LiPo battery IR values

[jayeff]

Hi,

I am new to the RC hobby and did some reading on LiPo batteries before taking the plunge.

I am using a new 2S LiPo 3250mAh Voltz battery which I took the IR readings of both cells after purchasing (at storage voltage 3.8v per cell). The readings were as follows:

12.6mΩ and 13.6mΩ

(thought these were a little high to start with)

After only two charge cycles these values are now reading the following (again at storage voltage 3.8v per cell):

22.6mΩ and 23.6mΩ

Should I be concerned that the IR values have risen this amount after only two charge cycles?

Any advise would be appreciated. Thanks.

 

[bill_delong]

Smaller capacity batteries will tend to have higher IR in general, even higher if they are low C rated packs, particularly budget brands.

You want the initial IR reading to be your baseline and then use your best judgement to determine when the IR is out of your comfort zone.

I try to measure my IR readings right at the end of a full charge cycle to get the best readings. Typically the readings will get better after subsequent charge cycles within the same day.

The absolute worst time to get an IR reading is after the battery has been partially drained, more info here on my opinions with IR with respect to 100C+ packs in the 5Ah+ range:

• Which charger is the best?