Anyone actually used the Boston Power 5300mAh cells?

I've seen a few samples tested, but no one actually using them, despite that they seem to be very competitively priced?

Maybe because they have too good parameters for the common people?

Pajda said:

Maybe because they have too good parameters for the common people?

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Sorry? Could you explain that?

I apologize for this inappropriate remark.

I'm trying to get an overview of all the currently available technologies of Li-Ion batteries on the market. But this manufacturer and the type of battery has long missed my attention. I had the prejudices that it was just another Chinese variation of the useless crap battery. But after about a month of intitial testing of Swing 5300mAh battery cells It seems that I could not be more wrong. Most of parameters listed in the datasheet are achievable and in most cases are even better in real life conditions. After first 50 cycles of my already completed cycle life tests it seems that the cycle life parameters from datasheet are also correct, which can make this cell one of the most robust cell of the market of small prismatic/cylindrical cells. Even LG HG2 (which is one of the best cells based on my test procedures) is outperformed in some parameters.

The only issue of this cell is that it belongs to High Energy category of cells, so it is good only for 2C continuous loads. But on the other hand it has higher nominal charging curent 0.7C (common is 0.5C) and initial 1C charge rate tests exhibits minimal wear.

Pajda said:

I apologize for this inappropriate remark.

I'm trying to get an overview of all the currently available technologies of Li-Ion batteries on the market. But this manufacturer and the type of battery has long missed my attention. I had the prejudices that it was just another Chinese variation of the useless crap battery. But after about a month of intitial testing of Swing 5300mAh battery cells It seems that I could not be more wrong. Most of parameters listed in the datasheet are achievable and in most cases are even better in real life conditions. After first 50 cycles of my already completed cycle life tests it seems that the cycle life parameters from datasheet are also correct, which can make this cell one of the most robust cell of the market of small prismatic/cylindrical cells. Even LG HG2 (which is one of the best cells based on my test procedures) is outperformed in some parameters.

Click to expand...

Okay, thanks for that.

I was beginning to dismiss them, and take their high Ah/$ as a sign they were being dumped; but then I came across this NASA pdf that shows they are being seriously considered for spaceflight use. It doesn't say they've been selected, but it has a few graphs pertaining directly to these cells, and some positive comments regarding the form factor and thermal performance.

Pajda said:

The only issue of this cell is that it belongs to High Energy category of cells, so it is good only for 2C continuous loads. But on the other hand it has higher nominal charging curent 0.7C (common is 0.5C) and initial 1C charge rate tests exhibits minimal wear.

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So 10.6A continuous rather than the 13A given in their specs?

If so, 3P would give approximately the same continuous draw capability as 4P 29E, but 50% more capacity for the same money.

Ah, I was looking into bad column, the continuous discharge rate is really 13A.

But I must say that I am not doing cycle life test (at least for now) with more than 1C discharge rate. When designing the HE battery for long life (more than 2 years with the goal of 10 years life) I'm using a "0.5 average" rule. That means average load(charge/discharge) up to 0.5C and 50 % depth of discharge. Almost all HE cells particularly in 18650 format are practically indestructible by cycling with 1C discharge rate up to 50% DoD but when you break this value the HE cells starts to loss their capacity very fast and so it is neccesary to use HP cells. You also need HP cells when there is demand for more than 0.5C average charge rate.

Previously, when i have considered the Boston Power cell, i have dismissed it on cost and availability grounds...
...IE, few vendors, and high cost/Wh.
Have the prices and availability improved now ?

I recently found price 4.28 USD with free shipping to US, EU for 100cells quote. That is 19.3Wh/4.28 USD = 220 USD/kWh. Not bad from my point of view 8)

Hillhater said:

Previously, when i have considered the Boston Power cell, i have dismissed it on cost and availability grounds...
...IE, few vendors, and high cost/Wh.
Have the prices and availability improved now ?

Click to expand...

I've only just started looking so I have no knowledge of history; and I'm in the UK where US sources cost a fortune in shipping, so I have to avoid them.

I have an email quote (Queen Batteries) for 30 for £112 ($152) shipped to the UK which comes out at 1492mAh/£.

The next best I've found is Panasonic UR18650ZY 2600mAh @ 1247.44mAh/£ (interEu) shipping extra, but they only have a spec'd discharge rate of 1.25A.
Next comes Samsung INR18650-29E 2900mAh @ 953.35mAh/£ (interEU) shipping extra. with a 8.25A continous spec.

I had a 15.9ah/39a 7s 3p Boston pack made for my Swizzbee but have found the 39a not enough and it sags like hell, originally I did ask the vendor for a 5p pack but he wasn't able to fit the quantity in the space I had available.
In the end I built a HE2 battery with Korean lipo Boss spot welder and parallel it with the Boston.
The 24v Heinzman brushed mid drive hub motor can draw over 60a so at least the sag is a lot better now.

If anyone here is still interested in these batteries ...I have posted in the online market as I have a large quantity of them.

Here's the link:

https://endless-sphere.com/forums/viewtopic.php?f=31&t=95471

Thanks, RH

I've heard rumors that Boston Power is already stopped production of those cells. Do you have any information about their availability in the future?

As far as I know they are readily available ....you can readily find them all over Alibaba, Ali Express etc. Of course it could be that they have a new battery ...as technology marches on but I am not aware of this. In the meantime ...the batteries are what they are stated to be and are new and I have a good supply of them presently ...and could get more if I wanted to. Hope this helps. RH

It's just 2 18650s put in parallel, is it not? I don't see the point.

No it is not, it is one wound cell in the 2x18650 proprietary format. There are two interesting parameters with this cell. First is the wide temperature operational range. I can confirm that this cell works very well even at -30°C, but this parameter is not so important for standard use.

The second interesting parameter was its price. About half year ago it was possible to get them for 3.5USD incuding shipping! But they become significantly more expensive in past few months and and thus lost much of their main advantage.

As Pajda said ...they are definitely not (2) 18650s in one pack. And I have had several buyers using these cells and very happy with them. And yes ....they have gotten more expensive so get' em while you can if you have an interest in them. And still available but they have now increased production in China itself as opposed to Taiwan. Same quality I am told but I have not tested any of the Chinese made yet.

Not mine, but a recent thread on a build that used them..


https://endless-sphere.com/forums/viewtopic.php?f=6&t=93510&hilit=Boston

Matt does very nice work!