K Battery, on Alibaba.

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dogman dan
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K Battery, on Alibaba.

Post by dogman dan » Aug 01, 2015 5:50 am

http://www.aliexpress.com/store/group/4 ... 77197.html

This battery was so cheap including the shipping, I just had to take a chance on it. If you are looking for a top quality battery, stop reading now. $400 shipped to the USA for a 48v 20 ah is simply never going to be the top drawer cells.

It's 13s, charges to 54.6v. So not as perky as a 14s pack, 4v slower. This matters more at the bitter end of the discharge, 4v less then too.

But if you need some range, have a controller that is 25 amps or less, and have no money, keep reading.

1 I was hoping to see the battery shipped legally. Labeled as a battery, properly packaged in fire resistant material, shipped as a Hazmat. It was NOT. Came in a box of foam, and the invoice just said charger. There was a charger in the box, but they forgot to mention they were air shipping a lithium battery. BAD BAD.

2 It did come very quick, about 6 days. So at least they had it in stock.

3 the packing was good for protecting the battery against damage. Lots of stiff foam, instead of air pillows that just pop on the plane at 30,000 ft.
K battery wrapper.jpg
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4 The charger that came with it is a piece of shit. I knew that would be the case just from the picture. But when I picked it up, it had something loose rattling around inside. Easy fix, the fan came loose. But still, I got what I paid for, a ten buck charger.

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dogman dan
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Re: K Battery, on Alibaba.

Post by dogman dan » Aug 01, 2015 5:51 am

Just the battery..jpg
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5 The battery is about 8.5 x 9 x 2.75 inches. NOT the shape I was expecting. It was supposed to be longer, and narrower. This is the one I bought.

I screwed up and did not buy the pack I meant to, which was supposed to have sanyo cells in it. Same price, I ended up clicking buy on a similar pack.

http://www.aliexpress.com/store/product ... 48308.html
Width witout the bms.jpg
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6 It came in good condition, and took a charge fine. Full discharge capacity test still not yet done. It takes a long ride! So far the pack has done one discharge of 16 ah, and another of 10 ah.

7 Sag under load is good, for my 22 amps controller. Under the heaviest loads of 1000w, it sags about 2.25v under load. Partly this is because the pack is large, so a 22 amps pull is only about 1c. That was the plan in the first place, cheap battery, limit discharge rate to about 1c. It sags less than my allcell battery under 1c, so I'm happy with that.

8 construction inside is ok. Spot welds don't look horrible, but not as good as you see in a tool battery pack. No name cells of course.
Spot welds 2.jpg
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dogman dan
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Re: K Battery, on Alibaba.

Post by dogman dan » Aug 01, 2015 5:52 am

9 The bms box is huge, but that could be good for letting it breathe, and shed it's heat. Tiny bms inside, if you need the whole pack to fit in a smaller space. Doesn't matter to me, I carry the battery in a large saddlebag.

Gotta lose that AC plug on the charger input. I won't be dumb enough to plug into the wall socket directly, but somebody will. meanwhile, I made an adapter to the same plug on all my chargers.
BMS 2.jpg
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10, Construction of the battery is good enough, lots of tape and some paper stuck with hot glue gives the pack some protection against chafing a hole riding in a box or bag. Like a screw head rubbing a spot, and then shorting the pack.

But even so, I still do what I always do, wrap the whole thing in a tight fitting box for additional protection. I like to use old political signs, that coroplast stuff.
K power battery in box.jpg
K power battery in box.jpg (123.18 KiB) Viewed 3464 times
All in all, I'm satisfied with the purchase. I got what I needed, a 20 ah battery on the cheap. It's fine for my bikes with the E bike kit motors on them, since they have only 22 amps controllers.

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imorton
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Re: K Battery, on Alibaba.

Post by imorton » Aug 01, 2015 7:39 am

Dogman Dan, thanks a million for a very detailed review.

As you probably know, we are all eager to also see the "long term" discharge tests and durability.

But for the time being, do enjoy the battery and the "rides" that it can give you... :)

IAN.
IAN from http://www.all-about-houseboats.com
GIO 500w scooter, LifePo4 48v 15Ah, WattsUp meter,

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Re: K Battery, on Alibaba.

Post by motomech » Aug 01, 2015 2:48 pm

So you are saying it's not exactly a "lemon", more like a banana?
Motomech

'03 Rocky Mountain Edge 2WD 260 Q100H frt and Ezee V1 rear 2 Elifebike 20A & 25A 9-FET controllers 12S/20Ah Multistar Lipo rear 5Ah Turnigy frt Luna Cyclops Extra lite Alex 24DM rims, 2.4 Holly Rollers run ghetto tubeless. 25 mph. Mean Well HLG-320H-48A
https://endless-sphere.com/forums/viewt ... =3&t=83430
'07 GT Idive 4 4.0, Q100C 201 12S LiPoly elifebike 9-FET 17A controller. 20 MPH.
https://endless-sphere.com/forums/viewt ... 8#p1237928

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dogman dan
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Re: K Battery, on Alibaba.

Post by dogman dan » Aug 02, 2015 7:01 am

Not a lemon so far. Just a cheap ass battery, that can handle 1c ok. The main news is simply that I did get shipped something.

Banana for scale has become a bit of a tradition on the net.

Just based on what I see so far, no reason to not think it will deliver 16 ah for a few years, at a 1c rate.

Let's clarify something though. I'm not endorsing it, it's not a cellman pack! But it's cheap, when cheap is what you need most.

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Re: K Battery, on Alibaba.

Post by imorton » Aug 02, 2015 7:27 am

Sounds like a legitimate purchase of a $400 battery (including shipping and a charger) that may give a 80% DOD at a 20Ah (1C rate) for maybe a few years.... Hmmmm, sound like a fairly decent deal, and you got what their website says.

Now, I have had my SunThing 48v 15Ah LifePo4 battery going onto to 2 years, cost me @ $350 (shipped & with charger) and I have had no problems with it so far. If it lasts me for another 1-2 years, than like you Dogman Dan, it has definitely solved my "simple/cheap/reliable" and Plug & Play battery needs.

I tried researching all the various battery types, and ways to build them, but let's be honest, in the grand scheme of things, I would rather ride than spend my time tinkering & tweaking a DIY battery build.

I'm sure if I had the tools, time, skill, and space to play & build my own battery I might have, but the convenience of ordering a "decent & low cost" solution is what the majority of users need here.

Keep us updated. IAN.

PS: How does this 48v 20Ah battery 18650 cell battery compares to a Ping/SunThing 48v 20Ah "pouch cell" battery in relation to physical size...?

Thanks.
IAN from http://www.all-about-houseboats.com
GIO 500w scooter, LifePo4 48v 15Ah, WattsUp meter,

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dogman dan
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Re: K Battery, on Alibaba.

Post by dogman dan » Aug 02, 2015 1:15 pm

5 pounds lighter, about half the size of 48v 20 ah ping. But that's not counting that ginormous bms box.

Size didn't matter much to me, But weight does. also I wanted to have a pack compatible to parallel with my allcell 13s pack.

http://www.aliexpress.com/store/product ... 23962.html

That is the one I bought, but it's different in size and shape from the picture. Dimensions in the spec list are wrong.

Weight including my protective box is 15 pounds. Naked cells might be 10.56 pounds.

Max discharge rate 60 amps, sure, if you want to beat it to death fast.



• Long lifespan cycle times: 1,200
• No memory effect
• Nontoxic, environmental friendly



• Charging end voltage: 54.6V
• Discharge cut off voltage: 36.4V
• Typical voltage: 48V
• Nominal capacity: 20Ah
• Maximum continuous discharge current: 40A
• Peak discharge current: 60A
• Cell Combination: 13 series
• Dimensions: 260 x 160 x 80mm
• Charging current: 3A
• Maximum charging current: 8A Compatible
• Charge Mode: CC/CV
• Net weight: 4.8 Kg
• Working temperature range: -20 to 60°c
• Storage temperature: -20 to 50°c
• Internal resistance: <150ohm

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dogman dan
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Re: K Battery, on Alibaba.

Post by dogman dan » Aug 03, 2015 6:08 am

Tried to do a 100% discharge test yesterday, and got 17.8 ah out of it.

But the battery bms did not stop it, the E BikeKit controller started to LVC. So that's good enough for me, 18 ah more or less available for use. Stopped at about 41v under load, about 41.5 unloaded, since I was milking out the last bit slow by then.

Again, I don't endorse this vendor, other than to say it was cheap, and it runs ok at 1c. If I don't go pound it into dogshit, I see no reason it should not last a few seasons. Since I don't commute daily anymore, that might be 300 cycles in two years, or less. Anything less than 2 bucks a ride will suit me fine for economy. A car trip to the grocery is 7 bucks. So this battery can make each trip pay me five bucks if it lasts 2 years. If it goes three, then more like 6 bucks saved per trip.

I don't need max cycles, or max distance for my current riding needs. If I still commuted 100-200 miles a week, I'd need a battery with much higher quality cells in it for sure.

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Re: K Battery, on Alibaba.

Post by striider » Sep 10, 2015 10:56 am

"Banana for scale", love it! :lol:

I am commuting on a similar battery. We shall see how it goes. 1400 miles so far, and no noticeable decline in performance.

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dogman dan
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Re: K Battery, on Alibaba.

Post by dogman dan » Jan 22, 2016 8:13 am

FWIW, this particular supplier has closed it's store on alibaba.

The pack still running fine, though not a lot of use on it since it's winter now.

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Re: K Battery, on Alibaba.

Post by dogman dan » Mar 08, 2016 6:20 am

Capacity now down to 16.2 ah, when run till the bms pops. Not good. Warm enough now too, that it cannot be just cool weather knocking back capacity. I might get a few wh more out of it in really hot weather, but not much more.

Cheap ass battery, but like the old cheap ass lifepo4's of 2009, figure when you buy 20 ah, you are getting 15. About what I expected, but of course hoped to win the lotto and do better. I'd hoped for at least a year of getting close to the original 90% capacity.

Just went back to lipo for this springs battery buy, at least I can pull hard on them.

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Re: K Battery, on Alibaba.

Post by imorton » Mar 08, 2016 8:53 am

Thanks for the updates, it's always good to know how much AND how long these batteries "put out"....

Quality is quality, and cheap is usually cheap.

Atlas you are getting some use out of it, and it just didn't die on you... :)

IAN.
IAN from http://www.all-about-houseboats.com
GIO 500w scooter, LifePo4 48v 15Ah, WattsUp meter,

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dogman dan
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Re: K Battery, on Alibaba.

Post by dogman dan » Mar 11, 2016 7:28 am

Hoping it will settle in, an at least dish out 15 ah for a few years. If not, I just took delivery on 20 ah of hobby king lipo. Swore I was done with lipo, but it's sure cheap in the 20c stuff.

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Re: K Battery, on Alibaba.

Post by emaayan » Apr 30, 2017 1:30 pm

i think it would be advisable to back link to the current story ...
Trek 7.7 fx, 22.5" frame, 38x700c,10 gears.
ecospeed mid drive 1300 watt engine, max speed 45 kph.
battery1: 48v 14 ah, frame mounted battery, range 40km.
battery2(spare) 52v 10ah frame mounted bag, range, 30km.

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