Voltage drop

[emeraldcoastcamper]

Concerned about my new CATL cells. 12.8 volts and 400 AH.

Ran the camper Microwave for 3 minutes pulling 170 Amps. Voltage read 13.1 prior to the run but dropped to 11.9 during. Went back to 13.1 after the run.
Is this normal? I thought Lifepo batteries would see less of a drop.

 

[Craig]

I am not sure of the spec but that seems reasonable considering 170 amps. for my tests I use Vdrop/amps=resistance 2.1/170=.0070 is right in line with test I have made.

 

[MisterSandals]

Probably just voltage sag. Where and how did you measure 11.9?

 

[emeraldcoastcamper]

Now Cap'n that is a good question. I did not measure at the battery...11.9 was the readout on my Magnum Remote. Of additional concern is the LVDO setting on my inverter...12V. I'm not sure how Magnum calculates this because obviously the voltage is lower under a load than at rest. That's a big hmmmm for me.

 

[tictag]

I'm not sure how Magnum calculates this because obviously the voltage is lower under a load than at rest. That's a big hmmmm for me.

I can only speak from my own experience but my inverter's low voltage disconnect only kicks in after a certain time delay i.e. it does not react to surges. But then 11.9V is below 12V and for three minutes? Definitely on the borderline.