Boston-Power Swing 5300 Li-ion cell test


100 W
Oct 8, 2017
Original article:

Boston-Power is a US based manufacturer of Li-ion cells which makes them in China and Taiwan and supplies to HP, ASUS and EV makers.

The cell was bought from Queen Battery, a Chinese supplier of genuine batteries, who specializes mainly on EV and eBike market. Queen Battery has a branch in Europe which works with european customers like me:)

The Boston-Power Swing 5300 is a 3.65V Li-ion cell with a wide working temperature range (-40 to +70°C).


Specs taken out of it's datasheet:

Nominal capacity: 5300mAh (at 0.2C discharge)
Nominal energy: 19.3Wh (at 0.2C discharge)
Nominal cell impedance: 16 mΩ
Life cycle at 100% DOD: >1000 cycles (at 1C discharge)
Discharge cut-off voltage: 2.75V
Max continuous discharge rate: 13A
Standard charging current: 3.7A, cut-off at 0.05A
Max continuous charge rate: 10.6A
Weight: 93g
Charging temperature: -20 to +60°C
Discharging temperature: -40 to +70°C
Dimensions: 37.2 x 64.8 x 19.1mm

I've tested with ZKETECH EBC-A20 and a self-made battery holder. It's a PC-connected battery tester supporting 4-wire measuring and discharging at up to 20A.

I've tried to follow all the prescriptions of the IEC61960-2003 standard concerning battery's capacity measurement. Before each discharging cycle the battery was charged at 3.7A to 4.2V (cut-off at 0.1A, which is higher than 0.05A allowed by the manufacturer, but it's the lowest supported by EBC-A20). Before each discharging or charging i've held a 1-1.5hrs pause. The environment temperature was 21-23°C.

Discharge cut-off voltage was 2.75V in all cases. I've done a 0.2C (1.06A) discharging to check the nominal capacity, then I've discharged at 5.0 and 10.0A and finished with the max allowed continuous discharge current - 13A.

The results i've grouped together, so it must be easier to compare them.

As turned out, the battery is not overrated and at 0.2C it gives out 5318mAh - a lil bit more than the nominal capacity. The amount of energy is also slightly higher than the nominal - 19.36 vs 19.3Wh.

At 5.0A the capacity is lower than at 10.0A, but the amount of energy is higher. This is a normal thing, and the important one is the amount of energy.

At 13.0A the measured capacity was 5091mAh and the energy - 16.48Wh.

The results are good and not surprising for me. This is a high quality cell which can give out almost 5100mAh/16.5Wh at 13.0A. In some cases the prismatic form is preferable than cylindrical and i think it will help to build battery packs with higher energy density than in case of using 26650 cells with ~5000mAh capacity.

Check out my YouTube channel for batteries, chargers and other stuff reviews.
In my blog where you can find all my reviews in one place. Every new test/review is first published on YouTube and in the blog.
Thank you always looking for the next great battery. Plus I like the 4 wire battery tester. Now the question how much are these cells ? Welcome to E.S.
999zip999 said:
Thank you always looking for the next great battery. Welcome to E.S.
Thanks for warm welcome!:)
999zip999 said:
Now the question how much are these cells ?
Queen Battery sells them at US$ 2.6 plus shipping or US$ 5.3 (100pcs/lot) or US$ 5.7 (30pcs/lot) with free shipping to USA/Europe (UPS, FedEx, etc...), but it's possible to have a personal discount depending on the quantity/total price of your order. They are very customer-friendly:) They helped me to avoid european import taxes by sending the batteries from their EU branch.
Hillhater said:
It still looks suspicously like a pair of 18650s assembled in parallel ?
Pull the shrinkwrap off and let us see what is inside . :wink:
According to your own posts and the image you linked in this thread from a few months ago:
they're not. ;)

There's also an older thread
that actually has a pic of one cut open
Yes , i have seen similiar "unrapped" pictures before, but even there it still looks "suspiciously like". A pair of 18650s in a metal case.!
But AW linked to a post with the can cut open to prove it is a single , oval wound, cell construction.
Its basic performance specs are not outstanding by current standards, but maybe it has some advantage in cycle life, safety, US availability, etc ?????
It seems that they have outstanding temperature operation range. Maybe the best on the market of cells with C(Si) anode. At least according to the datasheet.
cheapcookie said:
It has incredible belgian chocolate in it ... :wink:
And Belgian beer as electrolyte :)

Pajda said:
It seems that they have outstanding temperature operation range
And incredible life cycle, even at 100%DOD
I have some of these laying around in an old medical device pack. It's got like 12 of these inside.

The cycle life claims are most intriguing, but are the claims true? Cycling these 1000 times or so sure would take a while.

Also I like the holders that are available for these cells. Could make for some pretty well put together packs!
redilast said:
I have some of these laying around in an old medical device pack.
Could you give more info about that medical device please?
What's the recommended way to connect the cells? Can you just spot weld the ends using .15mm nickel?
Thanks for sharing your test results.
Nice to see they have 2 flat sides ! Makes the pack more energy dense per unit volume and also easier to liquid cool !

Also the vent notch on side is a cool safety feature, at least the sidewall failure location is predictable. But the inside visible in this post :

OMG that looks so messy ! The inside of a cylindrical cell inspires much more confidence with no kink zone whatsoever and perfectly wrapped material... Would be curious to see how a big batch of this cell survives abuse
shinyballs said:
What's the recommended way to connect the cells? Can you just spot weld the ends using .15mm nickel?
No idea. hemo says they are hard to weld.
The cells are hard to tab weld and the ends are as hard as nails apparently. They were conceived to work with a modular set up/connection, which I believe in themselves are not cheap to buy.
Jimmy the boss at Insat Intl/ BGA Reworking in North London has boxes and boxes of these in his work space, and tab welds using copper. His normal industrial spot welder couldn't manage decent welds to the Boston's, so in order to accomplish this he said his new state of the art welder cost about 30k sterling.
Might be interesting to see if any one buys these and whether they are able to manage welding them or not.
Excellent review here on this battery. Has anyone since tried welding any of these? I corresponded with the gent who did that review on Youtube and was told problem soldering them just like 18650s I would think they could be spot welded just as easily.
Yes they could be easily spot welded by cheap Chinese welders as for example LG HG2 cells.

.. edited for writing nosenses :oops:
You are right that 18650 cells are in steel cese. I found one datasheet for Boston Swing 5300 with info that their casing is made from aluminium. But I did not checked that. Anyway I have no problem with welding nickel tabs on Swing 5300 with the same setting as on 18650 cells.