Preface

I have in for review a couple of 20700 cells. I asked for these because I expect that in the near future, more flashlights will begin to accept this size, and I want to be prepared! Also I just like testing cells. This is the Imren 3200mAh 25A/40A Flat Top 20700 Cell.

As always, click for bigger images!!!

Size: 20700

Type: IMR/Li-Mn (Rechargeable)

Rated Capacity: 3200mAh

Max Pulse Discharge Current Rating: 40A

Continuous Max Discharge Current: 25A

Approximate Size: 20.4mm diameter by 70.3mm length

Nominal Voltage: 3.7V

Protected: No

Style: Flat Top

Weight: 61.4g

Color: Gold/Red wrapper

Price

You can buy the Imren 3200mah 20700 25A/40A flat top battery at LiionWholesale, for $9.99.

Short Review

I can’t even test up to the full capabilities of these cells, but what I could test, these cells do well. They seem to be very good cells (I’ll support that statement by saying the cells didn’t get over 60 degrees C during the 20A test.)

Long Review

Package

Two of these cells ship in a card board Imren box.

Inside that box is the typical plastic flip-open box, suited perfectly to the 20700 size.

Build Quality

There’s a scratch-off authenticity sticker. I tried this, but the URL referenced on the sticker didn’t load for me.

I wouldn’t put much merit in the 40A pulse discharge claim. The 25A claim, however, is likely accurate (I tested up to 20A.)

Nothing much else to say about these. They’re very well wrapped, and the wrapper is very nice.

It’s a flat top cell, of course.

Size

These are 20.4mm diameter by 70.3mm length.

Bigger than an unprotected 18650 of course. Not all that much bigger than a protected 18650. There are possibly some lights in which this cell would fit already.

Testing

I’ve tried to keep the scales similar, so over time the charts will be generally comparable.

Discharge tests

Even discharging this cell at 20A, the temperature never got over around 60°C. Many (most?) cells are rated to 80°C, so this cell still had headroom.

Capacity

Rated at 3200mAh, and confirmed via the 0.2A discharge curve. The “B” cell reported 3269mAh, in fact, and I only take the cells down to 2.8V.

Energy

Bounce

This is a new section, and I added it just because I think it’s interesting. “Bounce back” is what the cell voltage does when the cell rests after a discharge. Interestingly, after heavy discharge rates, the cell bounces back higher. This corresponds to a discharge amount of less energy, and does mean that there’s energy left in the cell. So if I selected the cell with the highest bounce back (that’s the 20A B cell), and discharged it to 2.8V at 0.2A, I’d still find that there was a lot of energy still in the cell.

Charge test

Power, Constant

Since this is a 25A rated cell, I added a constant 20W curve.

Internal Resistance

Conclusion

This is a great cell for what flashlights are to come. Or, if you do other high-drain activities like vaping, then this cell is a good choice.

Buy these cells for $9.99 here at liionwholesale.com!

Up Next

I will post my review of the Sofirn Q8 tomorrow!

Notes

These cells were provided by liionwholesale.com for review. I was not paid to write this review.

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