Battery Pairing: how strict?

[smokin909]

Hi all,
I have two new Samsung 25r batteries I bought about a month ago.
I was going to use the pair on rotation for my IPV D2, so thinking I'd never need to pair them, I used them twice down to 3.7v, separately, on a mech mod and recharged them twice. In the meantime I have decided to get a dual 18650 regulated mod (sigelei 150w) and the IPV D2 is nowhere in sight (yet) so the question is:

Can I still marry the two to the sigelei, having used them and charged them twice, or is it a no go?

 

[Baditude]

Having used them both just two times, I'd consider them to be new batteries.

 

[smokin909]

Thank you Baditude for that - I was hoping that might be the case but I just wanted to be sure.
I'm not sure when the D2 will ready for shipping (FT preorder), but the Sigelei is ready to go, so I figured I could use the 25rs until I actually received the D2 (who knows when!) then I'll get a couple of VCT5s and marry them right away to the Sigelei and swap the Samsungs over to the D2.
Or I might love my Sig so much I'll cancel the D2 all together and keep using my mech 18350s and Tesla 2 sub box as my stealthy runarounds.

 

[Baditude]

There is strong evidence that the vtc5 is only a 20 amp cdr. The vtc4 is a true 30 amp cdr battery.

 

[Mooch]

Hi all,
I have two new Samsung 25r batteries I bought about a month ago.
I was going to use the pair on rotation for my IPV D2, so thinking I'd never need to pair them, I used them twice down to 3.7v, separately, on a mech mod and recharged them twice. In the meantime I have decided to get a dual 18650 regulated mod (Sigelei 150w) and the IPV D2 is nowhere in sight (yet) so the question is:

Can I still marry the two to the Sigelei, having used them and charged them twice, or is it a no go?

I agree with @Baditude...no problem pairing them up.

 

[smokin909]

There is strong evidence that the vtc5 is only a 20 amp cdr. The vtc4 is a true 30 amp cdr battery.

Yes I had read this - why is it that everyone is listing them as 30A CDR? Reputable vendors and even the guy I get my batteries from state it. The vendor I buy from when I'm here buys his AW IMRs direct from Mr AW, he does mAh batch tests his VCT4 and 5s to ensure that they are indeed 4s or 5s and buys direct from the source, not using reclaimed laptop batteries and he states them as 30A CDR as well. I'll message him and find out more - otherwise I'll stick with the VCT4s so that I'm on the safe side.

 

[Baditude]

Yes I had read this - why is it that everyone is listing them as 30A CDR? Reputable vendors and even the guy I get my batteries from state it. The vendor I buy from when I'm here buys his AW IMRs direct from Mr AW, he does mAh batch tests his VCT4 and 5s to ensure that they are indeed 4s or 5s and buys direct from the source, not using reclaimed laptop batteries and he states them as 30A CDR as well. I'll message him and find out more - otherwise I'll stick with the VCT4s so that I'mon the safe side.

Mooch has been doing independant bench testing, look for the link to his blogs in his signiture.

 

[smokin909]

Mooch has been doing independant bench testing, look for the link to his blogs in his signiture.

Thanks - will do.

EDIT: I just realised who Mooch was. I bought the Samsungs for my D2 based on his testing results

 

[Mooch]

Yes I had read this - why is it that everyone is listing them as 30A CDR? Reputable vendors and even the guy I get my batteries from state it. The vendor I buy from when I'm here buys his AW IMRs direct from Mr AW, he does mAh batch tests his VCT4 and 5s to ensure that they are indeed 4s or 5s and buys direct from the source, not using reclaimed laptop batteries and he states them as 30A CDR as well. I'll message him and find out more - otherwise I'll stick with the VCT4s so that I'm on the safe side.

Most vendors don't have the time to test their batteries. If most people say the VTC5 is 30A then that's what they'll sell it as. The tech info document for that battery though only shows discharge graphs up to 20A, at temperatures high enough to indicate that's as far as the battery should be taken.

How did it get rated at 30A? Perhaps early testers/reviewers didn't measure temperature (very few do) and just saw they could discharge it at 30A and rated it at that? They would have to ignore the huge voltage drop too, but I've seen that happen before. Or, they only did pulse testing and that rating became popular and spread?

 

[smokin909]

Thats interesting how results taken out of context spread and become a specific fact. Thankfully we have people such as yourself who are willing to put these claims to the test - then it's up to each of us to make a choice with all the available information.

In the meantime, I'll just stick to building within the 20A limit of the battery - fancy that!

 

[sonicbomb]

Most vapers can do little more than trust the number printed on the side of the cell. Purple Efest base their entire business model on this, that and a colorful wrapper.

 

[Baditude]

Most vapers can do little more than trust the number printed on the side of the cell. Purple Efest base their entire business model on this, that and a colorful wrapper.

For the uninformed who are reading this comment for the first time:

Purple Efest Batteries: Not As Advertised

 

[evan le'garde]

There is strong evidence that the vtc5 is only a 20 amp cdr. The vtc4 is a true 30 amp cdr battery.

Now i'm confused !. On Mooch's table it says that VTC4's are only 20 amp cdr based on his tests.

 

[d4gger]

Mooch sets the CDR at 20A because at 25A and 30A (constant current, not pulsed) the cell gets hot enough to cause slight damage. He mentions on the cell's page that it can be pushed to 30A, but this will result in decreased cycle life.