Leeds
Solar Enthusiast
- Joined
- Jul 7, 2022
- Messages
- 179
October 2022
This Chinese FEENCE branded battery is available on Amazon for $279 with free shipping. For comparison Weize is currently $300, AmpereTime is $350. In the weeks since my purchase there is a new slightly cheaper battery by “IOD” that is selling for $259 but someone else is going to have to try that one out this is currently the only cheap LiFePO4 I need.
The reason I was looking for the cheapest battery was that I intend to push this one to its limits over the winter debugging my freeze protection logic. This battery will spend the snowy winter outside as I determine the proper ratio of insulation to heating. I don’t expect to kill the battery, part of the system is a bistable relay cutting off the solar panels that the controller can hit as a last resort if the cold wins the battle over stored joules. That said, I didn’t want to spend more than I had to for a battery I’ll be destroying if I end up getting something wrong over the next few months. ?
To be honest, I expected the FEENCE to be low quality, probably used parts, etc. And the misspelling on the sticker on the side is something that didn’t instill all that much confidence - “Don’t short circuit the terminals with any ‘Matals.’” But to my surprise this FEENCE battery actually seems to meet specs.
I have gone through a few charge and discharge cycles and I’ve been very pleased with the data. I drained it at about .15C (as I don’t have a tool that can pull more amps) but that test showed the battery to be 106.7Ah when it hit the 10.5v cutout. I did a second capacity test at an even lower C rate somewhere around 0.1C or 10A on this battery and it came out at 107.3Ah which seems very reasonable to me as well.
I also left the battery over a weekend while fully charged and sitting on a shelf. On Friday morning I took the battery off the system as the charge controller had stopped putting amps in and the battery measured 14.6v. Over the next 5 disconnected hours the voltage only dropped to 14.11 and three days later it had dropped all the way down to 13.84v, still slightly higher than I’d expected. This battery doesn’t seem to sag when left alone.
Now the downside- I was a bit concerned when the battery started bulging about the middle after the first few thermal cycles. But the plastic case seems to be pretty thin and it seems likely that the inside foam was just compressed a bit too much and they won out against the thin sidewall the first or second time the battery was warmed by the sun. Both capacity tests were run after this bulging and I have since shrugged it off entirely as a thin-walled packaging issue, not a cell-swelling issue.
The info on Amazon suggests that this battery has a 100A BMS, can be run in up to 4s8p configurations and can be discharged at 1C. I won’t comment more on that stuff as I’m not cutting into this one any time soon to verify any of it. But it does seem to boast of all the stuff one would want them to boast about except of course freeze protection.
If this battery fails on its own I’ll let you all know but so far it’s been a more pleasant experience than I was expecting. After two weeks I give it a solid A.
This Chinese FEENCE branded battery is available on Amazon for $279 with free shipping. For comparison Weize is currently $300, AmpereTime is $350. In the weeks since my purchase there is a new slightly cheaper battery by “IOD” that is selling for $259 but someone else is going to have to try that one out this is currently the only cheap LiFePO4 I need.
The reason I was looking for the cheapest battery was that I intend to push this one to its limits over the winter debugging my freeze protection logic. This battery will spend the snowy winter outside as I determine the proper ratio of insulation to heating. I don’t expect to kill the battery, part of the system is a bistable relay cutting off the solar panels that the controller can hit as a last resort if the cold wins the battle over stored joules. That said, I didn’t want to spend more than I had to for a battery I’ll be destroying if I end up getting something wrong over the next few months. ?
To be honest, I expected the FEENCE to be low quality, probably used parts, etc. And the misspelling on the sticker on the side is something that didn’t instill all that much confidence - “Don’t short circuit the terminals with any ‘Matals.’” But to my surprise this FEENCE battery actually seems to meet specs.
I have gone through a few charge and discharge cycles and I’ve been very pleased with the data. I drained it at about .15C (as I don’t have a tool that can pull more amps) but that test showed the battery to be 106.7Ah when it hit the 10.5v cutout. I did a second capacity test at an even lower C rate somewhere around 0.1C or 10A on this battery and it came out at 107.3Ah which seems very reasonable to me as well.
I also left the battery over a weekend while fully charged and sitting on a shelf. On Friday morning I took the battery off the system as the charge controller had stopped putting amps in and the battery measured 14.6v. Over the next 5 disconnected hours the voltage only dropped to 14.11 and three days later it had dropped all the way down to 13.84v, still slightly higher than I’d expected. This battery doesn’t seem to sag when left alone.
Now the downside- I was a bit concerned when the battery started bulging about the middle after the first few thermal cycles. But the plastic case seems to be pretty thin and it seems likely that the inside foam was just compressed a bit too much and they won out against the thin sidewall the first or second time the battery was warmed by the sun. Both capacity tests were run after this bulging and I have since shrugged it off entirely as a thin-walled packaging issue, not a cell-swelling issue.
The info on Amazon suggests that this battery has a 100A BMS, can be run in up to 4s8p configurations and can be discharged at 1C. I won’t comment more on that stuff as I’m not cutting into this one any time soon to verify any of it. But it does seem to boast of all the stuff one would want them to boast about except of course freeze protection.
If this battery fails on its own I’ll let you all know but so far it’s been a more pleasant experience than I was expecting. After two weeks I give it a solid A.
