AMSOIL Information Series: Exposing the "One Arm Bandit" (6 min 39 sec)

OK for those not interested in the whole thing , this 2s pack sux's !
It's cheap , but nasty ! and just might bite you in the wallet ...


Discharging at 0.5 Amp to 6v I was able to get some 377mAh from this pack !
BUTT !!!!!

There was some serious imbalance between the cells ( Voltage ) .

So repeating the process 2 more times saw no improvement what so ever ..
When the cells hit 3.6 volts the imbalance kicked in ( obviously one cell has less capacity than the other by quite a margin )
Until 3.6v ( 7.2v for pack voltage ) everything is fine , the cells are maintaining a very balanced discharge ..

Butt !!!!!

Once the cells reach 3.6v one cell begins to drop voltage ever more rapidly .
@ 3.58v the other cell reached a low off 3.46v
@ 3.57v the other cell reached a low off 3.35v
@ 3.56v the other cell reached a low off 3v ( I stopped the discharge here )

So while one cell was reaching the almost out of puff point , the other was sucking rust from the bottom of the tank !

I don't for a moment think it would be safe to do anything but balance charge this battery very slowly ..
Can it be used ? If you drain it till the charger calls it quits the bad cell has hit 2.5 volts ...
I just got myself a smaller lighter voltage alarm which needs testing , so definitely I would recommend a voltage alarm set to 3.6v ...
But I really have to call this DUMPSTER good !



So be WARNED ! , it is cheap ( That's good ) but its nasty ( That's bad ) ... So in no way shape or form would I recommend the VOK 480 2s ....

It's

I just got me another VOK battery ( for my Spirit 600mm Wing ) , a 480mAh 2s .
And it really is Rubbish , ( Just started my 2nd Discharge @ 0.5 A )

But it got me thinking about just what makes a high performance battery ?

Is it just the discharge capability ? or are folks putting in a little more effort ?

My thinking on a high performance battery is cell matching ...

1) Match the discharge capability
2) Match the capacity
3) Match the resting voltage

This would require each cell to be tested individually before being made part of a pack ...
Seems some just throw cells together , charge and discharge and if the cells ( by chance ) are well matched and perform well . the pack is called High Performance ... ( ?)

With all sorts of electric racing now the norm , there seems to be a higher and higher demand on the battery pack .. Watching youtube video and telemetry from some high performance quads , some are pulling North of 100 amps , and they are not running 100 amp ratted batteries ..
With that much strain put on battery packs , it really got me wondering just how much effort is going into building high performance battery packs .

( I wonder just how much effort is put into these VOK batteries - if any ) ...

So as I sit here watching the VOK discharge ( and listening to the rain outside ) , batteries are on my mind .
Just watching out for the point where one cell starts to vary from the other ( Voltage ) , as it is an...Continue Reading