Real battery capacity.

Robert Kelly

New Member
Hello fellow e-bikers, I buy my batteries from Aliexpress, really cheap.Can get a 10,000mah pack (48v) for around £50.
They have loads of packs of varying capacities, there highest claiming to be 100,000 mah, but frankly I don't believe it.
I brought a Dolidada pack, the sticker says 36,000 mah but it ain't.Its true capacity is about 10,000mah but at £50 it is
still a good value battery.My question is, how do I know if I buy a battery from Aliexpress, what the true capacity is?
I would like to experiment with batteries maybe buy a few more, perhaps even a 52volt for more power, but I must
know the true capacity beforehand, I need to be looking at a battery of about 30,000 mah capacity, that will get me about
15miles out of my e-bike, my current 2, 10,000mah get me about 5 miles each. I notice ebikes on line advertised saying they
get about 30 miles range from such a battery, that would be amazing.Why is my bike only doing 5 miles?
Anyway thanx for any tips and advice.
Rob
 

Timpo

Well-Known Member
Hello fellow e-bikers, I buy my batteries from Aliexpress, really cheap.Can get a 10,000mah pack (48v) for around £50.
They have loads of packs of varying capacities, there highest claiming to be 100,000 mah, but frankly I don't believe it.
I brought a Dolidada pack, the sticker says 36,000 mah but it ain't.Its true capacity is about 10,000mah but at £50 it is
still a good value battery.My question is, how do I know if I buy a battery from Aliexpress, what the true capacity is?
I would like to experiment with batteries maybe buy a few more, perhaps even a 52volt for more power, but I must
know the true capacity beforehand, I need to be looking at a battery of about 30,000 mah capacity, that will get me about
15miles out of my e-bike, my current 2, 10,000mah get me about 5 miles each. I notice ebikes on line advertised saying they
get about 30 miles range from such a battery, that would be amazing.Why is my bike only doing 5 miles?
Anyway thanx for any tips and advice.
Rob
The cheap no brand cells typically do not show true capacity.

People on YouTube have been checking it with battery capacity checker.

If you get a 48v 20Ah battery for example, they're usually something like 6 or 7Ah.

Just stick to Samsung, LG, Panasonic, etc
 

Hectors Ghost

Active Member
How so?

Most AliExpress seller will either tell you, or let you pick which cells you want.
I agree that they will tell you "what you want to hear", but not necessarily the truth of what you are getting regardless of the cells' wrappers. Maybe EM#ev will start building large packs again someday.
 

Robert Kelly

New Member
I think the best strategy is, if it cost's £50 or so I will assume it's 10,000mah. A more expensive battery claiming to be 20,000mah of say £70 or so Will be 20,000mah. It's true you get what you pay for.Had a look at DH gate, good site but a bit pricey on packs.
 

Timpo

Well-Known Member
I agree that they will tell you "what you want to hear", but not necessarily the truth of what you are getting regardless of the cells' wrappers. Maybe EM#ev will start building large packs again someday.
What do you mean by that?

It sounds like you're under the assumption that every single seller on AliExpress is a scammer and they will never have real Samsung cells, so might as well go for the cheapest cells possible.

Why would you knowingly purchase bad cells for super cheap?
That would be a complete waste of money.
 

Hectors Ghost

Active Member
It sounds like you're under the assumption that every single seller on AliExpress is a scammer ...
It's pretty straight forward... if you haven't noticed I don't mince words. I have always been a firm believer that you get what you pay for. Buy cheap... own cheap. I haven't and won't ever use Ali and don't believe the CCP is prone to allow purchasing cells from Japan.
 

Timpo

Well-Known Member
It's pretty straight forward... if you haven't noticed I don't mince words. I have always been a firm believer that you get what you pay for. Buy cheap... own cheap. I haven't and won't ever use Ali and don't believe the CCP is prone to allow purchasing cells from Japan.
Cheap doesn't necessarily mean bad.. yeah, generally you probably will get what you paid for, but I found that there are tons of real Samsung 35E powered batteries on AliExpress.

Low price could mean, cutting middle person, cutting warehouse cost, more efficient production, lower labor cost, etc
Do you want to be paying for middle person? I don't think so.

My stock Juiced 26F battery wasn't nowhere near good as Eunorau 35E battery from AliExpress.

I watch EbikeSchool on YouTube..

Micah from EbikeSchool buy LOTS of stuff on AliExpress, and he reviews tons of products including batteries.
I trust his words because he seems to know what he's talking about. At least way more than I do 😁

 

Hectors Ghost

Active Member
Cheap doesn't necessarily mean bad... Low price could mean, cutting middle person, cutting warehouse cost, more efficient production, lower labor cost, etc
My stock Juiced 26F battery wasn't nowhere near good as Eunorau 35E battery from AliExpress.
It most certainly does to me. I will buy generic products at times but nothing electronic. Occams Razor would suggest that it's far more likely that knock-off cells are being produced to resemble quality batteries than to believe that they can get discounts on batteries from Japanese companies, or that China can get a lower labor cost than they take advantage of now, or save anything on storage costs... etc. Your Juiced battery is a POS also, where do you think it and it's components were produced? Ebike manufactures have/do/will always cut corners to reduce pricing and even more so on components you can't verify. The proof of the pudding is in the eating. It's a simple thing to compare battery performance, take two similar packs charged to the same voltage, and ride the same route.
 

Timpo

Well-Known Member
It most certainly does to me. I will buy generic products at times but nothing electronic. Occams Razor would suggest that it's far more likely that knock-off cells are being produced to resemble quality batteries than to believe that they can get discounts on batteries from Japanese companies, or that China can get a lower labor cost than they take advantage of now, or save anything on storage costs... etc. Your Juiced battery is a POS also, where do you think it and it's components were produced? Ebike manufactures have/do/will always cut corners to reduce pricing and even more so on components you can't verify. The proof of the pudding is in the eating. It's a simple thing to compare battery performance, take two similar packs charged to the same voltage, and ride the same route.
I agree that Juiced does not have the best reputation when it comes to reliability or customer service, Tora (owner of Juiced) realizes that and on his website, he made a statement to improve his service.

But I am not sure if Juiced uses counterfeit Samsung cells, all I can do is trust that they won't take such silly risks.
 

Thomas Jaszewski

Well-Known Member
I have a couple of 26f packs. Great cell for 36v 15a like the BBS01. I have a 48v 26F 20Ah as well. Again for 20A or less.
The market and forums like this and endless_sphere have lots of reviews and the trusted sources are discussed. I prefer EM3ev over most but have a couple of budget builds where I specified the cells and BMS that have served me well too.
 

harryS

Well-Known Member
I measure my battery capacity with a $12 wattmeter from ebay ($20 on amazon). First I have to run the pack empty. Then I connect the meter when it's being recharged. That tells me how many AH are needed to charge it, and that is close enough to the AH that is in the pack. It can also be connected on the bike and read how many AH went out of the battery,

It's powered off either the battery or charger, so when used on the bike, if the battery shuts off, you lose all the data. Also some batteries and a few chargers shut at full charge. So you want make sure the device emains powered. It has an input attach a little battery. All it needs is 3V.


watts (1 of 1).JPG


Most of my batteries were marked honestly. They deliver close to advertised capacity. For me 90% is close enough. I prefer not to run my packs empty. so it's a measurement I might do once a year to check on a packs ageing.
 

CityExplorer

Well-Known Member
I measure my battery capacity with a $12 wattmeter from ebay ($20 on amazon). First I have to run the pack empty. Then I connect the meter when it's being recharged. That tells me how many AH are needed to charge it, and that is close enough to the AH that is in the pack. It can also be connected on the bike and read how many AH went out of the battery,

It's powered off either the battery or charger, so when used on the bike, if the battery shuts off, you lose all the data. Also some batteries and a few chargers shut at full charge. So you want make sure the device emains powered. It has an input attach a little battery. All it needs is 3V.


.... Most of my batteries were marked honestly. They deliver close to advertised capacity. For me 90% is close enough. I prefer not to run my packs empty. so it's a measurement I might do once a year to check on a packs ageing.
If you want to measure the real capacity, you need to measure the Wh as the battery is discharged. The Ah ratting will not accurately reflect the battery capacity between various cells, and actually the Ah charged capacity is not a very good indication of even the discharge Ah rating, but never mind that because for the ebike batteries you really want the Wh rating for typical usage.
 

harryS

Well-Known Member
The meter will show WH too. It cycles between AH, WH, minimum voltage, and max amperes.

The WH measurement during riding was never consistent. I would see 10-20% variation with different meters (I have three) but the AH always agreed. Some of that is probably due to calibration of the internal voltmeter, which is not accurate. However, the AH was the same when I put all three in series, so that's all I need.

I've also done enough AH-out and AH-in to know it's close enough for ebike work.