Battery situation for windlass...

Last year I replaced the the 2 T-105's in the starter bank (wired in series for 12 volts) with 2 group 24's (cabled in parallel for 12 volts). The 105's were nearing the end of their life and were having trouble cranking the engine. I had thought that all DC loads were on the house bank but it turns out that the windlass is powered by the starter bank. There is no alternator for the start bank, but it is charged with the Balmar digital duo charge and also with a separate Pro-6 charger on shore or generator charger.

I have a Blue sea battery combiner but typically have it switched to "off" to isolate the starter bank from the house loads. However, I wonder if I should "combine" the banks during windlass operation, which would allow both the alternator output and the house bank to provide extra boost during that situation. I phoned Blue Sea and they said there was not problem using the combiner switch while the engine was running.

Thoughts?




Jim
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I am a little puzzled by your electrical set up.

The Balmar Duo Charger will supply up to 30 amps of DC to charge your starting battery.

Your Blue Sea battery combiner does the same thing. It combines the house battery with the starting battery whenever the house battery is more than about 13.5 volts. It works automatically to do this. When the voltage is below 13.5 volts then each battery is isolated. There is no reason to turn it off.

The two seem redundant.

But if you leave the combiner on all of the time then both your Duo Charge and the combiner will supply current to the starting battery.

Your windlass probably will work fine with just the Duo Charge supplying charging current. Most windlasses draw 60-90 amps and only for a few minutes. The two Group 24s can easily handle that and will get recharged quickly from the Duo Charge.

David

I was thinking the same thing as David....sounds redundant. My understanding of the Blue Sea ACR is that it drops off when the house bank (master bank) voltage drops below a certain level lower than 13.0V. Same with the DuoCharge.

I don't have one of these, but it's my understanding that the Blue Sea ACR shares charging current when available and the House bank is sufficiently charged to the 13+ V. The loads on the Start batt are not shared through the ACR or the DuoCharge units with the House bank...only the charge, unless the "combine function" is used to allow the banks to share the start load. (See the note at the bottom of this page of specs. https://www.bluesea.com/products/7610/SI-ACR_Automatic_Charging_Relay_-_12_24V_DC_120A)

I have a Yandina Combiner and it has provisions for a remote switch for Auto/Off/On. The Auto position if the default if no switch is installed and allows the combiner to tie the banks only when the charge is present and voltage parameters are met. The OFF position defeats the combiner and prevents its connecting the banks when charge is present, regardless of voltage. I use this when I don't want the charge shared with the start battery (e.g. the house needs a charge and the start is full). The ON position overrides the units parameters and allows the banks to combine with or without charging present. This is essentially the same as placing the battery switch to ALL. Both batteries will share the charge current as well as the house and start loads.

What's the advantage to having a Balmar Duo Charge and a Blue Sea ACR on the same pair of banks?

David and I have been chatting about this. It seems the Duo charge isn't working properly and I was overly cautious about the battery combiner as I was concerned I might drain my starter battery. I didn't realize it had charging capability.

Jim


Jim
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