Test/review of VBatty 32700 3.2V 7000mAh (Grey)

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HKJ
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Test/review of VBatty 32700 3.2V 7000mAh (Grey)

VBatty 32700 3.2V 7000mAh (Grey)
DSC_4585
Official specifications:


  • Voltage: 3.2V (limit voltage:2.0-3.65V)
  • Capacity: Max 7000mah
  • Cycle times: about 2000 times
  • Size: 32*70mm
  • Max discharge current: 5C
  • Discharge current: 3C

VBatty%2032700%203.2V%207000mAh%20(Grey)-info
This is a large LiFePO4 cell.
DSC_4584
DSC_4586 DSC_4587
DSC_4588
The cell do not have any markings on it.
VBatty%2032700%203.2V%207000mAh%20(Grey)-Capacity
The 7000mAh s a bit optimistic, but it is definitely 6000mA and discharge current do not really matter. The cells do not matches perfectly.
VBatty%2032700%203.2V%207000mAh%20(Grey)-Temp-20.0
VBatty%2032700%203.2V%207000mAh%20(Grey)-Temp-30.0
VBatty%2032700%203.2V%207000mAh%20(Grey)-CapacityTimeHours
VBatty%2032700%203.2V%207000mAh%20(Grey)-CapacityTime
VBatty%2032700%203.2V%207000mAh%20(Grey)-Energy
VBatty%2032700%203.2V%207000mAh%20(Grey)-PowerLoadTime
VBatty%2032700%203.2V%207000mAh%20(Grey)-TripCurrent
VBatty%2032700%203.2V%207000mAh%20(Grey)-Charge
Conclusion
As usual with LiFePO4 the output voltage is fairly stable during discharge and with 6000mAh there is a fair capacity in the battery and this is also the case at 30A.
Notes and links
The batteries was supplied by batteridoktorn.se for review.
How is the test done and how to read the charts
How is a protected LiIon battery constructed
More about button top and flat top batteries
Graphical comparison to 18650 and other batteries
Graphical comparison to 26650 and other batteries

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

Barkuti
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Impressive combination of energy density and discharge performance in this class without a doubt. Quite good consistency too. 

When you add up the price of these cells, in my honest opinion the result can only be qualified as outstanding.

 

BlueSwordM
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Yes, 135Wh/kg is excellent for LifePO4.

It’s in fact top of the line.

My very own high current Beryllium Copper springs Gen 3:
http://budgetlightforum.com/node/67401
Liitokala Aliexpress Stores Battery Fraud: http://budgetlightforum.com/node/60547

HydrAxx
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BlueSwordM wrote:
Yes, 135Wh is excellent for LifePO4.

It’s in fact top of the line.


Yes, but I find that you quickly forget the 141 grams of net weight and 7000mAh exaggerated or imaginary (your choice), it is not so good weight/performance ratio, I find that the INR26650-55A from PLB has a much better weight/performance ratio, after that is just my personal opinion.

Can a single flapping of a butterfly's wings trigger a tornado at the other end of the world?

BlueSwordM
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Yeah of course.

Still, if it was rated for 6000mAh instead of 7000mAh, it would be very good for a LiFePO4 cell.

Regular lithium-ion 26650s do have much higher energy density densities(135Wh/kg vs 210Wh/kg).

My very own high current Beryllium Copper springs Gen 3:
http://budgetlightforum.com/node/67401
Liitokala Aliexpress Stores Battery Fraud: http://budgetlightforum.com/node/60547

Barkuti
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I do not care about specs or claims. I believe in actual unbiased tests. Considering that, this LiFePO4 cell is amazing. Each cell has its applications, yes the PLB INR26650-55A whatever is much more energy dense, Sanyo NCR18650GA, LG MJ1/M36 or Samsung 35E even more. What's the point?

If I were to choose a cell for an UPS or automotive application this one fits way better than li-ion. Or, for example, as a MagCharger battery swap (2S cells).

If you don't like dishonesty just be trustworthy no matter what. As I believe, it always ends up being beneficial.

In my language there's a proverb which says Las mentiras tienen las patas muy cortas, which literally translates into Lies have very short legs. I think the meaning can Wink be understood.

 

Cheers Party 

Barkuti
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By the way, I remember having requested Henrik this review long ago (post #619 in Review request for HKJ [Rechargeable Batteries]). Please take a look at the specifications which are found in the sale advertisement I linked:

 

These figures certainly look more trustworthy than any VariCore or VBatty claims. 

 

Party 

Hobbyfotograaf
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I am using 2 of these cells in a solar powered light to replace a lead-acid battery, and it works just fine.
(for about one month now, i hope they last longer than the lead-acid battery, that was only one year old and the capacity was only 150mAh instead of 4Ah)
The capacity test on my hobbycharger gave about 6500mAh, but my cheap hobbycharger is not professional measure equipment like HKJ is using.

To protect the cells for over voltage and under voltage i use this protection board: https://nl.aliexpress.com/item/2S-8A-Li-ion-7-4v-8-4V-18650-BMS-PCM-15A-Peak-current-battery/32800676048.html?spm=a2g0z.10010108.1000013.3.3e367ecfk06lou&pvid=fbbf3d65-a32c-4bf2-8991-8767aa669f45&gps-id=pcDetailBottomMoreThisSeller&scm=1007.13339.90158.0&scm-url=1007.13339.90158.0&scm_id=1007.13339.90158.0

BlueSwordM
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So, where did you get your cells?

I’d love to build a car starter with some of these cells.

Would be dope. Or maybe I should just be using LiFePO4 pouch cells instead for easier connections.

My very own high current Beryllium Copper springs Gen 3:
http://budgetlightforum.com/node/67401
Liitokala Aliexpress Stores Battery Fraud: http://budgetlightforum.com/node/60547

Agro
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I don’t have any 32650 light but I imagine the diameter would be very comfortable to hold. Energy density doesn’t match the top cells (unless you limit your search to only match the chemistry), neither volumetric nor gravimetric but 150W/cell pulse with 90W/cell continuos is quite good. Would be a nice choice for some hot rod. Smile

Barkuti
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Given the discharge curves of this cell, it would require a buck/boost driver for proper emitter handling when 1S/1S cells/emitters.

 

Party 

Agro
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Or 3s cell / 2s LED…High Vf LED. Nice 4.2V at 30A. Smile

Barkuti
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Driver development needs to step up further. If you keep thinking in plain MOSFET switches controlled with ATtiny microcontrollers this is unlikely to happen. Regulation is good, full regulation even better. Keep improving it. 

 

Party 

Agro
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I love regulation! I love FET based linear drivers for their low cost and high power density. I love induction based drivers for their efficiency.
But boosting at 50A input is expensive.
And a 32700 light won’t be superb in lm*h/g or lm*h/mm³. Therefore here I value efficiency less than elsewhere.
But I view these cells as a good match for big toilet plungers. Cheap, probably better grip than N*26650 and 4N*18650, powerful.

Hobbyfotograaf
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BlueSwordM wrote:
So, where did you get your cells?


https://nl.aliexpress.com/item/32650-3-2-v-7000-mah-lifepo4-oplaadbare-b...
led4power
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Rusty bottom means they are probably factory rejects.

Hobbyfotograaf
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led4power wrote:

Rusty bottom means they are probably factory rejects.


The cells i got did not have rust, they were clean.
Barkuti
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Rust in cells can form in humid saline environments, near cold shores for example. A friend of me took a few cells in a trip to the northern lands of Spain and they came home with some serious rust crust, particularly in the more frequently used units. We were cleaning and rewrapping them the other day.

On the other hand a bit of rust is probably no issue for chinese factory quality control departments, and certainly not for their wholesalers/storekeepers. And given my knowledge in this regard, neither is for me. 

 

1stein
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Barkuti wrote:


In my language there’s a proverb which says Las mentiras tienen las patas muy cortas, which literally translates into Lies have very short legs. I think the meaning can Wink be understood.


 


Cheers Party 

Kłamstwo ma krótkie nogi. In polish this proverb translates exactly the same. More common than I thought.

walrus
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I’m surprised that there’s not much discussion about these cheap cells. I have ordered many batches from Aliexpress and Ebay from different manufacturers. I have not tested all of them yet, but here’s some initial results:

  • Noname cells from Ebay: average capacity about 5800mAh
  • Varicore brand cells from Aliexpress: average capacity about 5850mAh
  • Liitokala brand cells from Aliexpress: only one tested so far. Capacity 6262mAh

All cells look pretty much the same, but Liitokala has slightly different looking positive pole. Capacity was tested by discharging to 2V using ZB2L3 module with 2 Ohm resistor.

For the price these cells perform great and have pretty consistent capacity. Liitokala might have little more capacity than others, but they cost slightly more. I’m really happy if these really last the 2000 cycles mentioned in the description.

Does anyone else have experience or measurements about these gray 32700 LiFePo4 cells?

Jerommel
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Let me just bump this thread.

I want to buy 4 of these cells, but i would like to know who sells the best ones, or the best value for the price.
Many many AliExpress stores sell them, but even though they all have a gray wrapper, there are different specifications, prizes and even sizes (between 32600 and 32700).
Soooo…. Any advice is welcome.

(i want to use them in a MAGLITE 3D)

2Q19

Barkuti
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Jerommel, I usually keep track of stuff like this so, according to what I have, the shop where Henrik got the cells for his review (#1874160 LiitokalaVariCoreFlagshipStore) is where you should look at, section 32700

Jerommel
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Okay, thanks Barkuti. Beer

2Q19

Jerommel
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Hmmm… I’m still not sure, saw some discouraging reviews there, but these big cells are not popular here, so i’ll probably have to try my luck..

But if anyone else has a good suggestion for where to buy 4 of these, let us know.

2Q19

Barkuti
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Jerommel wrote:
Hmmm... I'm still not sure, saw some discouraging reviews there, …

And what is the value of a review written by someone who doesn't knows where his/her arse is? You know what this means, doesn't it?

The cells are good. Their consistency could be better, I know. But with LiFePO4 this is less important, at least with regards to battery pack assembly as I've already discovered the chemistry is self-balancing.

If you do care much about using them in series, buy twice or thrice the number of cells you need and, with the help of some battery capacity measuring device, sort/bin them low to high and make balanced packs. I recently bought this inexpensive EBD-M05 constant current capacity tester, discharges at up to 5A with 4-wire independent voltage monitoring and does discharge graphs. User HenrysCat has one, check: