kZs0lt
100 W
I am using a CA 2.11 direct plug in and am wondering what is the accuracy on them.
When I first plugged in to the controller, I saw battery voltage rising 1-2 volts in some 10s of seconds. It finally settled down close to what my cheapo multimeter displayed.
This still happens usually, having a warm-up when connected to battery. Sometimes a few tenths of volts, and sometimes several volts. Is this normal?
A few days ago, a rain got me on the bike and after riding about 10 mins in the rain, I got home, parked the bike. Next day when connected my battery, the display showed full bars for a second, then in a few seconds faded into visible characters, and voltage reading started somewhere 54v and slowly increased to 60.x volts after about 1 min, but the battery was 61.5v off the charger (15s LiIon charged to 4.1v/cell)
I know that there is a setting for voltage divider, is set to 23.x, have to check it exactly, but I don't want to mess with that, as I suppose it was precisely calibrated.
On the other hand I had problems calibrating the shunt as well. I don't have a precise ammeter, so I tried to calibrate with my RC charger.
I run the current through the shunt, soldered sense wires to the shunt ends, and charged a cell through it. However it did not seem to be quite linear, If I set the shunt value in CA to show exactly 5.00 amps when charging @ 5 amps(max on the charger), when I set it lower to 1A, it would read something about 0.94A and if discharging, about 1.07A. Is this normal, supposing the charger should be pretty accurate on Amps?
Anyway the no throttle amp display is drifting as well, from 0.05-0.2A, usually higher after a big load. This must be the thermoelectric effect, but should it be so high?
And after calibrating so that on 5 amps it shows just slightly more than 5 and on 1 amp slightly less that 1, I still get my numbers way off. Discharging to 3.7Ah and the charger puts back 4.3Ah, the gap is still way more than the charging efficiency, that's -15%.
Also how do I need to set-up the sense wires and set zero amps in order to record the idle current of the controller as well(around 0.06A)? This is pretty important, because I may leave the controller on, or coast for a significant time slowly draining the battery and I'm not sure this will reflect in consumed Ah and could kill my battery at close to 100% DOD(running with no BMS). Does the controller idle current go through the shunt?
Please let me know if your unit is more precise, I'm not very thrilled with the accuracy for a $100+ device. However this is a great tool, hope I can get it more accurate, please help me calibrate it better.
Thanks,
Zsolt
When I first plugged in to the controller, I saw battery voltage rising 1-2 volts in some 10s of seconds. It finally settled down close to what my cheapo multimeter displayed.
This still happens usually, having a warm-up when connected to battery. Sometimes a few tenths of volts, and sometimes several volts. Is this normal?
A few days ago, a rain got me on the bike and after riding about 10 mins in the rain, I got home, parked the bike. Next day when connected my battery, the display showed full bars for a second, then in a few seconds faded into visible characters, and voltage reading started somewhere 54v and slowly increased to 60.x volts after about 1 min, but the battery was 61.5v off the charger (15s LiIon charged to 4.1v/cell)
I know that there is a setting for voltage divider, is set to 23.x, have to check it exactly, but I don't want to mess with that, as I suppose it was precisely calibrated.
On the other hand I had problems calibrating the shunt as well. I don't have a precise ammeter, so I tried to calibrate with my RC charger.
I run the current through the shunt, soldered sense wires to the shunt ends, and charged a cell through it. However it did not seem to be quite linear, If I set the shunt value in CA to show exactly 5.00 amps when charging @ 5 amps(max on the charger), when I set it lower to 1A, it would read something about 0.94A and if discharging, about 1.07A. Is this normal, supposing the charger should be pretty accurate on Amps?
Anyway the no throttle amp display is drifting as well, from 0.05-0.2A, usually higher after a big load. This must be the thermoelectric effect, but should it be so high?
And after calibrating so that on 5 amps it shows just slightly more than 5 and on 1 amp slightly less that 1, I still get my numbers way off. Discharging to 3.7Ah and the charger puts back 4.3Ah, the gap is still way more than the charging efficiency, that's -15%.
Also how do I need to set-up the sense wires and set zero amps in order to record the idle current of the controller as well(around 0.06A)? This is pretty important, because I may leave the controller on, or coast for a significant time slowly draining the battery and I'm not sure this will reflect in consumed Ah and could kill my battery at close to 100% DOD(running with no BMS). Does the controller idle current go through the shunt?
Please let me know if your unit is more precise, I'm not very thrilled with the accuracy for a $100+ device. However this is a great tool, hope I can get it more accurate, please help me calibrate it better.
Thanks,
Zsolt
