After 52 charges the batteries that came with the Matrice 600 have lost 20% total capacity on average, which I think is fairly much! Well have I been hard on the batteries or is the clue somewhere else.

1. Flying around 30 min. on a fully charged battery down to 25% is a discharge rate of less than 2C, which in my view is quite low and shouldn´t be hard on the batteries. Flying 18 min. with max payload is a discharge rate close to 3C. Still fairly low.

2. When the batteries are charged to 100% the cell voltage is 4,35V. If the TB47S is a "normal" lipo battery with a nominal voltage of 22,2V giving a cell voltage of 3,7V the max cell voltage should be 4,2V. If that is the case the battery has the ability to overcharge itself with 0,15V/cell which would be hard for the battery.

3. I don´t have a TB48S battery but I can see that the nominal voltage is 22,8V for the battery which is 3,8V/cell, which would be a "Hi voltage" lipo battery, where the max cell voltage is 4,35V.


Any comments appreciated.

Soren

Greetings Soren,

if the distance you have on you page is 324522 m divided by 52 charges that is 6.24km per outing, I think that is quite an achievement for those batteries. plus you should take into account the standard for temperature v battery charge is done @20ºc and I am sure you don’t charge in a temperature stabilised environment and unless the voltage monitoring systems are calibrated  the readings shown will have a large tolerance factor so that 20% could be higher or lower. The numbers are just guidance unless you have lab conditions with calibrated lab measuring devices.
Only time in the air counts and you seem to have plenty. Maybe look at it from an accountants point of view and remove the emotion of having to buy new batteries especially if you get money for the hours in the sky.

Ricci

Hi Ricci

Thanks very much for your inputs.

Well the point for me is to figure out if I have a bad batch of batteries or if I put unnecessary wear on the batteries in the charging process if I let the battery do the charging cutoff at 4,35V/cell or if it is just normal wear for the battery. As mentioned earlier I don´t think the TB47S is a "hi voltage" lipo battery and therefore should have a max cell voltage of 4,2V.

I have made some charges with another charger which I have calibrated with the use of a calibrated lab voltmeter. If I let the charger cutoff at 4,2V/cell and then have a look in the DJI Go app I also see 4,2V/cell and an approximate 93% charge.

I would say that 98% of my charges have been in a temperature range of 15-21ºC.


Soren

What you do is drain the batteries to 0%,actualy you need to let them turn of byitself,i use phantom 4 addapter and 5v led bulbs i bought on amazon,it takes long time but i get 98-100% capacity.I have 180 tb47/tb48.Sometimes you need to do this more than once.Also after they turn off let them sit around for few hrs.I done this 100s of times and no battery went bad on me.Dont leave them for more than a day.Batteries i have well over 100 charges and they comeback like new specialy if you use them in sets of 6 ,not randomly.I have couple sets 140-150 charges and they give me 40 min with x5.