question about 1s batteries

[umox]

quick question about 1s 380mah lipo

when charged with the pl8 on the small lipo balance charged setting does not matter if i charge 1 lipo at a time or all 4 together at 1c they all show fully charged 4.2v after cycle is complete.

however once inserted into my hubsan x4 within 5-10secs of flight the lights start flashing to indicate low battery and it powers off with a few flashes at first i thought dead lipo then the same in the other and the 3rd and 4th
but if i charge with the supplied usb cable then all is ok and i get the normal flight time of a few mins before the lights start flashing to indiate low power

i have tried different settings on the pl8 i have discharged, charged, cycle charged but everytime i try to use them its no good.

can anyone shed any light on the situation as charging 1 at a time with the usb is pretty much a killer for the little fellow.
cheers

[Mark_T]

Does the PL8 show a reasonable result for the mAh put into the packs?

[myxiplx]

How long are they charging for on the PowerLab, how many mAh is it reporting at the end of the charge, and if you leave the batteries for a few minutes what voltage are they showing?

It does sound like they're not charging fully on the PowerLab. And are you selecting the 1C charge rate, or manually setting the appropriate current for the packs?

My guess is that you're selecting the 1C charge rate and it's charging them at too high a current, and consequently cutting off far too early. The "1C / 2C / 3C" settings rely on a bit of intelligent guesswork in the powerlab, and depend on the pack it measures. These tiny packs probably have a far higher IR than larger LiPos, and my bet is that it'll struggle to auto-sense the current needed on them.

[kenny d]

You don't have to balance 1s batteries , if you had a 3s bat then it would ballanced the 3 cells , as you only have 1 cell you cant ballance it , on my pl6 I would use #5 preset channel wich is 1s/2s small non ballanced , if you charge 6 batteries at once you still only put in 380mah & how many bats you have on to charge , the pl8 will work out the total mah input , if you put in the total mah of the six batteries (2,280) & then tell it it has 6 batteries it will charger at 6c ie 13,680mah therefore over charging The bats , Hope this helps. , kenny d

[Mark_T]

Depends if he is using a series harness or not I guess...?

If he is then he would balance them as they become a 4S 380mA pack from the chargers perspective.

[umox]

Hi guys been away for a few days hence no reply.
Last battery I charged was just the 1 and charged non balanced setting at manual 380 not 1c setting.
It put in 200 mah and was showing 3.8v at start and took just under an hr and it worked was showing 4.2 on the tester.
I will try doing all 4 again together and see how it works on the same settings as last time.
1 thing I noticed was the internal resistance was rather high at 174! Not sure what this number should be but no puffing and cold to touch while charging.

[Mark_T]

1 thing I noticed was the internal resistance was rather high at 174! Not sure what this number should be but no puffing and cold to touch while charging.

I wouldn't consider your charger as 'accurate' when measuring the IR on such a small battery, but if it is right that would suggest it is a 10C pack which probably isn't far from the truth.

Putting 200mAh into a 380 pack that was at 3.8V sounds about right.