Mixed bank charge profile suggestions

[TomW]

I have a mixed battery bank 1260 AH at 24 volts:

Set A:
Approximately 3 year old DeKa C series 450 AH flooded traction battery, 12) 2V cells in a can.



Note the wiring has been upgraded from the day this was taken when it was installed.

Set B:
GNB sealed 810 AH @ 24 volts traction battery,Used purchased for scrap lead price 2 years ago manufactured in Oct. 1999. Was a 36 volt pack but had bad cells so I high graded them and recycled the dogs. The model # is KJB27B090

I have been just using them paralleled with breakers to isolate them so I can EQ the flooded ones occasionally.


####################################

Questions:

What do folks think is a good charge profile for these while in Parallel?

Any suggestions on how or if I should separate them  to float and absorb?

Any general advice / comments?

Until last December, I really did not have enough charge sources to really keep them properly charged and I equalized the flooded set with a grid charger. We added 1500 watts of solar and a classic to the 850 watts of solar and 2 turbines and now I can regularly get the entire pack up to 30 volts no problems on "good" days.

I have noticed the GNBs are slowly but surely improving as I shove more amps into them.

Any suggestions / comments appreciated.

Thanks.

Tomw

[Westbranch]

Tom, my inclination would be another CC or a Blue Sea 3 way marine switch. Issue to watch is you are mixing AGM and FLA's.

[Volvo Farmer]

Everything I have ever read about big lead acid batteries says that parallel strings are an invitation for trouble. Even folks with the same type and age of battery will eventually see imbalances in the strings. I do not believe it is recommended to even mix old and new batteries of the same manufacturer and capacity so in my mind, mixing dissimilar banks of FLA and SLA batteries in parallel is a pretty bad idea.  I think the only way to charge those banks correctly would be as Westbranch recommends.

[Westbranch]

Tom, just thinking about my 2 different AGM's and their charge profiles are similar enough that one would work on the other, but not optimally, let alone if they are 2 different types, AGM and FLA... so I am really leaning toward 2 controllers... you would have to be resetting the C every time you change banks.

Hell i have 2 controllers with 2 identical banks, MX 60 and CL150... the decision is do I add a Lite or a 150??

hth
Eric

[dgd]

I have a mixed battery bank 1260 AH at 24 volts:

Questions:

What do folks think is a good charge profile for these while in Parallel?

The profile you are using now, probably that for the wet 450Ah bank

Any suggestions on how or if I should separate them  to float and absorb?

Keep them as they are now, the acid batteries are ok and the sealed set are recovering, you are doing good with the EQ.

Any general advice / comments?

Until last December, I really did not have enough charge sources to really keep them properly charged and I equalized the flooded set with a grid charger. We added 1500 watts of solar and a classic to the 850 watts of solar and 2 turbines and now I can regularly get the entire pack up to 30 volts no problems on "good" days.

I have noticed the GNBs are slowly but surely improving as I shove more amps into them.

Any suggestions / comments appreciated.

Keep doing what you doing now. Getting concerned about different floats and absorbs is all too complicated and is  probably not worth the effort or expense. If the two banks were near new then maybe so BUT for these not so. 

dgd