G'day folks,

I just picked up GNB 1300 6S and noticed a lower 1st cell IR on both.  Is this an issue?  Also, overall are these IR numbers ok for new batteries?   Thanks.
   

   

20's is quite high for brand new pack. The whole pack is bad.
https://oscarliang.com/when-retire-lipo-battery/

its not as it should be on a quality cell, but i heard big gnb packs like 1300mah comes regular with a high internal resistance?? i believe i would give them a try anyway - not sure about, i dont own any big gnb battery

(28-May-2021, 05:16 AM)voodoo614 Wrote: 20's is quite high for brand new pack. The whole pack is bad.
https://oscarliang.com/when-retire-lipo-battery/

thanks for the response and link voodoo.  I'll take a look.

(28-May-2021, 12:22 PM)hugnosed_bat Wrote: its not as it should be on a quality cell, but i heard big gnb packs like 1300mah comes regular with a high internal resistance?? i believe i would give them a try anyway - not sure about, i dont own any big gnb battery

I'm going to try and see what the LHS can do/say about replacing it.

Assuming your charger's IR measuring is correct, it's very unusual to have such large difference in IR between cells. I wouldn't say it's bad bad, but it certainly won't perform as well as it should be.

I ordered 5 pcs of tattu 3S 550mah and almost all of them have IR of around 18-25 ohms.. I talked to the store and they told me it is usual for these smaller packs?

(01-Jun-2021, 08:26 PM)Oscar Wrote: Assuming your charger's IR measuring is correct, it's very unusual to have such large difference in IR between cells. I wouldn't say it's bad bad, but it certainly won't perform as well as it should be.

I reached out to the LHS and they used an IR tool and measured low.  I ended up ordering a new charger and will measure it again to see the differences with my current charger.

Thanks for the input Oscar.

I just got 2 new 6s 1350mah packs and they also have fairly high IR for a new pack, measured off a HOTA D6 Duo. Lowest is 8ohm and highest 20ohm. I should also say that I just checked all my batteries that were in storage for the last 8 months and 2 of my 6s batteries had cells 1 & 2 dead (well, not dead but at 1v and not holding charge). They weren't even a year old and not that many flights. So, I'm not feeling that hopeful about GNB quality.

(11-Jun-2021, 02:23 PM)AlanB1976 Wrote: I just got 2 new 6s 1350mah packs and they also have fairly high IR for a new pack, measured off a HOTA D6 Duo. Lowest is 8ohm and highest 20ohm. I should also say that I just checked all my batteries that were in storage for the last 8 months and 2 of my 6s batteries had cells 1 & 2 dead (well, not dead but at 1v and not holding charge). They weren't even a year old and not that many flights. So, I'm not feeling that hopeful about GNB quality.

Thanks for your input Alan.  I'm still waiting for the IR tool to arrive.  Should be sometime next week and I'll be able to get a better reading.

A quick update.  IR tool finally arrived.  Tested the 2 lipos and they're showing much better than my initial post.


Batt1
   

Batt2
   

What IR tool did you get? And how much?

It looks like a LiPo ESR Meter Mark II ($150)...

https://www.progressiverc.com/products/l...er-mark-ii

(17-Jun-2021, 09:47 PM)SnowLeopardFPV Wrote: It looks like a LiPo ESR Meter Mark II ($150)...

https://www.progressiverc.com/products/l...er-mark-ii

Correct, this model.

seems pretty usless the ir mesurments of that charger.
i would like to see a testing review about internal resistance mesurement on various chargers :-)