Battery Capacity Test results

[ffrree]

I just done some capacity tests on my VoltaX 100AH Li batteries X 2 in parallel, giving a theoretical 200AH capacity.

I ran down the batteries with a 2000W inverter on a 1 KW halogen lamp. Occasionally, I also run an additional 800W blower for a short period of time.
Here are the results of the final moments of the discharge. At200AH ( @ 86A ), 207.44 AH ( @ 69.6A ) & 207.44 AH ( @83.7 A) and also 207.44AH ( @ 0A ). I could have taken it further to 220 AH and see what happened, but I thought no point in damaging the battery. It has already delivered beyond spec capacity-wise.

I also notice, that while just using my old Pb Acid battery charger, charging them at14A, the charging current would drop to zero once the battery voltage got up to 14.2 V or so. Please comment on this too. And I took that as full capacity for this test. The discharged capacity in the above is counted down from this charge.

Comments, please.

p.s. this is the second test I've done, the first one without capacity meter, just by time and current measurements, it was well within its specified AH capacity.

 

[Pierre]

I just done some capacity tests on my VoltaX 100AH Li batteries X 2 in parallel, giving a theoretical 200AH capacity.

I ran down the batteries with a 2000W inverter on a 1 KW halogen lamp. Occasionally, I also run an additional 800W blower for a short period of time.
Here are the results of the final moments of the discharge. At200AH ( @ 86A ), 207.44 AH ( @ 69.6A ) & 207.44 AH ( @83.7 A) and also 207.44AH ( @ 0A ). I could have taken it further to 220 AH and see what happened, but I thought no point in damaging the battery. It has already delivered beyond spec capacity-wise.

I also notice, that while just using my old Pb Acid battery charger, charging them at14A, the charging current would drop to zero once the battery voltage got up to 14.2 V or so. Please comment on this too. And I took that as full capacity for this test. The discharged capacity in the above is counted down from this charge.

Comments, please.

p.s. this is the second test I've done, the first one without capacity meter, just by time and current measurements, it was well within its specified AH capacity.

Great results ! In my opinion your old LA charger should be fine as I presume that it is not an intelligent charger with a multi stage charge profile.
I trust that the output waveform is flat ( pure DC ) and not a pulsed output. Will be useful to test with a scope.
I am open to correction by the experts on my thoughts.

 

[ffrree]

Great results ! In my opinion your old LA charger should be fine as I presume that it is not an intelligent charger with a multi stage charge profile.
I trust that the output waveform is flat ( pure DC ) and not a pulsed output. Will be useful to test with a scope.
I am open to correction by the experts on my thoughts.

Good point, I shall check that tomorrow with my scope, after 30 years, I still can operate this....the other day to check the output waveform of my pure sine wave inverter. Would it make much difference if the charger is a multi stage charger with pulsated output for Li ?

I am thinking of carrying this charger as my backup whilst traveling on long trips.

 

[Pierre]

Good point, I shall check that tomorrow with my scope, after 30 years, I still can operate this....the other day to check the output waveform of my pure sine wave inverter. Would it make much difference if the charger is a multi stage charger with pulsated output for Li ?

I am thinking of carry this charger as my backup whilst traveling on long trips.

I was mostly referring to mains freq ripple ( 120Hz ) on the output. On a multi stage charger it is important to rather have a LFP charge profile.
On the older LA chargers ( depending on make etc ) the output is quite 'noisy' and not regulated / smoothed properly.