Seeking advice on battery bank replacement

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fgeremia
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My RE system: 6 Evergreen 110 watt panels
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8 Trojan L16reb batteries
Honda eb5000 gas generator
Off grid since 2004

Seeking advice on battery bank replacement

Post by fgeremia »

My 8 Trojan L16re battery bank is due for replacement, and I'll be swapping them out with a LiFePo set from either Relion or Battleborn.

How realistic of a diy job is this for someone with basic electric skills, or is it something best left to a professional?

I've relied on a great installer for the past 18 years, but they retired their business, and I'm thinking that as a builder and fairly competent diy-er it's time to take the reins.

Thanks for any advice
raysun
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My RE system: Flexpower Two: (2) FXR3048A-01, (2) FM80, MATE3s, FlexNetDC
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REC Alpha 440W panels - 2 arrays: each of 4 strings of 2 in series
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Re: Seeking advice on battery bank replacement

Post by raysun »

Swapping to a LiFePo4 battery using "drop in replacement" units like those from Relion and Battleborn is a fairly simple task.

The first step is to plan the capacity needed. The L16reb have 370AH per string, and your battery is two parallel strings for 740AH, with 50% usable = 370AH net capacity. To replace that with LiFePo4 @ 80% usable capacity calls for a 450AH battery. If daily cycling uses less than 370AH, then apportion the new battery accordingly.

Check with the manufacturer about connecting their battery blocks in series and parallel. The ability to do so may influence your choice.

Second step is to plan the physical wiring. It may be tempting to use the existing cables, but LiFePo4 are sensitive to very small voltage variations, and professionally made cables of proper design help assure this is not an issue.

Third step is configuring inverters and charge controllers for proper charging, discharging, and high/low voltage battery protection. The manufacturers specifications, and any integration guides they may publish are important documents for this.

Lastly, initially charging the battery prior to first use. Once this is completed successfully, you are good to go!
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