Would either or both of these ebike batteries be OK ?

[HansTrio]

Any reason this would not be a reasonable choice for a 1000watt ebike kit ? It's an 18650 based battery.
Sold on ebay.

https://www.ebay.com/itm/402774747697

Or...would a lithium Ion battery like this be a better choice ?

https://www.ebay.com/itm/313541943085

 

[Bitmugger]

My issue would be can you trust the vendor. Your vendor is new to eBay and has a minimal history.
I would be worried about counterfeit cells, non-brand name cells, used cells and misleading claims about longevity and capacity.

I've been recommending Aijiu Power and contacting @Jenny Mao who's a user here for batteries. You'll get a good price with name brand cells. She can quote you prices with or without a charger for the specs you want and include shipping and dealing with customs and stuff. Her email is [email protected].

I'd honestly avoid that vendor, it seems like the majority of his limited sales are for stickers and small dollar items which might be just to start building a reputation. You would literally be his first purchase over $100 and only his second purchase over $50.

 

[HansTrio]

My issue would be can you trust the vendor. Your vendor is new to eBay and has a minimal history.
I would be worried about counterfeit cells, non-brand name cells, used cells and misleading claims about longevity and capacity.

I've been recommending Aijiu Power and contacting @Jenny Mao who's a user here for batteries. You'll get a good price with name brand cells. She can quote you prices with or without a charger for the specs you want and include shipping and dealing with customs and stuff. Her email is [email protected].

I'd honestly avoid that vendor, it seems like the majority of his limited sales are for stickers and small dollar items which might be just to start building a reputation. You would literally be his first purchase over $100 and only his second purchase over $50.

Thanks.
I guess I knew the consensus but was hoping for a miracle

I also looked at BtrPower on Amazon. $370 for 48v 20Ah and I've heard good reviews on that vendor.

I'll also try the contact you suggested.

Many thanks !

 

[Bitmugger]

Thanks.
I guess I knew the consensus but was hoping for a miracle

I also looked at BtrPower on Amazon. $370 for 48v 20Ah and I've heard good reviews on that vendor.

I'll also try the contact you suggested.

Many thanks !

There's lots of good vendors, I feel others will chime in with some good sources too. If you search my posts you'll see I have a huge 25ah battery coming from Aijiu that I am excited to receive.

 

[Rin]

The first question to ask is what brand cells and the second question is can you trust the vendor to tell the truth.

 

[harryS]

Jeez, they are counterfeiting Unit Pack Power these days? I know he doesn;t say they are Unit Pack Power, just UPP. A lot of people here hate UPP batteries, but they must get some respect if people are putting their logo on their batteries. If you buy a real 48V20Ah UPP battery from UPP in China via aliexpress, it's $414, not $315 on ebay.

Your samples, by the way, are big and heavy. They are hard to package into an ebike w/o stuffing into a triangle bag. And being unwieldy, you have to be careful of banging them up.

I would be looking at something like this for 1000W.
https://www.aliexpress.com/item/32832124801.html?spm=a2g0o.detail.1000023.2.d348216amQNxiWNxiW[/URL

 

[HansTrio]

I accidentally posted this in another thread....I meant to post it here.
I ended up buying this battery and tested it.

So the test results are in........

I used a 48v inverter and measured the results with a reasonably accurate MNJ MOTOR DC Multi function Battery Monitor Meter with 100Amp shunt
The load was 16.1Amps total and consisted of a small heater and an air purifier.
Ambient room temperature was 75F and relative humidity 38%. The battery started at room temp of 75F for this test.

Here is the inverter with battery next to it

And here are the results.......
The final Amps was due of course to voltage drop as the battery voltage drops, current rises proportionately

So I got 18.5Ah at a discharge rate of 16 amps
The battery is billed as 48v 20Ah.
But as you may know, manufacturers are pretty much free to rate their batteries as they please.
I found that if I discharge this battery pack at 1amp it does indeed yield 20Ah. But you cannot operate any ebike on 1amp.
So I assume their rating scale is based on a discharge rate of 1amp or 0.05C
Walmart Lead Acid batteries are rated at a 122hour rate so as I said, ratings are all over the place and don't mean much in and of themselves.

The question becomes......is this amount of capacity at 48v worth $320.00 ?
I'm not sure how many people actually run a quality capacity test on their battery so this may not be readily available information.
But I suspect it's very much par for the course and that extra 1.5Ah would cost a pretty good premium.
I priced out good 18650 cells that would give me 20Ah at 48v and I think it came out to about the same, but I'd still have to buy a BMS.
18650 cells do not have anywhere near the cycle life of a LiFePO4. Roughly 500 cycles for the 18650's and several thousand for the LiFePO4 pack depending on care and use.

I hope this information is beneficial to someone.

View attachment 90700

https://www.ebay.com/itm/262991429972?_trkparms=aid=111001&algo=REC.SEED&ao=1&asc=20160727114228&meid=acec816e9b564d548eae6c5dba000905&pid=100290&rk=1&rkt=4&sd=262991429972&itm=262991429972&pmt=1&noa=1&pg=2506613&_trksid=p2506613.c100290.m3507

48V20AH LiFePO4 Battery Power Pack for Scooter Ebike Rechargeable Motorcycle​

 

[Bitmugger]

Quick note. It was billed as a 20ah and you got 18.5Ah but the battery capacity that a pack is rated at is universally calculated as the sum of the cell capacities in parallel. So for a 18650 rated at 2900mah and a 13s5p pack the capacity would be marketed as a 5 x 2900mah = 14.5ah. But that capacity on the cells is measured from the peak voltage down to the specified cut off voltage of the datasheet usually ~2.65v. You'll never see that capacity in real life unless you have no BMS on your battery pack and an ebike controller that has no cut-off. So measuring 18.5ah seems reasonable since you only discharged each cell to 3.57v. No idea what brand your cells are but for a Samsung INR18650 discharging to 3.57v is great as that's right at the knee of the discharge graph where voltage will be dropping sharply if more power is used, but it means you never fully get all the capacity of the cells.

So getting 18.5ah real world from a battery pack rated 20ah seems fine to me.

I have a battery coming that is 25ah on the datasheets but the engineering report only achieved 24.1ah in discharge tests with the BMS in place. This is because firstly the Samsung 50E cells are really 4900mah+ not 5000mah+ so the best the pack can hope for is 24.5ah to 25ah and then the BMS cuts out at 36.5v so the cells never get drained fully hence 24.1ah real world capacity but it's still a 25ah battery pack.

 

[HansTrio]

Quick note. It was billed as a 20ah and you got 18.5Ah but the battery capacity that a pack is rated at is universally calculated as the sum of the cell capacities in parallel. So for a 18650 rated at 2900mah and a 13s5p pack the capacity would be marketed as a 5 x 2900mah = 14.5ah. But that capacity on the cells is measured from the peak voltage down to the specified cut off voltage of the datasheet usually ~2.65v. You'll never see that capacity in real life unless you have no BMS on your battery pack and an ebike controller that has no cut-off. So measuring 18.5ah seems reasonable since you only discharged each cell to 3.57v. No idea what brand your cells are but for a Samsung INR18650 discharging to 3.57v is great as that's right at the knee of the discharge graph where voltage will be dropping sharply if more power is used, but it means you never fully get all the capacity of the cells.

So getting 18.5ah real world from a battery pack rated 20ah seems fine to me.

I have a battery coming that is 25ah on the datasheets but the engineering report only achieved 24.1ah in discharge tests with the BMS in place. This is because firstly the Samsung 50E cells are really 4900mah+ not 5000mah+ so the best the pack can hope for is 24.5ah to 25ah and then the BMS cuts out at 36.5v so the cells never get drained fully hence 24.1ah real world capacity but it's still a 25ah battery pack.

Good information. Thanks
Do you know the weight of your inbound 25Ah pack ?

Mine is 14lbs or 6.35kg. A bit on the heavy side maybe.
What makes my battery much more tolerable to me is the fact that it is a 1 Kw battery pack so it will also be very handy in case of power outages. Dual purpose.

 

[Gionnirocket]

I accidentally posted this in another thread....I meant to post it here.
I ended up buying this battery and tested it.

So the test results are in........

I used a 48v inverter and measured the results with a reasonably accurate MNJ MOTOR DC Multi function Battery Monitor Meter with 100Amp shunt
The load was 16.1Amps total and consisted of a small heater and an air purifier.
Ambient room temperature was 75F and relative humidity 38%. The battery started at room temp of 75F for this test.

Here is the inverter with battery next to it
View attachment 90732

And here are the results.......
The final Amps was due of course to voltage drop as the battery voltage drops, current rises proportionately
View attachment 90733

So I got 18.5Ah at a discharge rate of 16 amps
The battery is billed as 48v 20Ah.
But as you may know, manufacturers are pretty much free to rate their batteries as they please.
I found that if I discharge this battery pack at 1amp it does indeed yield 20Ah. But you cannot operate any ebike on 1amp.
So I assume their rating scale is based on a discharge rate of 1amp or 0.05C
Walmart Lead Acid batteries are rated at a 122hour rate so as I said, ratings are all over the place and don't mean much in and of themselves.

The question becomes......is this amount of capacity at 48v worth $320.00 ?
I'm not sure how many people actually run a quality capacity test on their battery so this may not be readily available information.
But I suspect it's very much par for the course and that extra 1.5Ah would cost a pretty good premium.
I priced out good 18650 cells that would give me 20Ah at 48v and I think it came out to about the same, but I'd still have to buy a BMS.
18650 cells do not have anywhere near the cycle life of a LiFePO4. Roughly 500 cycles for the 18650's and several thousand for the LiFePO4 pack depending on care and use.

I hope this information is beneficial to someone.

View attachment 90700

https://www.ebay.com/itm/262991429972?_trkparms=aid=111001&algo=REC.SEED&ao=1&asc=20160727114228&meid=acec816e9b564d548eae6c5dba000905&pid=100290&rk=1&rkt=4&sd=262991429972&itm=262991429972&pmt=1&noa=1&pg=2506613&_trksid=p2506613.c100290.m3507

48V20AH LiFePO4 Battery Power Pack for Scooter Ebike Rechargeable Motorcycle​

I would assume (hope) that a battery's capacity would be determined operating under a load of 1C
Isn't that the point of determining C?

 

[HansTrio]

I would assume (hope) that a battery's capacity would be determined operating under a load of 1C
Isn't that the point of determining C?

Not really. Very few batteries are capacity rated at 1C. Normally much lower than 1C. like .1C or .2C or less.

Walmart group 29C large Marine deep cycle batteries are rated at 825CCA and 122Ah (at ONE AMP discharge rate)

Most batteries are not frequently used at a discharge rate of 1C. Vehicle starting batteries may be the exception. And that's only for a few seconds.
1C simply designates a discharge rate equal to the batteries capacity. So that would mean discharging a 100Ah battery at 100Amps for 1 hour.
I would say you would quickly ruin most batteries if you discharged them 80% at their 1C rating frequently.

C ratings are used to inform the end user as to the batteries capabilities and limitations more so that a guide on "how" to use the battery.

You could take 10 different 100Ah batteries and they could all have different capacities at different discharge rates. And most batteries are not
advertised as having their capacity at 1C. Most are rated to their maximum deliverable capacity at far less than 1C.
In other words, few batteries would provide their rated capacity at their 1C rate.
Think about who decides the capacity of a battery......it's the manufacturer or engineer more so than the battery...and they decide it on their terms.
such as a 100Ah battery.....that will only provide that 100Ah at a discharge rate of 0.2C or 20% of rated capacity.

There are no uniform international standards dictating how battery manufacturers must determine and advertise their capacity ratings.
so hundreds of different metrics are used. Some more honest than others, but few outright wrong per se.
If international law stated that all batteries MUST be capacity rated at 1C it would be better for the consumer.

If that happened, you'd see nearly every battery on the market advertise a lower capacity.

 

[EMGX]

I accidentally posted this in another thread....I meant to post it here.
I ended up buying this battery and tested it.

So the test results are in........

I used a 48v inverter and measured the results with a reasonably accurate MNJ MOTOR DC Multi function Battery Monitor Meter with 100Amp shunt
The load was 16.1Amps total and consisted of a small heater and an air purifier.
Ambient room temperature was 75F and relative humidity 38%. The battery started at room temp of 75F for this test.

Here is the inverter with battery next to it
View attachment 90732

And here are the results.......
The final Amps was due of course to voltage drop as the battery voltage drops, current rises proportionately
View attachment 90733

So I got 18.5Ah at a discharge rate of 16 amps
The battery is billed as 48v 20Ah.
But as you may know, manufacturers are pretty much free to rate their batteries as they please.
I found that if I discharge this battery pack at 1amp it does indeed yield 20Ah. But you cannot operate any ebike on 1amp.
So I assume their rating scale is based on a discharge rate of 1amp or 0.05C
Walmart Lead Acid batteries are rated at a 122hour rate so as I said, ratings are all over the place and don't mean much in and of themselves.

The question becomes......is this amount of capacity at 48v worth $320.00 ?
I'm not sure how many people actually run a quality capacity test on their battery so this may not be readily available information.
But I suspect it's very much par for the course and that extra 1.5Ah would cost a pretty good premium.
I priced out good 18650 cells that would give me 20Ah at 48v and I think it came out to about the same, but I'd still have to buy a BMS.
18650 cells do not have anywhere near the cycle life of a LiFePO4. Roughly 500 cycles for the 18650's and several thousand for the LiFePO4 pack depending on care and use.

I hope this information is beneficial to someone.

View attachment 90700

https://www.ebay.com/itm/262991429972?_trkparms=aid=111001&algo=REC.SEED&ao=1&asc=20160727114228&meid=acec816e9b564d548eae6c5dba000905&pid=100290&rk=1&rkt=4&sd=262991429972&itm=262991429972&pmt=1&noa=1&pg=2506613&_trksid=p2506613.c100290.m3507

48V20AH LiFePO4 Battery Power Pack for Scooter Ebike Rechargeable Motorcycle​

I have the 48v 10ah version of that battery. I charged it fully yesterday and so far have ridden two 23+ mile loops of a ride from home on that charge for a total of 46.5 miles with 3400ft elevation gain without hitting the voltage drop off. I'm going to try repeating the loop until it gives out. I hope I don't get stuck without assist on a hilly portion.

 

[HansTrio]

I have the 48v 10ah version of that battery. I charged it fully yesterday and so far have ridden two 23+ mile loops of a ride from home on that charge for a total of 46.5 miles with 3400ft elevation gain without hitting the voltage drop off. I'm going to try repeating the loop until it gives out. I hope I don't get stuck without assist on a hilly portion.

That's excellent EMGX

What type of motor and wattage are you using and did you do much peddle assist?

 

[EMGX]

Tongsheng TSDZ2 48v 750w mid drive, supposed to peak less than 1000W. I put as much effort in as I can but use assist liberally on grades, no throttle. I'd prefer a lighter non-assist bike if it wasn't for the hills. Also have a gravel bike with a Yamaha PW-SE mid drive and to me the Tongsheng is very comparable - I have two, a 36v 500w and the 48V, both have been battery efficient for my use, as has the Yamaha.

 

[Bitmugger]

Good information. Thanks
Do you know the weight of your inbound 25Ah pack ?

Mine is 14lbs or 6.35kg. A bit on the heavy side maybe.
What makes my battery much more tolerable to me is the fact that it is a 1 Kw battery pack so it will also be very handy in case of power outages. Dual purpose.

I don't know the weight but @Jenny Mao probably will, she sold it to me and packed it herself, lol. She works for Aijiu and is a member here. If Jenny doesn't I'll be sure to weigh it on arrival and post it.

 

[HansTrio]

I hope BtrPower is better than UPP.

 

[tomjasz]

https://www.intertek.com/energy-storage/un-transportation-testing/

 

[Gionnirocket]

Not really. Very few batteries are capacity rated at 1C. Normally much lower than 1C. like .1C or .2C or less.

Walmart group 29C large Marine deep cycle batteries are rated at 825CCA and 122Ah (at ONE AMP discharge rate)

Most batteries are not frequently used at a discharge rate of 1C. Vehicle starting batteries may be the exception. And that's only for a few seconds.
1C simply designates a discharge rate equal to the batteries capacity. So that would mean discharging a 100Ah battery at 100Amps for 1 hour.
I would say you would quickly ruin most batteries if you discharged them 80% at their 1C rating frequently.

C ratings are used to inform the end user as to the batteries capabilities and limitations more so that a guide on "how" to use the battery.

You could take 10 different 100Ah batteries and they could all have different capacities at different discharge rates. And most batteries are not
advertised as having their capacity at 1C. Most are rated to their maximum deliverable capacity at far less than 1C.
In other words, few batteries would provide their rated capacity at their 1C rate.
Think about who decides the capacity of a battery......it's the manufacturer or engineer more so than the battery...and they decide it on their terms.
such as a 100Ah battery.....that will only provide that 100Ah at a discharge rate of 0.2C or 20% of rated capacity.

There are no uniform international standards dictating how battery manufacturers must determine and advertise their capacity ratings.
so hundreds of different metrics are used. Some more honest than others, but few outright wrong per se.
If international law stated that all batteries MUST be capacity rated at 1C it would be better for the consumer.

If that happened, you'd see nearly every battery on the market advertise a lower capacity.

Lies!..... Lies!.... I feel so defiled!
Yes a 1C test is what should be standardized... Or at the very least a typical load for which the pack is described as and/or intended use.

 

[tomjasz]

You'll get a good price with name brand cells.

has anyone opened their packs to confirm cells used? Sadly rebranding is far too common. I'm not implying your source would do that but it's always a concern.

 

[tomjasz]

I hope BtrPower is better than UPP.

Based on? But UPP is a low bar.