Parallel Battery switch????

[aquacraig@shaw.ca]

I seem to have something strange happening so need some advice. I normally run, and charge, with my battery switch on "parallel". This has always been fine and I seem to have lots of juice on both 32v banks. Recently, I had a cell go on one battery in the PITA stbd bank so I replaced the lot. After everything was back to normal and batteries fully charged, I monkeyed with the bow thruster and the darn thing turns faster on "stbd" or "port" than it does on "parallel"!
Does this make sense? I thought parallel would theoretically double my amps and give me more power and duration. I know I have 34v on full charge in both banks so why is the "parallel" worse?

Thanx

Craig

 

[Canuck Dennis]

I have similar issues with my Stb'd engine, it is counter rotation and draws 850 amps on start, paralleing makes no difference to tun speed, re wound that one to 24 V , helps a bit.

Not sure, but I don't think major loads are run through the batt switches, my parallel sw for mains is independant of the others in the elect panel.
Although my 32 v windlass can be paralleled through the batt switches.
May depend on how was wired originally.

Good luck..(great summer that was)

 

[aquacraig@shaw.ca]

Dennis, I don't have 1/2/both switches but the solenoid actuator toggle switch on the helms. The solenoid is working (at least I can hear it clicking) but I seem to have more amps from port or stbd than from parallel. I don't know enough about what the solenoid is actually doing to understand the reason for this. The same thing occurs with the windlass as with the bow thruster.(please....no shots about the wimp with a thruster!)

Craiig

 

[REBrueckner]

Aquacraig: your posts say two slightly different things..one mentions a parallel switch the other mentions a solenoid....in any case, its impossible for two banks to EACH give more power individually than a combination of them both. You are correct that paralleling your two banks should double your available power. Your new stb bank might do better alone only if the old bank is in weak shape...

Maybe somebody who is smarter than me will have a suggestion..otherwise testing actual current draw in different configurations will be required if you are concerned.

All the parallel function does (switch or solenoid is the same) is connect your two positive battery bank terminals together...think of it as a red jumper cable like you might use to jump start a car (the negative battery terminals on a boat are always connected, permanently.) When you parallel your banks for main engine start, does that slow each engine rotation??

With a manual parallel switch, it's about impossible for what you describe to happen. With a solenoid it's remotely possible if the solenoid itself is drawing a lot of power when activated, such as in a near short, its getting ready to fail, but that's VERY VERY unlikely.

What capacity are your battery banks and how much current does the bow thruster draw? Is this a new situation since you replaced the stbd batts?? When you test the thruster on port and stab, are your turning in the same direction?? I ask because it might be possible for the thruster to do bit differently between port and stbd thrust??

 

[sgharford]

I use my parallel solenoid when I start my stb engine. The house bank is hooked up to stb battery bank, if I don't parallel port bank in my Garmin chart plotter turns off from voltage drop. Based on this, I would also concur that twice the batteries, twice the juice.

 

[aquacraig@shaw.ca]

I'm glad that there is no obvious answer staring "us" in the face! The solenoid i refer to is activated by the toggle switch on the helm and should then be putting the batteries in parallel and doubling the amps. The switch reads port-parallel-stbd.,so I assume the middle position is "both" but it clearly acts as though I am "paralleling through port" or "paralleling through stbd" with the centre position being "off", or idividual banks. Is this possible?
I'll try to find a pic.

Thanx

Craig

 

[Trojan]

I seem to have something strange happening so need some advice. I normally run, and charge, with my battery switch on "parallel". This has always been fine and I seem to have lots of juice on both 32v banks. Recently, I had a cell go on one battery in the PITA stbd bank so I replaced the lot. After everything was back to normal and batteries fully charged, I monkeyed with the bow thruster and the darn thing turns faster on "stbd" or "port" than it does on "parallel"!
Does this make sense? I thought parallel would theoretically double my amps and give me more power and duration. I know I have 34v on full charge in both banks so why is the "parallel" worse?

Thanx

Craig

The parallel switch Is only a relay in most cases and is not intended to be on 100% of the time. Second is the contacts on the relay are rather small. The big issue most likely is the wire sizes and length of wires going between the two batteries. If they are not large enough They will not carry the load and will lower the voltage between the two on a heavy current draw. With the parallel switch on continuous You stand the chance of burning up the regulators on the generators. You can also do damage to the battery charger. The charger lines are independent and when tied together they will chase each other and cause an overload on the charger. I don't believe the parallel switch was intended to be a true parallel switch , but to be used as a booster not a power switch. I also don't think that the bow thruster is powered off of both banks. Usually its powered off one side and a separate battery bank just for the thruster.
The middle position is off.
BILL

 

[REBrueckner]

aquacraig: Perhaps the solenoid is wired incorrectly...that is, differently than the switch label indicates....that's why I asked the question above, "is this a new situation since you added new batteries".... Did anybody work on the battery cabling to the solenoid?? It's easy to connect things to the wrong terminal when working in cramped quarters, upside down,etc....

 

[SKYCHENEY]

Center position is off, not both. It is a momentary contact to either side for paralleling that engine (port or stbd). That is how I have seen them on most Hatts.

 

[aquacraig@shaw.ca]

Sky, Now that makes sense. I'm sure my thruster and windlass are powered off the stbd bank so I am in fact "paralleling" when I move the switch to port or stbd. Therefore should I leave the switch in the centre position for normal operation?

Thanx

Craig

 

[SKYCHENEY]

Sky, Now that makes sense. I'm sure my thruster and windlass are powered off the stbd bank so I am in fact "paralleling" when I move the switch to port or stbd. Therefore should I leave the switch in the centre position for normal operation?

Thanx

Craig

That is correct. There should be two parallel solenoids, one in each engine room in the aluminum boxes that contain the master battery switches. When you push the button to port, it closes the solenoid in the port ER so that all batteries are connected together in parallel. When pushed to stbd, it closes the solenoid in the stbd ER box.

You can see the solenoid in the top of this box.

 

[aquacraig@shaw.ca]

Sky, I think my Hatt was built before they invented such gorgeous aluminum boxes, but nonetheless, I am going to identify my solenoid(s) now that you have so kindly explained how the system works. I think that where I originally got confused was by listening to an EXPERT who I should have ignored.

Thanx

Craig

 

[Nonchalant1]

If both battery banks have power, there is no difference between "port" and "Starboard" position of the parallel switch. The two positions are there in case one battery bank is completely dead, so it can't even operate the parallel switch. If one bank is completely dead, you move parallel switch towards the other (good) bank to parallel them both. The parallel switch should only be used momentarily to crank up the juice when one side is a little low. That's why it is spring loaded to snap back to "off".

The center position is "off" so it makes sense that the thruster works better in either position. When you run and charge in the center position, the banks are completely separate, being charged and use3d separately.

Doug