Off Grid Battery help needed

Hopefulman

New Member
Joined
Sep 28, 2021
Messages
2
I need help in figuring out how to increase my battery bank size. I currently have a 16 battery, KiloVault 2100 PLC battery bank set up 48 volt - 720ah total. Given type of battery I only have 360ah of available capacity. The batteries have been in service 12 months. My home has geothermal heating and cooling and while very efficient the system demands a significant amount of electricity that at times exceeds my battery bank's storage capacity. On the other end of my system the solar panel's ability to recharge the system far exceeds the battery bank's capacity most days having the battery bank up to 95% soc by 11:00 AM so I lose a large part of the charging day. My goal at minimum is to double the size of battery bank but not sure how to move forward; cost and battery type are at issue. Any help would be appreciated.
 

Hopefulman

New Member
Joined
Sep 28, 2021
Messages
2
Yes I am open to LiFePO4

I had hoped I could just double size of existing KiloVault bank but not sure I can go beyond 4 series of 4 batteries not to mention used mixed with new may be an issue.
 

FilterGuy

What, me worry?
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Nov 26, 2019
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Los Gatos CA
I would not try to mix battery types.

You have a fairly big system already. I see 2 approaches. LiFePO4 or More lead acid.

Mixing old and new lead acid is not good, but can be done. To get what you want you would need to double your current LA size.

With LiFePO4 you are looking at 64 280 or 300Ah cells.

The upfront costs are are probably going to be less for LA but in the long term LIFEPO4 will be lower cost.

What do you currently have for inverter charger and solar?
 

time2roll

Photon Sorcerer
Joined
Mar 20, 2021
Messages
2,405
How much is a second set of KiloVault? To build your own LFP in the 48v - 720Ah usable zone is probably $7,000 or so.

If you are thinking to switch you could run the KV a bit harder (60-70% discharge?) while you sort out the new battery.
 

FilterGuy

What, me worry?
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Nov 26, 2019
Messages
4,710
Location
Los Gatos CA
If you decide to go with LA,. You gust put the 2nd series string Parallel with the first string
 
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