- Capacity and BMS shutdown test -
battery was fully charged to 100%, then left the charger connected over night . . . till 0A was drawn - battery 100%
HERE IS THE SETUP, 1x charge battery, connected to a current shunt. - to meter out the Ah drawn.
1x Victron 800va inverter
1x 240v main dehumidifier.
1x 240v pool pump
1x 240v heat gun
we start the test 13:15hrs and start ramping up the loads . . . . 26A at this point.
we keep adding loads till we get to about 47A - that's maxing out the inverter now, so 800W ish.
this is the bits to look at:
Orange is the Current being drawn from the battery - here its 46.6A
the Yellow is the drawn power over time - here 11.4AH... battery is rated for 100AH,. also the time 0:22H (so 20mins)
(ignore the WH reading as that ties in with the Volts and i didnt have that connected)
here we can see the data . . .
left is the POWEROAD APP, middle the Victron inverter, right is the BM2 unit.
drawing 47A flat out . . . . an hour later we have this.
battery showing 65% left, 12.9V.
the thermals are great the battery isnt even warm to the touch . . .
...
by 15:10hrs (almost 2hours drawing 47A flat) we have this.
battery 31% left @ 12.8v
..
by 15:25hrs we are down to 20% @ 12.7v
the meter is still showing the 47A being drawn for 1:59hr
the BM2 is showing the gradual drop in voltage due to the 47A being pulled from the battery.
by 15:40hrs we are at 10% @ 12.5v (thats 2.5hrs ish pulling 47A !!! )
by 9% battery we hit the 100AH drawn mark - that the rated battery capacity.
but i keeps going. . . . . . . still pulling 47A.
15.47 we hit 5% @ 12.4v on the battery monitor APP...
Things start to drop drastically fast from this point.
The battery voltage is dropping fast and the current is ramping up to compensate - but is still going.
15:52hrs we hit 1% . . 47A @ 12.0V
you can see the BM2 voltage graph dropping across the screen.
...
1554 its now 0% 50A 11.7v - the inverter shut down due to the low voltage alarm.
i switched off the inverter LVD and carried on.
16:00hrs . . . 0% 10.98v and still going.
16:04hrs . . . . the power to the battery terminals cut out. - but the battery APP was still live.
we had a "cell low voltage alarm "
the voltmeter test showed we had the 2v monitor voltage at the terminals and the battery was effectivly in sleep / protect mode.
forcing the battery to come back to life again . . .
we had the final result.
battery capacity 113AH - 113% of rated spec.
runtime @ 47A - 2hours and 51mins !!!!!
that's just awesome - !!!!!!
the BMS LVD is set to 10V . . . . . but we didnt get there . . . . yet.
it was the cell balance monitor that cut the BMS out as we was drawing a large load for a lon time.
im sure that if we pulled a lesser load that the cells would stay in balance, then allowing all 4 to drop together and got max capacity out down to the 10V whole battery shutdown.
Notes..
The battery would come back to life after a short while when in cell LVD alarm mode - when cell voltage recovered. (while blue leds on)
when cell or battery was too low the battery went into sleep mode. (all leds off)
Things went south very quickly below 5% SOC - but id be happy to run down to 5% if needed.
The battery will protect itself below 0% with the BMS
for a high cycle count and long lifetime is say 10% is a good lower limit to go to.
the battery didn't even get warm drawing 50A for 3hrs.
ill have to hook up the 1500W inverter to start testing a 100A load to check for heat build up.
so far very happy with this battery.
it pouch cells and super lightweight compared to the Green Lifepo4 battery that has the 18650 cells.
I sent it to a ski buddy who is an accountant
