Back2PA
Well-known member
- Joined
- Jul 26, 2015
- Posts
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Starting the homework to install a second bank of batteries. Unfortunately the closest possible location could have a wire run back to the existing house batteries of upwards of 15 feet by the time I allow slack for battery tray movement, etc. (Could be as little as 10 feet, still working on routing and measurements.) This is not a function of bins that are full of stuff (which of course they are), it's a function of the fact that the closer bins cannot be used for flooded battery storage, e.g., inverter/equipment bin, electrical bin, water bin, etc.
Second battery bank will consist of 4 batteries of similar/identical capacity as the house batteries in the tray: about 480AH. I'm thinking the highest charging current would be battery charger (100A) ? 2 so 50A. The highest theoretical load would be max inverter load (2000W?12V=170A ish) + (other 12V loads so say 20A max) ? 2 = 95A. It seems like this would be the extreme worst case scenario for perhaps 5 min periods at most, with real world load numbers probably half of that. This is my crayon math, so some likelihood my assumptions are way off and/or I have failed to consider other issues.
My plan, once wire routing and length is figured out, is to get the cables made at a welding shop.
My questions:
1) How's my math? What am I missing?
2) Using my/your math, and these approximate distances for now until I get better measurements, about what wire size am I looking at (besides BIG! )
It's occurred to me that the distance and amperage involved may mean double cables but would really like to avoid that if at all possible for both cost and install/routing reasons.
The long-term plan is to add solar, but it seems to me if the super high load issues are handled correctly I will be more than ready to tie-in solar anywhere in the setup.
I'm committed to flooded batteries as my house (flooded) batteries are new. Plan is to place second set in marine battery boxes (found this source: http://batterymart.com for boxes and vent kits). Looks like two of these: http://www.batterymart.com/p-hm426-dual-6-v-battery-box.html would work.
Thx
Second battery bank will consist of 4 batteries of similar/identical capacity as the house batteries in the tray: about 480AH. I'm thinking the highest charging current would be battery charger (100A) ? 2 so 50A. The highest theoretical load would be max inverter load (2000W?12V=170A ish) + (other 12V loads so say 20A max) ? 2 = 95A. It seems like this would be the extreme worst case scenario for perhaps 5 min periods at most, with real world load numbers probably half of that. This is my crayon math, so some likelihood my assumptions are way off and/or I have failed to consider other issues.
My plan, once wire routing and length is figured out, is to get the cables made at a welding shop.
My questions:
1) How's my math? What am I missing?
2) Using my/your math, and these approximate distances for now until I get better measurements, about what wire size am I looking at (besides BIG! )
It's occurred to me that the distance and amperage involved may mean double cables but would really like to avoid that if at all possible for both cost and install/routing reasons.
The long-term plan is to add solar, but it seems to me if the super high load issues are handled correctly I will be more than ready to tie-in solar anywhere in the setup.
I'm committed to flooded batteries as my house (flooded) batteries are new. Plan is to place second set in marine battery boxes (found this source: http://batterymart.com for boxes and vent kits). Looks like two of these: http://www.batterymart.com/p-hm426-dual-6-v-battery-box.html would work.
Thx