IMR Batteries

[Parellax]

I have been using six 14500 IMR batteries since I started my quest for 4K. At first I was worried about the fully charged voltage, but I haven't damaged a board yet so I am comfortable using them. The red Efest 700 mAh version is no longer being made so I tried the MXJO brand. They get stuck because the positive ends are too wide. So then I got in touch with Efest to see if they had an alternative. I received two sample sets today that are being manufactured now. Both slide right in, and out. They did however send me flat tops which made the stacks a little too short. I have seen 800 mAh version for sale in button top. The other is a 650 mAh battery. I bent the battery tabs on the door out, and both sets power up the gun now. All I need to do now is test them on the range.

[Parellax]

I just tested both sets of Efest IMR's. Both of them work with 4K.

[Parellax]

More testing over the weekend revealed the 800 mAh batteries are only good for 30 to 50 rnd bursts at 4K. They are only rated for 2.2 A output. I'm actually surprised they work at all. I will be testing the 650 mAh batteries more thoroughly, but they have a much higher C rating (well above what it takes to run the bird) so I am not anticipating problems.

[DU-BB]

More testing over the weekend revealed the 800 mAh batteries are only good for 30 to 50 rnd bursts at 4K. They are only rated for 2.2 A output. I'm actually surprised they work at all. I will be testing the 650 mAh batteries more thoroughly, but they have a much higher C rating (well above what it takes to run the bird) so I am not anticipating problems.

They might have a higher C rating, but they have a lower capacity, so that will even itself out. I assume you read my sticky on battery types? I think I'll update that with a rundown on C rating, and capacity.

[Parellax]

Yes. You are the reason I stay up till 4a talking to Chinese battery manufacturers most mornings. Thank you? I always ask for the two amp ratings because C ratings don't do me any good. BTW. I helped changed the continuous output rating of the Efest 800 mAh batteries. I doubled it by having their engineers take another look. The new rating is 4.5 A. That's plenty for the SB-2K, but falls just short of what I have been working on.

[DU-BB]

I'm not running at 4k, but I'll stick with the 18650's in the buttstock, they work. That drill pack mod will do the job, too, I bet. For what it's worth, I tried running protected cells, with 3.5A cutoffs, and it would not even power up, it seems it takes a surge to start it that is more than 3.5A, so you need at least 4A, I should think.

[Parellax]

Thanks for the insight. Good to hear from you.