I’m not that good in electricity but basically are lithium batteries from power banks would work the same as 12v lead car batteries?
Comment on Switching out UPS batteries
MangoPenguin@lemmy.blahaj.zone 3 days ago
Different chemistry and voltage levels, power banks use Li-ion which is 3.7V nominal per cell, and the UPS needs a 12V nominal battery which you can’t get with Li-ion cells since 3x = 11.1v, and 4x = 14.8v.
However in some UPS models you can replace the batteries with LiFePo4 replacements, as that chemistry does match the voltage and charge profile (at least close enough). If it works or not depends on the UPS and if it complains about the slight differences.
foremanguy92_@lemmy.ml 3 days ago
MangoPenguin@lemmy.blahaj.zone 3 days ago
No they’re different voltages.
foremanguy92_@lemmy.ml 3 days ago
On the paper they are 12v, so what makes the real output voltage
MangoPenguin@lemmy.blahaj.zone 3 days ago
3s would be 11.1v and 4s is 14.8v, so I’m not sure where you got 12v from.
ChaoticNeutralCzech@feddit.org 3 days ago
You need a balancing BMS anyway and the UPS will not be able to charge it to what it thinks is 100% (about 15 V at trickle current) unless you trick it with a resistor (which wastes power of course).
MangoPenguin@lemmy.blahaj.zone 3 days ago
Yeah you need a UPS that’s OK with the BMS charge FETs opening when the battery is full.
ChaoticNeutralCzech@feddit.org 3 days ago
That’s the problem. There will be no trickle current and the UPS will beep because it will detect battery removal.
MangoPenguin@lemmy.blahaj.zone 3 days ago
Some are ok with it, on a thread I saw on reddit awhile ago about LiFePo4, people had reported a few models that worked fine with the upgrade.