I have two older 2.2 kW feather batteries (with Anderson connectors and the soft-start switch). Both were put in to storage for the winter at the same approximate voltage (3.7V/cell, ~89V). I just took them out of storage and went to top them up. One is at 77.5V (3.2V/cell) and the other is way down at 11.6V! What did I do wrong? It’s very curious to me that there is a such a difference in the two otherwise identical packs.
I know 11.6V is way low and the cells are likely now toast. Has anyone been able to safely revive cells from such a low state of voltage? Any tips? Any way to prevent this in future?
A few months of storage shouldn’t be an issue. I have some automotive cells that have been in storage for years that have only lost around 0.1V/year.
Even my new v2 battery drains from 50-60% down to dangerous levels within ~2 months - definitely can’t store it all winter without recharging. To reduce the parasitic drain rate, you can adjust the software behavior within the ANT BMS app.
1. Adjust the “Wait Sleep” Time
Navigate to the ParameterSet tab. Look for a setting labeled Wait Sleep or Idle Time.
Action: Reduce this value (e.g., to 600 seconds or 10 minutes).
Effect: This tells the BMS to enter a low-power “sleep” mode sooner when no current is flowing (i.e., when you aren’t charging or using your 3D printing gear).
2. Disable Non-Essential Functions
While in the ParameterSet or BMS Control tabs:
Balance Settings: Ensure “Static Balance” is turned Off. If left on, the BMS will constantly monitor and bleed energy to balance cells even when the battery is just sitting, which significantly increases drain.
Bluetooth Timeout: If available, set the Bluetooth visibility to a timeout rather than “Always On.”
Thanks. Mine have the Daly Bluetooth BMS. I’ll check for similar settings on both of them.
Do you know which ANT BMS is used? I have one older 4.2 kw battery with a non-BT Daly BMS that I’d like to upgrade. I might as well go to the latest and greatest.