Charging up to storage level

[williamjamesfpv]

Hi guys - So, instead of charging my battery 100% and then dropping it down to 50% via flying, I decided to just charge it up to the 50% mark. However, I noticed that by charging only up to the 50% mark, that my cells aren't balanced. For example, 3.85v, 3.84v, 3.87v, 3.86v . I have 3 questions regarding this:

(1) If I am leaving my battery in storage mode, does it matter if there is a minor discrepancy in voltages?

(2) By having a minor discrepancy, does the battery discharge any faster/slower?

(3) When I do decide to finally charge it to 100% (as in after my storage period, and prior to flying), will my cells all balance?

 

[msinger]

That discrepancy is pretty standard. If there is a large discrepancy and the battery is fairly new, then try running the battery in your Phantom until it shuts off and recharge it. That normally rebalances the cells.

 

[williamjamesfpv]

That discrepancy is pretty standard. If there is a large discrepancy and the battery is fairly new, then try running the battery in your Phantom until it shuts off and recharge it. That normally rebalances the cells.

My main concern is whether it will all balance in the end when I'm ready to fly (as in after I come out of storage mode). I'm also wondering if it'll discharge any faster/slower as a result of the discrepancy. My batteries are pretty new (ie: less than 20 charges)

 

[msinger]

My main concern is whether it will all balance in the end when I'm ready to fly (as in after I come out of storage mode).

The cells should be close, but they don't have to match 100%. I don't think the cells will ever auto rebalance themselves. Completely discharging the battery is the only way to rebalance them. In your case, I wouldn't do that since you do not have a large discrepancy. If you would have a large discrepancy and completely discharging and recharging does not fix the problem, then the battery is most likely damaged.

I'm also wondering if it'll discharge any faster/slower as a result of the discrepancy.

Sure -- each cell in the battery will discharge/recharge faster if the full capacity is higher/lower than the next cell. The discrepancy in your battery is minor though. You have nothing to worry about. On a similar topic, it's a good idea to keep an eye on the individual cell voltage when flying.

 

[williamjamesfpv]

I don't think the cells will ever auto rebalance themselves. .

Sorry, but I'm confused. Why would they never rebalance themselves? My cells were all balanced in a discharge state tonight. Then, I went to charge it up to 50% and now they are slightly mismatched. So if I fully charge it to 100% it won't balance itself out now? Please tell me that I've misunderstood you.

 

[msinger]

So if I fully charge it to 100% it won't balance itself out now?

I don't know. Try it and report back. I'm just confirming that you should not be alarmed if the cells do not match 100%. A slight discrepancy is normal.

 

[williamjamesfpv]

I don't know. Try it and report back. I'm just confirming that you should not be alarmed if the cells do not match 100%. A slight discrepancy is normal.

Okay, wanted to report back after I fully charged the battery. My cells are at 4.29v, 4.33v, 4.33v, 4.30v. Does this sound about right for a battery that has less just <20 charges on it?

 

[msinger]

It's an acceptable discrepancy. DJI recommends completely discharging and recharging every 20 charges. When you do that, the cells should balance themselves out. There still could be a slight discrepancy even after doing that, but most people find it at least reduces the discrepancy.

 

[williamjamesfpv]

It's an acceptable discrepancy. DJI recommends completely discharging and recharging every 20 charges. When you do that, the cells should balance themselves out. There still could be a slight discrepancy even after doing that, but most people find it at least reduces the discrepancy.

Ah! I see.... now its all starting to come together. Going back to like all your posts in this thread now. You've been very helpful. Thank you and very much appreciated

 

[Pete Leare]

I agree, msinger is one of the most helpful people on this forum