Author Topic: Charging house bank and start bank from charge controller  (Read 462 times)


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Charging house bank and start bank from charge controller
« on: August 30, 2017, 08:07:06 PM »
My coach has four 6VDC house batteries series/parallel providing 12VDC to the house loads. I also have two large 1100ah 12VDC batteries in parallel for starting the diesel engine. Both banks are charged by either the 110VAC smart charger or the engine alternator through an isolating solenoid that either separates the banks or combines them for charging or power distribution.

I want to relocate the house bank of 6V's to another bay closer to where I plan to install the CC and inverter, but about 12 feet forward of the start battery bank.

Will the Classic CC be able to charge both banks - or do I need to do something to "equalize" the two banks - especially given the difference in distance between the CC and the two banks.

I would be OK if all I can charge is just the house bank as the start batteries get little use but get charged on shore (or generator) power, so there is little risk of them discharging in normal operation.

Interested in how this is addressed on other coaches.



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Re: Charging house bank and start bank from charge controller
« Reply #1 on: August 30, 2017, 10:11:05 PM »
Are you going to be putting in solar to charge your batteries ?
It would be tough to charge both batteries with one charge controller since they are different kinds of batteries starting type and deep cycle ?  There may be other ways to trickle charge the starting batteries  from you main battery bank but you should just plan on isolating the systems as far as charging. 

system one
Classic 150 , 5s4p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system two
Classic 150 ,5s 135 watt Kyocero , 16s Calb 100AH LiFePO4 , Outback VFX 3648 inverter
system three
Midnite KID MPPT 24 DC in to  12 volt AGM batterie


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Re: Charging house bank and start bank from charge controller
« Reply #2 on: August 30, 2017, 10:33:36 PM »
Thanks Larry, that makes sense.


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Re: Charging house bank and start bank from charge controller
« Reply #3 on: October 04, 2017, 03:13:00 PM »

I know of only one charge controller suitable for this application and that is:

Morningstar SunSaver Duo model # SSD-25.       This charge controller is meant for dual battery installations. It charges only one at a time. When it is finished charging the first bank then it charges the second bank.
Bank selection is user settable. You cannot select different profiles for main and house lighting.
I have used several of these but my main concern is the house lighting battery so I set the parameters for that bank. That is where most of my use is. The motor starting battery only will need a float charge in my case. I have installed several in friends motorhome  and have had no issues. Generally I use 1-3 100 watt "12 volt panels" with this controller.

« Last Edit: October 04, 2017, 03:17:46 PM by tecnodave »
#1 Classic 150 12 x Sharp NE-170, 2S6P, 24volt L-16 Rolls-Surette S-530, MS4024 & Cotek ,  C-40 dirv.cont. for hot water
#2 Classic 150 12 x Sharp NE-170, 2S6P, 24 volt L-16 Interstate,Brutus Inv.
#3 Kid/WBjr 2 Suntech 280 24v AGM 105 a.h. Exeltech Inv.
#4 Kid/WBjr 2 Suntech 280 12v AGM 105 a.h.


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Re: Charging house bank and start bank from charge controller
« Reply #4 on: October 05, 2017, 09:50:13 PM »

So the BIG question IS !! How many Watts of Panel ? because of math 25Adc with a PWM CC is alot of panels

As Above  VOC is what to watch on a 12Vdc CC .
« Last Edit: October 05, 2017, 09:59:27 PM by CDN-VT »
Canadian Solar 350W 37.6 VOC  30.6 VMP 8.22 ISC 7.87 IMP ,-15 c +30c max  4 strings in 2 in Series for 24v Classic 150 -1020 Ah  Freezers & fridges ~~~ Second Array same panels of 3sx3 parallel for 24 V Classic 150 -440 Ah Outback Barns & out blds.
48Vdc almost done,11Strings up of 3s11P same panels


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Re: Charging house bank and start bank from charge controller
« Reply #5 on: November 20, 2017, 11:22:33 AM »
The SunSaver Duo has a couple settings for  priority charging.

DIP Switch 3 – Battery Charging Priority Select the percentage of available charge current to each battery. 
The 90% / 10% priority setting allows Battery #1 to receive 90% of available charging current, while Battery #2 receives 10% of charging current. This setting is ideal for RV and boat systems where a “house” bank requires most of the available charge current and a separate engine starter battery requires only a “trickle charge” to remain topped-off. When Battery #1 reaches full charge, more charge current will be diverted to Battery #2 as needed.
The 50% / 50% priority setting splits available charge current equally between two battery banks. This priority setting is ideal for systems with two equal-sized battery banks that require simultaneous charging. If one battery bank reaches full charge before the other, more charge current will be diverted to the lower stateof-charge battery. DIP Switch 3 OFF:   90% / 10% Priority (factory pre-set)   DIP Switch 3 ON:   50% / 50% Priority
12 Suntech 175's
   Classic 200
   Bogart Tri Metric
   Trace SW 4024 (brand new, sort of, first energized Feb. 2015)
   8- Alcatel-Lucent 175 ah @ 24 volt AGM Battery bank