauer]

[quote="

Well... there are 2 deep cycle batteries (brand new, marina installed and tested) and a brand new starter batter. So not sure what you mean that I don't have "a house and start bank". and yes, "1" should be engine start, "2" house only. What I have not clearly determined is which batteries are connected to which side of the switch. Reading the Perco switch manual, it seems evident that the engines should NOT start if the switch is in the "house" position (can be wired to either 1 or 2 obviously). Meaning, there should be no connection from that battery to starter motor in that case. "All" is, well.. all. no issue.

I am beginning to think that the fridge may be part of the problem cycling too often on DC.

What am I missing here?
Thanks
Bruce[/quote]

When you have a single battery switch, that switch controls all DC loads, both engine starting and house loads. So, if you have it in position 1 the batteries connected to the #1 line side of the switch power all of your DC loads, starting and house. If you have it in position 2, any batteries connected to the #2 line side of the switch controls all DC loads. With a single battery switch, your engines and house are not segregated on the load side. With what you have you would want to start on the #1 position and switch to #2 when not starting or running. To isolate the engines from the house you would need to change the load side wiring on the switch. This would leave you with no house power at all when switched to #1. To do it properly you would need to add second battery switch (preferred) or direct wire the starting battery to the engine starter leads. If you do this (direct wire), you don't have the ability to use the house batteries to start if needed or to have the alternators charge the house batteries if needed.

[Cooler]

Tom - good explanation. The confusion here is around the terminology. While SkyeToo is choosing his deep cycle batt's as his "house" batteries, and the "starting" as engine source batteries, that terminology is muddling the actual wiring arrangement to the single battery switch. I only know this because my last boat had "house" and 'start' wired separately. He should figure out which batteries are connected to which positions on the switch. If he has 1-2-all type switch, he could have a combination of deep & starting on each. If that's the case, and the starting batts are weak, they will drag down the deep cycles and reduce their longevity. If the switch is not wired correctly, like mine were (reference post 2 squares up) then the batteries on each position are not isolated. That is not the purpose of the switch. Hope this helps, but it does get confusing, at least to me. This is also part of the reason Carver puts all deep cycles in at the factory. That screech sound could be coming from a carbon monoxide unit. I had a low batt alarm built into one of those in my Cruisers.

SkyeToo - I doubt your switch or fridge is bad. Engine starters are connected so they will start with either position on switch accept for Off. You are on the right path, trying to determine which batteries are connected to which switch position. Hopefully you can see which battery terminals are ganged together, then put all deep cycles together on one position. Put starting batt on the other position. Try turning on a couple of lights in the salon, because they should turn on in one position or the other, and ALL, both not either position, if the wiring is correct. Here is that link you were requesting, but there is no wiring diagram. https://carveryachts.blob.core.windows. ... m-boat.pdf er

[Cooler]

SkyeToo - in that final sentence I meant to write ----Try turning on a couple of lights in the salon, because they should turn on in one position or the other, and ALL, BUT not either position, if the wiring is correct. (Spell check does us no favors) Bet you can't wait for winter to get over! Me Too! er