How can I add power to my older battery bank?
- Thread starter Cullitrel
- Start date
rodrick
Free energy enthusiast
You need to be more specific on what power you are needing more of solar, battery, inverter ect
I'm thinking of a 12v 280ah LifePO4. I'm wondering if, due to the 4 year age of my current batteries, I might need to add it as a separate bank and run my 12v lines off the old ones, using those for the fridge. The new one would be for the inverter to run 110v appliances.
rodrick
Free energy enthusiast
Lifepo is different from lead acid if it was mine I would run the bb’s in parallel and land them on a buss bar along with the 280Ah battery basically a 200Ah and a 280Ah if wired correctly
wpns
Solar Joules are catch and release
As long as they are all LFP, and they’re all 16 cell batteries, you can just put them in parallel.
littleharbor2
Solar Wizard
12 volt system, 4s battery's
As Rodrick mentioned, land them all on a bus bar. Parallel wire the 2 BB's, then, on to the Bus Bars.
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Yes, put them in parallel. But before doing that, I would want to verify the capacity of the existing batteries. If they have significantly diminished capacity then I would not continue using them.
Thanks for the update. For LiFePO₄ batteries with a BMS that you can access through Bluetooth, you can often change the parameters. This would allow you to raise the low voltage disconnect parameter to a value that works better for your system.
I've used a Victron Battery Protect in one of my systems to ensure that one part of the system can't draw the rest of the system down too far. It worked well.
I've used a Victron Battery Protect in one of my systems to ensure that one part of the system can't draw the rest of the system down too far. It worked well.
MisterSandals
Participation Medalist
I would think the BMS saved the batteries from over discharge. However if they were allowed to sit in this discharge state, the BMS can/will eventually over discharge the cells (ironic huh?) and potentially damage the cells.
Can you describe what happened to your batteries?
BB batteries have a 10 year warranty if i recall correctly.
0truck0
Solar Enthusiast
Died, or too low that the charger doesn't know to charge?
I was going to suggest more solar, and it might not be such a bad idea to run a batt system for the fridge, and one for the rest of your camper. My saying is, Fridge is King. You dont want to run bat down from living in camper then the fridge goes dead. However 200 amp hrs of batt are little overkill for a fridge, I assume a DC compressor fridge? That 175 panel should run an avg DC fridge if good sun, and one 100a/h batts would be plenty, so I'd have run the old batts for the camper, and 50 a/h batt, new, for fridge, but 100 to be safe if multiple days in a row of shade.
Whats plan for new batts?
Get one or two batts, not multiples. go big. Get more amp hrs than you need today for tomorrow you likely will need more.
I was going to suggest more solar, and it might not be such a bad idea to run a batt system for the fridge, and one for the rest of your camper. My saying is, Fridge is King. You dont want to run bat down from living in camper then the fridge goes dead. However 200 amp hrs of batt are little overkill for a fridge, I assume a DC compressor fridge? That 175 panel should run an avg DC fridge if good sun, and one 100a/h batts would be plenty, so I'd have run the old batts for the camper, and 50 a/h batt, new, for fridge, but 100 to be safe if multiple days in a row of shade.
Whats plan for new batts?
Get one or two batts, not multiples. go big. Get more amp hrs than you need today for tomorrow you likely will need more.
Apparently the batteries were drained repeatedly, likely causing severe cell damage. I had no idea that a battery with low voltage disconnect still needs a secondary battery protect component at a slightly higher LVD voltage setting . User error. I don't know that BB will deny warranty coverage, but I can't gamble $750 all-or-nothing to find out. Or I suppose I could drive it to Reno ...
Typical recommendation around here is that the BMS is your last line of defense. If the BMS has a low voltage cutoff of 11.0 volts, then inverter should be programmed to cut off at 11.5 volts. That's an example, with made up numbers just to show how to set things.
dopeassjackson
Solar Enthusiast
The problem with useing an inverter for low voltage cut off is even if your wire is sozed correctly you can get voltage sag enough to trip the inverter low voltage cut off.
littleharbor2
Solar Wizard
Good old nuisance tripping
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