Is there a better deal out there, than PSWPower's 36V 20Ah G70 battery with Samsung 48X or 50E 21700 cells?

[guerney]

Although I'm not in the market quite yet for a new battery, I'm wondering what cells PSWPower use in their temptingly inexpensive 36V 20Ah G70 model. On the product page:

Electric bicycle ebike Battery Hailong G70 G56 21700 18650 Cells Pack 48V 36V 17.5AH 15AH 20AH 13AH Bicycle Lithium ebike Battery Lithium fits1000W

Electric bicycle ebike Battery Hailong G70 G56 21700 18650 Cells Pack 48V 36V 17.5AH 15AH 20AH 13AH Bicycle Lithium ebike Battery Lithium fits1000W

www.pswpower.com

...there's this image with two Samsung 21700 cells, 50E and 48X...

...however, they don't state which cell their 36V G70 battery is comprised of. Looking at tests online, neither like high current drawn:

Test/review of Samsung INR21700-50E 5000mAh (Cyan)

Samsung INR21700-50E 5000mAh (Cyan) Official specifications: Standard discharge capacity: 4900mAh (0.2C discharge) Rated discharge capacity: 4753mAh (1C discharge) Charge voltage: 4.2V Nominal voltage: 3.6V Charging method: CC-CV Maximum charge current: 4900mA Maximum...

budgetlightforum.com

"The two cells are very well matches, but they do not like high current (I forget thermosensor on one of them, it survived, but must have been hot). "

...and the 48X pictured is grey, not green, so are PSWPoer's 48X cells fake?

https://lygte-info.dk/review/batteries2012/Samsung%20INR21700-48X%204800mAh%20(Gray)%20UK.html

"They are not high current batteries, but can handle a peak in current."

If I decide to buy a 36V 20Ah G70, I might have to dial power back from 720W, because PSWPower state:

"This 36V battery pack just fits 36V 0-500W motor,If your motor power over 500W , we can't provide warranty for this battery"

...which would be a bit of a bummer, because legal 720W is my new fave. Is there a better deal somewhere out there for a 36V battery comfy with high continuous current drawn?

What is it about these 48X or 50E packs which has PSWPower saying they won't guarantee their batteries with more than 13.89A drawn? (A=[W/V]).

 

[matthewslack]

It might be fine for your machine. When they say maximum 500W motor, they mean hub motor, which will have peak power somewhat higher than 500W, and will spend some of its time running inefficiently at low rpm demanding as much current as the controller will allow.

If you use your gears reasonably, to keep the motor spinning happily, your battery probably gets an easier time than that. Unless you are at 720W all the time these days?

720W is 20A, the 20Ah battery is 4p, so 5A per cell. The cell specification claims 9.8A max continuous current, so limiting to 5A and not all the time will probably be fine for battery longevity, and your 250W motor is fine for warranty purposes.

 

[guerney]

720W is 20A, the 20Ah battery is 4p, so 5A per cell. The cell specification claims 9.8A max continuous current, so limiting to 5A and not all the time will probably be fine for battery longevity, and your 250W motor is fine for warranty purposes.

Thanks for that, was wondering if they're displaying the warranty caveat because their 36V batteries use fake Samsung cells. Does seem a low price for 20Ah genuine Samsung celled, but prices have been dropping while I haven't been paying attention. This price for a 20Ah would have been absurd and suspicious to the extreme for Samsung cell populated, four years ago:

If you use your gears reasonably, to keep the motor spinning happily, your battery probably gets an easier time than that. Unless you are at 720W all the time these days?

I don't have a wattmeter, so don't know. But I do maintain a high RPM at all times, with the controller at 20A - too enjoyable not to. "Keep current" is 100% in firmware, so it's got to be as close to the 20A current limit sometimes, as my aged LG MH1 celled 19.2Ah battery is capable of continuously discharging current currently (bought and used since Nov 2019).

 

[Peter.Bridge]

Although I'm not in the market quite yet for a new battery, I'm wondering what cells PSWPower use in their temptingly inexpensive 36V 20Ah G70 model. On the product page:

Electric bicycle ebike Battery Hailong G70 G56 21700 18650 Cells Pack 48V 36V 17.5AH 15AH 20AH 13AH Bicycle Lithium ebike Battery Lithium fits1000W

Electric bicycle ebike Battery Hailong G70 G56 21700 18650 Cells Pack 48V 36V 17.5AH 15AH 20AH 13AH Bicycle Lithium ebike Battery Lithium fits1000W

www.pswpower.com

...there's this image with two Samsung 21700 cells, 50E and 48X...

...however, they don't state which cell their 36V G70 battery is comprised of. Looking at tests online, neither like high current drawn:

Test/review of Samsung INR21700-50E 5000mAh (Cyan)

Samsung INR21700-50E 5000mAh (Cyan) Official specifications: Standard discharge capacity: 4900mAh (0.2C discharge) Rated discharge capacity: 4753mAh (1C discharge) Charge voltage: 4.2V Nominal voltage: 3.6V Charging method: CC-CV Maximum charge current: 4900mA Maximum...

budgetlightforum.com

"The two cells are very well matches, but they do not like high current (I forget thermosensor on one of them, it survived, but must have been hot). "

...and the 48X pictured is grey, not green, so are PSWPoer's 48X cells fake?

https://lygte-info.dk/review/batteries2012/Samsung%20INR21700-48X%204800mAh%20(Gray)%20UK.html

"They are not high current batteries, but can handle a peak in current."

If I decide to buy a 36V 20Ah G70, I might have to dial power back from 720W, because PSWPower state:

"This 36V battery pack just fits 36V 0-500W motor,If your motor power over 500W , we can't provide warranty for this battery"

...which would be a bit of a bummer, because legal 720W is my new fave. Is there a better deal somewhere out there for a 36V battery comfy with high continuous current drawn?

What is it about these 48X or 50E packs which has PSWPower saying they won't guarantee their batteries with more than 13.89A drawn? (A=[W/V]).

Check the continuous discharge current (I think 25 amps on the one you were looking at) rather than the nominal wattage. So drawing 20 amps will be fine

 

[egroover]

I'm still running my BBS01 36v 250w motors at 15a, so peak power is 540w which I find is enough for me.
Does your motor run very hot at 20a, particularly in the summer, and, say, after a long hill climb ? I'd be a little concerned I might be shortening the life of the motor and/or my batteries running at 20a all the time. Does your 20" wheels compensate for this over my 29/700c wheels.
Perhaps 18 or 20a is okay without any motor overheating concerns in winter?
I just picked up from my usual AliExpress seller another Samsung celled Hailong 36v 20ah G56 downtube battery for about £180 delivered (about £150 after quidco cashback) so prices are good at the moment

 

[guerney]

Check the continuous discharge current (I think 25 amps on the one you were looking at) rather than the nominal wattage. So drawing 20 amps will be fine

There's an additional 1.8A for my always on lights.

 

[Peter.Bridge]

There's an additional 1.8A for my always on lights.

So you have a 3.2 A safety margin

 

[matthewslack]

Room for more lights...

 

[guerney]

I'm still running my BBS01 36v 250w motors at 15a, so peak power is 540w which I find is enough for me.

540W was enough me aswell, until the Gremlin Hill happening. Happily, climbing speed has increased. I did want to set levels differently, so I didn't end up habitually using 720W all the time, but the programming cable broke, and I haven't got around to setting up level 9 to 15A, and level 8 to 20A with the new one... because the first thing I always do after switching the bike on, is set to level 9 and leave it there. Can't be arriving at work sweaty. The plan is to click one level down to 8 during unpleasant emergencies, such as increasing uphill speed to stay ahead of talons and big scary teeth of Gremlins giving chase on foot. I'm probably killing my poor battery (will attempt cell bank voltage and capacity tests soon), but so far haven't noticed battery or motor running hotter, though they undoubtedly are, but not as hot as they'd get on a 29" wheeled bike. I'll get reprogramming levels with the new cable, because pissing 21.8A at the road is reducing range too much, I think. Deffo before weather warms up.

I just picked up from my usual AliExpress seller another Samsung celled Hailong 36v 20ah G56 downtube battery for about £180 delivered (about £150 after quidco cashback) so prices are good at the moment

Thanks, that's good to know. As a bonus, both your AliExpress shop and PSWPower use the same mount as my existing battery. Will my old battery survive long enough to see new batteries being given away for free?

I've just finished my latest conversion for some off road fun, brand new Forme Curbar Pro 29er MTB hardtail (£230 deal on ebay) with a Bafang BBS01b 250w 36v middrive (my new spare motor picked up on a deal at about £200 a couple of years ago) and 17.5ah battery (one of my existing).
Weighs in at 22kg and it's an XL frame and with a dropper seatpost. A smaller lighter donor bike should see you comfortably sub 20kg. The bbs01 is 85Nm and good range from the 630wh battery.

View attachment 61351

That looks great! Did you encounter any problems with the BB? Chainline?

I reckon a cadence sensored system would make things easier for the OP. Torque sensored seems far too much hard work for my liking (any work is too much for my liking). Of course the wonderful thing about the BBSXX(X) series is their programmability, when they're fully programmable: With that gearing, I imagine 720 legal Watts would get that bike up any hill no sweat.

I originally bought the bike not with the intention of converting, but couldn't resist the deal with the spec of the bike. The original chainwheel was a 32t, so I thought I would get chainline issues, but as it turned out, it's running sweeter with the stock 44t bafang chainwheel, which is closer to the chainstay and there's no need to go for a 40t lekkie one which I originally thought I might need. 10spd cassette 11-46t so plenty of low down gearing. Shifting is sweet and crisp and no apparent rubbing suggesting chainline issues. I think the larger 44t chainring has help in that regard compared to the original 32t
I even had to space out the motor with a 1mm spacer on the drive side as the motor was just touching the chainstay when tightened up.
Only completed the build this week, looking forward to giving it a proper run in the forrest over xmas
View attachment 61352

That bike looks great and very well sorted out, but now you're gonna need two spare motors.

So you have a 3.2 A safety margin

BMS is 22A - I reckon my battery's too old now, to consider uprating to make...

Room for more lights...