Hi All,
New here... Some advice for an affordable LiFePo4 UPS solution please...
I'm dealing with a load shedding situation and have bought a few Lead Acid UPS's, but the batteries don't last.
It's a 230V KSTAR 1000VA UPS with 2 x 7Ah 12V lead acid batteries in series = 24V (pic below).
The load shedding is 1 - 2 times per day, usually 2.5 hrs long. I'm not sure if the almost daily charge cycle is killing the batteries, or if there is not enough time to recharge the batteries (probably both!) I do not know the charge rate, but the manual says 6-8 hours to charge to 90% after complete discharge.
I found these LiFePO4 batteries which are Lead-Acid drop-ins: 13V 11Ah. I connected them and they seem to work great for now.
It has a BMS and advertised for 5,000 cycles, and the charge characteristics are much friendlier.
They are actually 13V batteries, and the spec sheet say they can be a charged to 14.4V = 3.6V per cell (x4) for each 13V pack
The UPS however still thinks I've got the 12V batteries in and floats the batteries at 13.4V x 2 = 26.8V
It correctly disconnects the batteries at about 20V (10V x 2) under load, which I have checked with the manufacturer and they say this is ok.
Although the KSTAR UPS is cheap, I'm not fully utilising the LiFePO4 battery potential: 26.8V instead of 28.8V fully charged (3.6V x 4 = 14.4V)
I'm looking for a (cheap = value) inverter / charger which is programmable: 1) charge voltage, current and float, 2) disconnect voltage, and 3) maybe even a low voltage alarm.
Questions:
1. Can you please recommend an inverter / charger that can do the job?
2. Are there other batteries or total solutions you will recommend? I need to run about 300W of power for 3 hours
Thanks so much!
Eben
New here... Some advice for an affordable LiFePo4 UPS solution please...
I'm dealing with a load shedding situation and have bought a few Lead Acid UPS's, but the batteries don't last.
It's a 230V KSTAR 1000VA UPS with 2 x 7Ah 12V lead acid batteries in series = 24V (pic below).
The load shedding is 1 - 2 times per day, usually 2.5 hrs long. I'm not sure if the almost daily charge cycle is killing the batteries, or if there is not enough time to recharge the batteries (probably both!) I do not know the charge rate, but the manual says 6-8 hours to charge to 90% after complete discharge.
I found these LiFePO4 batteries which are Lead-Acid drop-ins: 13V 11Ah. I connected them and they seem to work great for now.
It has a BMS and advertised for 5,000 cycles, and the charge characteristics are much friendlier.
They are actually 13V batteries, and the spec sheet say they can be a charged to 14.4V = 3.6V per cell (x4) for each 13V pack
The UPS however still thinks I've got the 12V batteries in and floats the batteries at 13.4V x 2 = 26.8V
It correctly disconnects the batteries at about 20V (10V x 2) under load, which I have checked with the manufacturer and they say this is ok.
Although the KSTAR UPS is cheap, I'm not fully utilising the LiFePO4 battery potential: 26.8V instead of 28.8V fully charged (3.6V x 4 = 14.4V)
I'm looking for a (cheap = value) inverter / charger which is programmable: 1) charge voltage, current and float, 2) disconnect voltage, and 3) maybe even a low voltage alarm.
Questions:
1. Can you please recommend an inverter / charger that can do the job?
2. Are there other batteries or total solutions you will recommend? I need to run about 300W of power for 3 hours
Thanks so much!
Eben
Last edited:
then consider going all the way and just charge from solar! Take a look here to get started and come back with more questions.
