Hello,
I recently bought one of these KP184s and I've been using it to test Ryobi drill batteries. I have also noticed that occasionally I get spikes, usually downwards, but there have been few upwards also.
Example of downward spike (0A...10A toggling, 15 period):
![Serial to usb on Kunkin KP184 electronic load 2144782-0](https://www.eevblog.com/forum/index.php?action=dlattach;topic=217654.0;attach=2144785;image)
Example of upward spike (0A...15A toggling, 15s period:
![Serial to usb on Kunkin KP184 electronic load 2144788-1](https://www.eevblog.com/forum/index.php?action=dlattach;topic=217654.0;attach=2144791;image)
0A...5A toggling causes periodic spikes?
![Serial to usb on Kunkin KP184 electronic load 2144794-2](https://www.eevblog.com/forum/index.php?action=dlattach;topic=217654.0;attach=2144797;image)
The message checksum is checked, so the data should be OK. I know the checksum is calculated as I spent a while debugging it. The source is available in
https://github.com/korjaa/kunkin-kp184, in case anyone is interested.
I have not inspected the waveform with a scope to verify if the spike is real.Does this happen with a Li-ion battery / LFP battery / DC Power supply discharge tests as well?
Mine are Li-ion batteries, 5s2p
Does this happen with only one specific lead-acid battery or with other ones as well?
Multiple batteries for me.
Update:Tried scoping the waveform, wasn't able to catch the spike during test. I did however noticed that if the load is small 100mA/10mA/0A, there is actual ~2V..3V dip in the voltage occasionally, maybe every 30s. The spike period matches with my earlier 0A...5A toggling test.
![Serial to usb on Kunkin KP184 electronic load 2145031-3](https://www.eevblog.com/forum/index.php?action=dlattach;topic=217654.0;attach=2145034;image)
It does not happen if I disconnect the battery from KP184. The downward slope of the spike is related to the current.
Below are some spike lengths measured with different load values:
Output OFF -- 200ms (happens even with the output off)
8mA -- 1ms...6ms
30mA -- 200us...300us
100mA -- 60us...80us
500mA -- 40us...60us
700mA -- 40us
1A -- couldn't get it to trigger in few minutes.