Do you LiFePO₄? Some interesting cells from Heter Battery

[Barkuti]

A few months ago I inquired Henrik whether he could review a couple 18650 LiFePO₄ cells from Heter Battery sold under ENERpower brand at NKON:

• HTCFR18650-1100mAh-3.2V “33A”
• HTCFR18650-1800mAh-3.2V “3C”, check out the review @ lygte-info.dk:

Wellp, given the excellent result attained by the high capacity cell (did not even reached ≈60°C at 10A continuous), I have little reason to disbelieve in the high discharge cell figures. I guess one could run a mech with two of those cells at up to ≈150W, maybe a little bit more, safely. Nonetheless better wait for the review(s).

Cheers

 

[Rossum]

The trouble with LiFePO₄ remains what it always has: Noticeably lower capacity in watt-hours than traditional li-ion.

Is that a good trade-off for the much safer chemistry that LiFePO₄ provides?

 

[Barkuti]

Well, I'd prefer to avoid safety debates. Good sense, wisdom and technical know-how are my bets in safety regards.
Given the quite affordable unit price of these cells it is possible to grab many pieces and so you have enough “rounds” to vape. I guess this may be not for those used to automatic transmission vehicles, though.
The very flat discharge curve of LiFePO₄ cells means they're very well suited for unregulated mods.

 

[dripster]

The trouble with LiFePO₄ remains what it always has: Noticeably lower capacity in watt-hours than traditional li-ion.

Is that a good trade-off for the much safer chemistry that LiFePO₄ provides?

Mech users typically don't use the full capacity of their traditional round cells, as the vape usually has become too weak by the time the resting voltage of the cell has gone down to, say, around the 3.7V-3.65V range. The main obstacles with LFP have been 1/ lacking widespread availability of the good performing ones, 2/ the clunkiness of using two A123 Systems ANR26650M1-B cells in series when there were no available smaller size LFP alternative choices offering good performance. To a lesser extent, faster aging of LFP compared to traditional round cells might also part explain why LFP in vaping on the mech never really took off, as mech users are already a minority it would seem. I'm still contemplating on whether I should finally get the A123 from NKON for my Vapergate The 99. I might just order the Enerpower along with it, for all my HOGs and for my quad-18650 stacked tube mech.

 

[Barkuti]

Heter/Enerpower 18650 3.2V 1100mAh (Blue) review @ lygte-info.dk
Summing up:

Cell delivers rated capacity 100% issue free.

Super nice consistency. Full capacity delivered at 30A discharge rate.

At 30A discharge rate hottest cell ended up at Δ+27°C and reached Δ+37°C absolute maximum (temperature variation values).

Looks like a pretty good cell in my book, but let's wait to see if Mooch has something to say.

Cheers

 

[Robin Becker]

I found for you the website with all the technical specifications to down load:
LiFePo4 Batteries | ENERpower

Btw...Mooch already tested the 26650 with 2300 mAh here some time ago...

 

[Mooch]

Heter/Enerpower 18650 3.2V 1100mAh (Blue) review @ lygte-info.dk
Summing up:
Cell delivers rated capacity 100% issue free.
Super nice consistency. Full capacity delivered at 30A discharge rate.

At 30A discharge rate hottest cell ended up at +27°C and reached +37°C absolute maximum.

Looks like a pretty good cell in my book, but let's wait to see if Mooch has something to say.

Cheers

Umm...that chart shows the temperature increase, not cell temperature.

The cell shows obvious signs of stress starting at about 15A, with that early huge sag and then some voltage recovery due to cell heating lowering the internal resistance. Depending on your cutoff voltage you might only get a few mAh out of it at very high discharge current levels due to that sag.

With a capacity that low you’d get very, very little vaping time at high current levels. Three or four in parallel would add up to a decent amount of vaping time if the mod was a mech and the very low voltage wasn’t an issue.

 

[Barkuti]

Umm...that chart shows the temperature increase, not cell temperature.
…

Relative to absolute temperature just add ambient, i.e. for 25°C ambient cell temperature would end at 52°C/62°C when continuously discharged at 30A.

…
The cell shows obvious signs of stress starting at about 15A, with that early huge sag and then some voltage recovery due to cell heating lowering the internal resistance. Depending on your cutoff voltage you might only get a few mAh out of it at very high discharge current levels due to that sag.

With a capacity that low you’d get very, very little vaping time at high current levels. Three or four in parallel would add up to a decent amount of vaping time if the mod was a mech and the very low voltage wasn’t an issue.

I saw this coming.
Concerning the cut-off thing I do not see a problem, 2V is the usual LiFePO₄ cut-off, doesn't it?
Above 2.5V does it too because of the quite flat voltage/capacity curve, average looks to be at ≈2.6V. It could be interesting to see some pulse discharge curves.
Vapers with these cells are namely going to be experienced mech users. In my book I see a conscious fellow with a voltmeter equipped mechanical flute. No cut-off issue. That's all.
I would do it that way if I were to vape. But I've killed all my substance addictions, even alcohol.

Cheers

 

[Mooch]

Relative to absolute temperature just add ambient, i.e. for 25°C ambient cell temperature would end at 52°C/62°C when continuously discharged at 30A.

I saw this coming.
Concerning the cut-off thing I do not see a problem, 2V is the usual LiFePO₄ cut-off, doesn't it?
Above 2.5V does it too because of the quite flat voltage/capacity curve, average looks to be at ≈2.6V. It could be interesting to see some pulse discharge curves.
Vapers with these cells are namely going to be experienced mech users. In my book I see a conscious fellow with a voltmeter equipped mechanical flute. No cut-off issue. That's all.
I would do it that way if I were to vape. But I've killed all my substance addictions, even alcohol.

Cheers

That is what I was talking about. You said the cell reached 37°C maximum but it didn’t. It reached room temp plus 37°C...an important distinction we should always mention.

The rated cutoff for LFP cells is often 2.0V but that doesn't matter if the cutoff you want is above that. Most people like to stay above the rated cutoff to improve cycle life. Doing that can mean severely limited delivered capacity for an already very low capacity cell.

I agree. These cells are useless for regulated devices and are limited to series mech use. I think most would go to 26650’s though due to the very low energy density of LFP and low capacity of the 18650’s.

Just my observations and thoughts...

 

[Barkuti]

That is what I was talking about. You said the cell reached 37°C maximum but it didn’t. It reached room temp plus 37°C...an important distinction we should always mention.
…

Mmmph, not exactly. I said +27°C and +37°C.

…
The rated cutoff for LFP cells is often 2.0V but that doesn't matter if the cutoff you want is above that. Most people like to stay above the rated cutoff to improve cycle life. Doing that can mean severely limited delivered capacity for an already very low capacity cell.

I agree. These cells are useless for regulated devices and are limited to series mech use. I think most would go to 26650’s though due to the very low energy density of LFP and low capacity of the 18650’s.

Just my observations and thoughts...

I honestly do not know how much actual impact does cutting off low has in cell cycle life. I certainly know letting cells rest fully charged or close to is detrimental, but studies in this other regard are nowhere to be found besides those aimed at over discharging cells well below recommended cut-off voltages.
Anyway, some two or three cells in series mech could run reasonably well with this, in proper responsible hands of course. Despite the low energy density these cells are quite affordable, this means half a dozen or two won't break the bank while providing gameplay.
The flat discharge curve should please the “crowds”.

Cheers

 

[dripster]

Mmmph, not exactly. I said +27°C and +37°C.

When dealing with measured values in a written context, the plus sign should be used only to ensure unambiguousness will survive the potential flaws of written communication editing/transcript modern advanced technological procedures, as the reader might wrongfully assume a minus sign went missing if no plus sign has been specified. So, to avoid any confusion, +27°C is perfectly synonymous to 27°C, just like +37°C is also perfectly synonymous to 37°C, and, instead of just assuming we can guess what it is you must be talking about, that's why you need to specify that what you're talking about is the battery temperature minus the ambient temperature.

 

[Mooch]

Mmmph, not exactly. I said +27°C and +37°C.

In my line of work that just means 37°C above zero degrees-C. The plus sign is just there to reinforce the fact that it is not -37°C.

A delta from ambient would be indicated by something like “37°C above ambient” or “delta +37°C” or something similar.

While the engineering world often use degrees of change from ambient temperature the general public does not. An unambiguous temperature number is always preferable to prevent confusion. But, I do realize that you and I disagree on a great many things and that this will be one of them.

 

[Rossum]

Although I didn't have any problem deducing what @Barkuti 'meant, I agree it would have been more clear explicitly state that the number stated a "temperature rise" or something to that effect.

Then again, it's also not ideal when someone says, "This cell reached xx°C" without stating what the ambient/starting temperature was.

I wonder if some of this is due to the fact that we Americans are used to living and working in climate-controlled (air-conditioned!) spaces, where it's safe to assume a very tight range of starting temperature (rarely lower than 20°C or higher than 25°C) while that (particularly air conditioning) is much less common in Europe?

 

[Mooch]

Although I didn't have any problem deducing what @Barkuti 'meant, I agree it would have been more clear explicitly state that the number stated a "temperature rise" or something to that effect.

Then again, it's also not ideal when someone says, "This cell reached xx°C" without stating what the ambient/starting temperature was.

I wonder if some of this is due to the fact that we Americans are used to living and working in climate-controlled (air-conditioned!) spaces, where it's safe to assume a very tight range of starting temperature (rarely lower than 20°C or higher than 25°C) while that (particularly air conditioning) is much less common in Europe?

Or Asia? Could very well be!
A lot depends on the audience and context though. Something said to the general public might be done a lot differently than when said to a group of engineers.

 

[Barkuti]

Wellp edited my controversial post hope you like it better now.

Question for the experts by the way:

These are pictures of the low drain LiFePO₄ cell which comes from Heter Battery, I believe.

However:

The high drain cell doesn't looks like its sibling.

I wonder what could be the OEM manufacturing the high drain cell. Of course I understand it could also be Heter, but that is nowhere explicitly claimed.
Any thoughts/intuition?

Cheers

 

[Robin Becker]

Hi Barkuti,
if the batteries have the same UL-File they must come from the same manufacturer

 

[Barkuti]

Thanks for pointing out this UL thing, Robin Becker.
This definitively helps shed light into fake cell identification as cell can shape is generally peculiar and manufacturer characteristic.
Now I definitively know which OEM manufacturer produced that 4-pack of fake 25Rs I bought long ago while high LoL. Already relabeled and rewrapped 'em, I like to call things by their true name.

Cheers

 

[Mooch]

Wellp edited my controversial post hope you like it better now.

Question for the experts by the way:

These are pictures of the low drain LiFePO₄ cell which comes from Heter Battery, I believe.

However:


The high drain cell doesn't looks like its sibling.

I wonder what could be the OEM manufacturing the high drain cell. Of course I understand it could also be Heter, but that is nowhere explicitly claimed.
Any thoughts/intuition?

Cheers

It wasn’t an issue of not liking it before. I was merely making observations.

UL cell testing is fantastic but beware. Some companies just can copy valid UL numbers and put them on the wrap. Without knowing the true name of the company involved, for the genuine and suspect cells, we couldn’t know if the UL number was genuine for a particular cell.

There are definitely companies we can trust but for companies we don't know a lot about, or for a cell or wrap we haven’t seen before, we have to be careful about trusting a UL number.

The more cells that are tested though, the better. It will help with cross-referencing and detecting fakes.

 

[dom qp]

It wasn’t an issue of not liking it before. I was merely making observations.

UL cell testing is fantastic but beware. Some companies just can copy valid UL numbers and put them on the wrap. Without knowing the true name of the company involved, for the genuine and suspect cells, we couldn’t know if the UL number was genuine for a particular cell.

There are definitely companies we can trust but for companies we don't know a lot about, or for a cell or wrap we haven’t seen before, we have to be careful about trusting a UL number.

The more cells that are tested though, the better. It will help with cross-referencing and detecting fakes.

Hi Mooch. I like your hats. Do you like mine?

 

[Mooch]

Hi Barkuti,
if the batteries have the same UL-File they must come from the same manufacturer

Wish they differentiated between the different cells for each number. Too many chances for the less-than-honorable companies to fake things. But it’s still a great resource!