I recently bought an inverter that I started using to drain my battery to “healthy” voltage level for long-term storage. One of my batteries – when connected to the inverter with a load on it (floor fan) – shuts off at about 91V.
I don’t think it’s supposed to do that.
I have another battery that behaves as expected. I can connect the inverter and put a load on it, and it powers the load (fan) all the way down to 86.4V without a problem.
What can I do to further diagnose this problem? It seems like trying to fly with it would be unwise.
If you install the 91V battery and get into your harness, will the throttle arm and allow you to run the motor up for several minutes? If it won’t, then you probably have a BMS problem. Will your second battery allow you to run the motor up for several minutes? If your battery has Bluetooth, you should be able to check the string voltages…if not, I would guess you have a string with low voltage, and the BMS is shutting the battery down. That is the very reason that I replaced both of my BMS units with Bluetooth units with soft switches and added Daly active balancers. I had one battery that shut off in flight on 4 different occasions.
You’ll figure it out…process of elimination.
Bill
Thank you so much for these tips. It’s very helpful. I’ll keep investigating. I thought my battery (batteries) had bluetooth, but I’m not seeing them show up in the available bluetooth devices on my phone. I’ll have to look into it more. I’m not sure when they started shipping batteries with bluetooth, so maybe I actually don’t have that.
You need to download the Smart BMS app. It will only show in the app while plugged into the speed controller or charger or within 10 minutes after disconnecting it. You can change the timeframe after you can connect. I set mine to an hour.
To learn more you can do a search on this forum for Smart BMS.
