[Originally posted on DJI forum, but for obvious reason, DJI didn't like it and so I moved the discussion here]
So I made some modification to the MA2 charging hub to help my batteries last longer…a lot longer, supposedly like 3X longer.
I added a micro controller that monitors charging voltage and stops charging when it hits a preset level and then moves on to the next battery until all 3 batteries are charged to the preset level.
When I am charging to fly, the modified hub would charge to 90% (about 4.25V/cell) only instead of 100% (ie. 4.4V/cell).
It would cut flying time by that much each time I fly but if that translates to increasing number of discharge cycles by about 3X (source: batteryuniversity.com), that's a tradeoff worth taking.
Also, when storing batteries, instead of waiting 10 days for the intelligent self-discharge to kick in, I can set the modified charging hub to charge all 3 batteries to 50% only and stop.
Because I don’t like the idea of leaving batteries fully charged even for 10 days since irreversible damages however small will take place during that time and if repeated over time, it will further shorten life.

The added tactile switch cycles through 50%, 90% and 100% charging modes and the LED lets me know mode selected.

*edit* Adding this table from batteryuniversity.com for those skeptical bunch.
The table is for normal LiPo cell with rated max voltage of 4.2V.
MA2 batteries are high-voltage LiPo with rated max of 4.4V.

So I made some modification to the MA2 charging hub to help my batteries last longer…a lot longer, supposedly like 3X longer.
I added a micro controller that monitors charging voltage and stops charging when it hits a preset level and then moves on to the next battery until all 3 batteries are charged to the preset level.
When I am charging to fly, the modified hub would charge to 90% (about 4.25V/cell) only instead of 100% (ie. 4.4V/cell).
It would cut flying time by that much each time I fly but if that translates to increasing number of discharge cycles by about 3X (source: batteryuniversity.com), that's a tradeoff worth taking.
Also, when storing batteries, instead of waiting 10 days for the intelligent self-discharge to kick in, I can set the modified charging hub to charge all 3 batteries to 50% only and stop.
Because I don’t like the idea of leaving batteries fully charged even for 10 days since irreversible damages however small will take place during that time and if repeated over time, it will further shorten life.

The added tactile switch cycles through 50%, 90% and 100% charging modes and the LED lets me know mode selected.

*edit* Adding this table from batteryuniversity.com for those skeptical bunch.
The table is for normal LiPo cell with rated max voltage of 4.2V.
MA2 batteries are high-voltage LiPo with rated max of 4.4V.

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