Battery puzzel

[JHarwood]

Hi;

I have a Hunter 340 with lots of Battery power. Meand'er has two pair of 6 volt cart batteries plus a 24 volt battery. I don't even know what the 24 volt is for or which of the 6 volt pairs are for start or house. The selector switch is only marked with 1 and two. I assume "1" is start but if I select "1" she has very little cranking power (has plenty on "2" or both). Running and charging on "1" makes no difference. The smart battery monitor ("Your-Meter" by Cruising Equipment Company) usually displays identical readings (volts, amps, amp hour draw and hours remaining), regardless of switch selection. I say usually because somehow I changed something an now it displays the 24 volt readings. I don't know how to change that back to monitor 12 volt.

How can the cranking be low on the "1" setting when it shows identical readings on "2" and "Both". I've had the boat for two years and it's always been this way. We have no marine services on our Island so I've procrastinated but needless to say it would be great to figure this all out.

Thanks. Jeremy

Any Thoughts or experience with this??

 

[Don S/V ILLusion]

Jeremy
First, I'd check to see where the cables run from both sets of batteries, particularly the 24v one since there isn't much a typical boat has which runs on 24v.
Next check where the cables run from your battery monitor and shunt which likely by-pass the switch if it is wired correctly.
Also check to see how the 6v batteries are inter-connected, i.e., whether they are in parallel or series, i.e., + to + or + to - and report back.
Without knowing your wiring schematic, it's impossible to tell what is going on.

 

[larryw]

I agree with Don; make up a schmematic as best you can, post it and you'll get more responses from the engineering types.

 

[Bill Roosa]

Ground circuits

If you rewire the grounds the system will operate fine but the shunt that measures currents will now be in another circuit so it will be measuring a different set of circuits.
I understand that you don't know electricity but we can't do much with out a diagram. Perhaps we could start with a good picture of your electrical panel front and back and your battery compartment(s)

 

[JHarwood]

Thanks;

I know this was not great information for you but you've allready got me thinking a little differently. The only extra info I have at the moment is the the 6 volts are in parallel to make two 12 volt banks.

Don; I saw the shunt in the manual and you said it would bypass the switch if wired properly. That could help with my understanding things. Can you explain how that's supposed to work? It sounds like I should be able to pretend the switch isn't there and it's selection is irrelevent. Is that accurate?

I'll have to get down to the boat to get some pictures. I don't know if I can get at the back of the battery monitor but I'll try.

Thank again.