LifePO4 750Mah 3v battery question

[panderson01]

I just received 2 sets of batteries today from VK, charged 'em up, dropped them in my V3 and no fire? Took 'em out, checked 'em, good!

Did the same with the second set, no fire but checked out good!

Put my old bats in, fired right up?

"Mmmm?", I say to myself.

I looked at 'em, they (at first) looked the same, but I found that the positive nipple on the new ones I just received are shorter, "damn!", I say to myself.

I know this is not a VK issue, but has anyone else run across this?

 

[SSRob]

What device are you using them in?

 

[panderson01]

What device are you using them in?

Puresmoker, Prodigy V3

They work fine in my Xhaler though, which is my backup device.

I figured I would have to find another flat washer for my V3 to make up the difference.

 

[SSRob]

That's wierd because I believe the Tenergy LiFePo4's are what comes with the V3 kit.

 

[cypresss]

Can you hear the batts sliding around if you shake the V3? Just wondering if it is a tight fit. Maybe because of the atty you're using on of the batteries is over-discharging and the protection circuit is tripping?

 

[panderson01]

That's wierd because I believe the Tenergy LiFePo4's are what comes with the V3 kit.

Yeh, when I ordered the V3, I got one set, and I ordered some more from somewhere else, I forget where, but it looks as if Tenergy made a change somewhere along the line.

Sorry for the bad pic, but here are the 2 side by side.

 

[SSRob]

cypress, the LiFePo4 batteries don't have a protection circuit because they aren't as volatile as li-ion technology.

pander, I do see the difference but I am surprised this is causing the V3 to not work. Is there a spring in the V3 that you can stretch out a tad to compensate?

Thanks
Rob

 

[panderson01]

pander, I do see the difference but I am surprised this is causing the V3 to not work. Is there a spring in the V3 that you can stretch out a tad to compensate?

Thanks
Rob

Rob, the function of the spring is to keep the battery off of the button until pressed, it's not used as the negative contact in the unit.

The issue is the dimension from the inside atty connection to the button screw. When the button is pressed all the way, the distance between the screw and the inside atty connection is greater than the 2 new batteries, therefor not making contact.

Tomorrow I will pick up a small flat washer to try and make up for that difference and hope that my fix will still allow me to use the older batteries as well and I'll post the results, as I'm sure someone else will have the same issue.

Paul

 

[SSRob]

From what I've been told, the washers are provided just for this purpose since there is some variation between lengths of the 17670's and 2 x 123's.

Thanks
Rob

 

[panderson01]

I just picked up a pack of M8 stainless flat washers and put it on top of the other and it worked fine. It does reduce the throw with the older batteries, but still works fine, mission accomplished.