Dual Battery Mod

[shockwave199]

Bingo Bango! I'm an idiot. Muscle memory of doing LiHV Balance got me. Thanks again.

Kind of a bump. I'm interested how fully charging a p3 on a charger works out, and if you notice better p3 behavior in which it no longer jumps into charge mode during startup before fight.

 

[Ed209]

Kind of a bump. I'm interested how fully charging a p3 on a charger works out, and if you notice better p3 behavior in which it no longer jumps into charge mode during startup before fight.

Well I tried it with 2 of my older problem batteries this evening. One battery has 38 flights on record and is 1yr old. DJI charger stopped and I measured the voltage of it with a meter. 17.3v. Popped on my lipo charger and let it do it's thing. When it shut off I powered it on and tested with a meter. 17.3v. I flew the battery right after and DJI Go was showing voltages in the ballpark of 4.30ea. I also measured voltage when the Lipo charger is topping off the DJI battery. Mine was pumping in 17.4v.

 

[Ed209]

I'm not sure if using another charger will work with batteries that have been reporting below 100% capacity consistently. The older or more abuse batteries that I have consistently start with 96-98%. You'd have to think capacity has taken a hit and there's no way to get them up to 4.35v per cell. Maybe I'm wrong?

 

[Deleted member 27337]

Well I tried it with 2 of my older problem batteries this evening. One battery has 38 flights on record and is 1yr old. DJI charger stopped and I measured the voltage of it with a meter. 17.3v. Popped on my lipo charger and let it do it's thing. When it shut off I powered it on and tested with a meter. 17.3v. I flew the battery right after and DJI Go was showing voltages in the ballpark of 4.30ea. I also measured voltage when the Lipo charger is topping off the DJI battery. Mine was pumping in 17.4v.

If you just let the DJI charger charge the battery and pop it in, will the voltages be below 4.30ea?

 

[Ed209]

If you just let the DJI charger charge the battery and pop it in, will the voltages be below 4.30ea?

For that battery that I tested. They were around 4.29 - 4.32.

 

[Deleted member 27337]

I know my B6AC v2 charger puts out 17.49v which is as close to 17.5 as I can get. When I topped my battery off on my 17.32v dji charger, moving it to my 17.35v charger pushed more juice into the battery. If I top them off on my B6AC v2 and pop them in, they show as 100% and 4.33/4.34 per cell in DJI Go.

 

[Deleted member 27337]

If I use my DJI charger only the battery shows as 98% and 4.28 per cell.

 

[Ed209]

I know my B6AC v2 charger puts out 17.49v which is as close to 17.5 as I can get. When I topped my battery off on my 17.32v dji charger, moving it to my 17.35v charger pushed more juice into the battery. If I top them off on my B6AC v2 and pop them in, they show as 100% and 4.33/4.34 per cell in DJI Go.

You're just using the preset LiHV 4S 15.2v preset program right? I'm charging another battery right now on it that was discharged to 50%. I'm curious to see what a normal charge does vs topping off.

 

[Deleted member 27337]

You're just using the preset LiHV 4S 15.2v preset program right? I'm charging another battery right now on it that was discharged to 50%. I'm curious to see what a normal charge does vs topping off.

Yup LIHV Charge 4S @ 5.7A.

Try to top the battery off on the DJI charger, pop it in and look at the numbers, then top it off on the lipo charger and pop it in and see if the numbers are higher

 

[Ed209]

Yup LIHV Charge 4S @ 5.7A.

Try to top the battery off on the DJI charger, pop it in and look at the numbers, then top it off on the lipo charger and pop it in and see if the numbers are higher

That's what I did with the first 2 batteries I tried. I noticed my lipo charger doesn't pump 17.5v when I tried to top them off.

I popped this 3rd bat on at 50% and I watched it ramp up voltage but never got up to 17.5v. Right now sitting at 16.87v and 88%. It's creeping up though...

 

[Ed209]

Almost done. Stepping down amperage and voltage holding at 17.4v.

 

[Deleted member 27337]

I think I confused you by not explaining it right.

The 17.49v output I measured was at the banana plugs while the battery is charging. I only plugged them in halfway so enough was exposed to measure the charging output voltage of the lipo charger.

 

[Silverwingflinx]

Almost done. Stepping down amperage and voltage holding at 17.4v.
View attachment 62450

Yes I have been trying the same thing to!

 

[Ed209]

View attachment 62453

I think I confused you by not explaining it right.

The 17.49v output I measured was at the banana plugs while the battery is charging. I only plugged them in halfway so enough was exposed to measure the charging output voltage of the lipo charger.

 

[shockwave199]

Really I'm mostly concerned that my battery isn't fully charged with the dji charger. Simply turning the battery on after the lights go out will jump it back into charge on the dji charger? I guess I can do that at least, in the mean time.

 

[Ed209]

Ok so it finished. Measured with my meter and reads 17.30v.

Here's what Go says...

 

[Deleted member 27337]

@Ed209 I see your charger puts out 17.36v while charging. I bet if it put out 17.49v it would top the battery up even higher.

 

[Silverwingflinx]

Ok so it finished. Measured with my meter and reads 17.30v.

Well I see a newer battery only 7 charges! And only charging up to 4.31 volts.kinda disapointing for a new battery?

 

[Ed209]

4.35v X 4 = 17.4v and your battery measures 17.3v. I know you can squeeze more juice into that battery

I don't know man... You think there are some variances in our chargers?

 

[Deleted member 27337]

I don't know man... You think there are some variances in our chargers?

I see yours measures 17.36v at the banana plugs and mine measures 17.49v so there could very well be!