IR advice, should I retire these? Dynamite Reaction 2S lipos for Losi Mini cars

[DavidB1126]

Well. Idk if I'm going crazy or if my charger is acting whacky. Both are at storage voltage (3.8 per cell) I'll do another test. I haven't ran these batteries in more than 4 months. I had both on storage charge for that time. Any advice? No signs of swell or puffing. @Greywolf74 and others, any advice?

 

[Slick2500]

That second one for sure that is just insane. But for shits and giggles plug the batteries balance lead directly into the charger and eliminate the balance board.

 

[DavidB1126]

That second one for sure that is just insane. But for shits and giggles plug the batteries balance lead directly into the charger and eliminate the balance board.

Here is directly into the charger.
600mah battery: 48.3 for both cells. Poor picture quality.

 

[Slick2500]

View attachment 158910View attachment 158911
Here is directly into the charger.

Okay just wanted to eliminate the balance board as a possible culprit as they can be kinda flakey sometimes. The pack at 50 is probably done, the other one might be okay as my 350mah Dynamite 2s is at 17.

 

[DavidB1126]

Should.i use the discharge on the charger or do what my uncle said? He said put the lipos in a bucket of salt water. I guess that the salt with discharge the lipo to 0?.

 

[Slick2500]

Should.i use the discharge on the charger or do what my uncle said? He said put the lipos in a bucket of salt water. I guess that the salt with discharge the lipo to 0?.

All salt water does is corrode the battery terminals. Connect it to a 12v automotive lightbulb, put it outside and away from anything flammable.

 

[tntpoof]

a bulb with your connector of choice .if you solder both elements together its a 10 amp discharge

 

[DavidB1126]

Posted in one of my mini b FB groups. One guy has seen more (82 mΩ per cell) another guy said that these batteries IRs are always sit high.

 

[Greywolf74]

Those are probably fine. Small lipos have higher IRs naturally than the bigger 5000mAh+ lipos we use. I just tested a brand new Reaction 650mAh after its first charge and it has roughly 27mOhm IRs. At storage charge the lightly used ones I have are around 45mOhm and the one I have the most use on which still works perfectly fine has approx 51mOhm IRs. I can charge them tomorrow and check them if youd like me too but I dont have time tonight. After being charged they will be lower but I'm honestly not sure how much lower as I dont generally use packs this small very often.

 

[Slick2500]

Those are probably fine. Small lipos have higher IRs naturally than the bigger 5000mAh+ lipos we use. I just tested a brand new Reaction 650mAh after its first charge and it has roughly 27mOhm IRs. At storage charge the lightly used ones I have are around 45mOhm at the one I have the most use on which still works perfectly fine has approx 51mOhm IRs. I can charge them tomorrow and check them if youd like me too but I dont have time tonight. After being charged they will be lower but I'm honestly not sure how much lower as I dont generally use packs this small very often.

I remember reading that the smaller lipos have a higher IR but I never thought they would be that high.

 

[DavidB1126]

One guy commented on my FB post and shared his readings. I think it was a 3s (don't know what mah) but in one cell he had 180 mΩ. And in another he had almost 200 mΩ
This is what the guy had.

Charging batteries and so far they are fine. They are not getting hot. Usually charge these batteries at 2 amps. I know I should do 0.7 or 0.8 but the batteries are fine.

 

[DavidB1126]

Here are the IRs after balance charging

 

[cdstatz]

Here's what I have with a brand new Reaction 2 650mah out of my new mini b.

 

[DavidB1126]

Ok. Looks like I'm fine. I was just concerned because the bigger packs for my 1/10 bashers are usually any where between 1.0 to 20 mΩ. Didn't know that smaller packs tends to have an higher IR.

 

[Greywolf74]

One guy commented on my FB post and shared his readings. I think it was a 3s (don't know what mah) but in one cell he had 180 mΩ. And in another he had almost 200 mΩ
This is what the guy had. View attachment 158929

The thing that concerns me on this guys pack is the IR gap between the cells. Thats much more of a concern than just having high IRs.

 

[Bogda89]

For bashing I would not be concerned about it, just run them until they start puffing or don't hold charge