Finally did a system capacity test... my supposed 310's are really 280's... shocker

[BretS]

Finally got around to capacity testing my 310Ah cells I got from Exploric Energy on Alibaba (link below). These are installed in my system in my 5th wheel with a REC Active BMS. I charged my batteries all of the way up, disconnected all charging, and set my 15K air conditioner on 72F. It drew over 1700W for over 6 hours. Total consumption on the VRM was 11kWh when the inverter shut down on low voltage. The good news is that nothing got hot and the system performed great for the duration. Bad news, as I expected, is the 310's are actually 280's... But, for the price I paid, I am not really disappointed. Instead of 930Ah, I have 850Ah for $1400... Because I did it all myself, I have less in my entire system, including 2100W of panels, than 8 Battleborne batteries cost... I consider that a win!

Eu Gre Stock Exliporc Ev Lf280k 3.2v 304ah Lifepo4 280ah Cell Battery Grade A 6000cycles Akku Lithium 280 Ah Lifepo4 Prismatic - Buy Lifepo4 Cell 280ah 3.2v Lithium Ion Batteries lifepo4 Zelle 280ah Akku catl 304ah Lifepo4 Cell Basen Product on Aliba

Eu Gre Stock Exliporc Ev Lf280k 3.2v 304ah Lifepo4 280ah Cell Battery Grade A 6000cycles Akku Lithium 280 Ah Lifepo4 Prismatic - Buy Lifepo4 Cell 280ah 3.2v Lithium Ion Batteries lifepo4 Zelle 280ah Akku catl 304ah Lifepo4 Cell Basen Product on Alibaba.com

www.alibaba.com

 

[chrisski]

That's amazing for a 12 volt system. How is your battery setup? Appears it is two 12 volt batteries 3P4S.

I wonder what the difference would be on a .2 C test. Did that with 25 ah battery with a 2.5 VDC cutoff, and the batteries shut off around 24.6 ah with a 1.6% difference between high and low cells.

I hated to capacity test my small batteries with a .2C charge. For my 280 ah cells coming in, I think the max my battery tester can do is about 180 watts, the max amps is 20 amps, and that is 24 hours per cell, with a 10 amp power supply that will take 28 hours to fill the battery up. That is 18 and a half days to do a capacity test, if I'm perfectly efficient, which I'm not.

 

[BretS]

That's amazing for a 12 volt system. How is your battery setup? Appears it is two 12 volt batteries 3P4S.

I wonder what the difference would be on a .2 C test. Did that with 25 ah battery with a 2.5 VDC cutoff, and the batteries shut off around 24.6 ah with a 1.6% difference between high and low cells.

I hated to capacity test my small batteries with a .2C charge. For my 280 ah cells coming in, I think the max my battery tester can do is about 180 watts, the max amps is 20 amps, and that is 24 hours per cell, with a 10 amp power supply that will take 28 hours to fill the battery up. That is 18 and a half days to do a capacity test, if I'm perfectly efficient, which I'm not.

It is a 12V 3P4S bank, it is just arranged to save space.

 

[chrisski]

Thanks for sharing. Do you have a BMS on that?

 

[cinergi]

Finally got around to capacity testing my 310Ah cells I got from Exploric Energy on Alibaba (link below). These are installed in my system in my 5th wheel with a REC Active BMS. I charged my batteries all of the way up, disconnected all charging, and set my 15K air conditioner on 72F. It drew over 1700W for over 6 hours. Total consumption on the VRM was 11kWh when the inverter shut down on low voltage. The good news is that nothing got hot and the system performed great for the duration. Bad news, as I expected, is the 310's are actually 280's... But, for the price I paid, I am not really disappointed. Instead of 930Ah, I have 850Ah for $1400... Because I did it all myself, I have less in my entire system, including 2100W of panels, than 8 Battleborne batteries cost... I consider that a win!

Eu Gre Stock Exliporc Ev Lf280k 3.2v 304ah Lifepo4 280ah Cell Battery Grade A 6000cycles Akku Lithium 280 Ah Lifepo4 Prismatic - Buy Lifepo4 Cell 280ah 3.2v Lithium Ion Batteries lifepo4 Zelle 280ah Akku catl 304ah Lifepo4 Cell Basen Product on Aliba

Eu Gre Stock Exliporc Ev Lf280k 3.2v 304ah Lifepo4 280ah Cell Battery Grade A 6000cycles Akku Lithium 280 Ah Lifepo4 Prismatic - Buy Lifepo4 Cell 280ah 3.2v Lithium Ion Batteries lifepo4 Zelle 280ah Akku catl 304ah Lifepo4 Cell Basen Product on Alibaba.com

www.alibaba.com

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Oh hey, you're on here, too! (I replied to your FB post)

 

[Bud Martin]

'It drew over 1700W for over 6 hours. Total consumption on the VRM was 11kWh when the inverter shut down on low voltage."
Is the Watt reading reported from the AC output side or the DC input side?

 

[BretS]

Thanks for sharing. Do you have a BMS on that?

You're welcome! Yes, a REC active BMS.

 

[BretS]

'It drew over 1700W for over 6 hours. Total consumption on the VRM was 11kWh when the inverter shut down on low voltage."
Is the Watt reading reported from the AC output side or the DC input side?

the total consumption has a breakdown showing it all coming from the battery, so I assumed it was DC input. The dashboard has AC loads from the Multiplus, total discharge from the battery (from the shunt), and a calculated DC loads reading.