I have an UPS with two 12v 7ah lead batteries. If I want to change the batteries I would typically go with lead batteries but here’s my question, can I use some portable mobile batteries to use it?
Because I have a 20000mah inui battery that is rated for 12v at 1.5A is this a good practice to buy several of these (since they are about 20 bucks) disassemble them and use them as ups batteries?
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.
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).
Yeah you need a UPS that’s OK with the BMS charge FETs opening when the battery is full.
When there is no trickle current the UPS will beep because it will detect battery removal.
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.