My Electrical people… I need battery help

[tomjasz]

My 48v Joyisi is a 13Ah battery and good for 30 miles hot-dogging

I read what must have been your first pack? I’m not being disingenuous and wanting to correct your decision. I think it’s important to have details. As you did by IDing the cells. Sadly we could buy shrink wrap battery labels today and change any cell to a brand name. It happens. A lot.

Making your feedback invaluable. Sourcing quality batteries is currently a nightmare. Sadly making me even more skittish. I need 6 batteries and no history with those available. It’s a goupbuy with friends.

 

[harryS]

Tell us about how you ride this bike. How fast do you go for the 10 miles of riding pleasure it gives you? Are you using pedal assist, or is it mostly throttle? A 500W bike like that on 48V10AH should cover at least 20 miles at 12 mph. Mine will anyway. A 10AH battery should take about 5 hours to recharge when empty. When you recharge this battery, does it recharge in like 2 hours?

In any case, I agree with Tomjasz. Unless you have a meter to check voltages on the charger and the battery, all you know is that you're getting 10 miles and it shuts off. However, this is a common story. I've read it many times in forums like this, and have had it happen to my own batteries, after I started fooling around with the cheap ones..

I'd have to say it's all unbalanced. It's shutting off at half capacity. Then all your LED's are dead. When the battery comes back on, your LED's show the total voltage around half capacity, However, there's at least one set of cells in there well under half capacity, close enough to minimum capacity that under load, the voltage sags low enough that the BMS shuts off your battery. When you hit the power switch, your battery always comes back to life, but any ebiking trips your BMS.

When this happens on a cheap battery, you're screwed. They don't put balance BMS in cheap batteries. It takes an expert to unbalance it, and no guarantee it won't wind up in the same fix in a month. So you'll have to buy a new battery, or call in the warranty on the one you just bought. If they have one, you'll want a voltmeter to prove that it's shuttig off at 45-47 volts, which is my prediction,

 

[bsingh897]

Tell us about how you ride this bike. How fast do you go for the 10 miles of riding pleasure it gives you? Are you using pedal assist, or is it mostly throttle? A 500W bike like that on 48V10AH should cover at least 20 miles at 12 mph. Mine will anyway. A 10AH battery should take about 5 hours to recharge when empty. When you recharge this battery, does it recharge in like 2 hours?

In any case, I agree with Tomjasz. Unless you have a meter to check voltages on the charger and the battery, all you know is that you're getting 10 miles and it shuts off. However, this is a common story. I've read it many times in forums like this, and have had it happen to my own batteries, after I started fooling around with the cheap ones..

I'd have to say it's all unbalanced. It's shutting off at half capacity. Then all your LED's are dead. When the battery comes back on, your LED's show the total voltage around half capacity, However, there's at least one set of cells in there well under half capacity, close enough to minimum capacity that under load, the voltage sags low enough that the BMS shuts off your battery. When you hit the power switch, your battery always comes back to life, but any ebiking trips your BMS.

When this happens on a cheap battery, you're screwed. They don't put balance BMS in cheap batteries. It takes an expert to unbalance it, and no guarantee it won't wind up in the same fix in a month. So you'll have to buy a new battery, or call in the warranty on the one you just bought. If they have one, you'll want a voltmeter to prove that it's shuttig off at 45-47 volts, which is my prediction,

Thank you very much for your detailed reply. I did reach out to the manufacturer and they will be offering a return/refund.

 

[tomjasz]

return/

Careful, shipping bad batteries can get you in hot water.

 

[bsingh897]

Careful, shipping bad batteries can get you in hot water.

Hmmm… how would you go about this? They gave me a prepaid return label

 

[tomjasz]

Hmmm… how would you go about this? They gave me a prepaid return label

Well, I'd make sure it goes ground service. But if it's not properly labeled and you declare the contents, it may not be accepted. That said batteries are shipped illegally every day. I just don't.

 

[tomjasz]

Sadly we could buy shrink wrap battery labels today and change any cell to a brand name. It happens. A lot.

I didn't dig in deeper but we can find brand name labels to rewrap.

 

[bsingh897]

This is a totally different battery I Have. Tried to fix it. It stopped charging and I reconnected the BMS and it started working but will cut off again. Here’s the video

 

[rich c]

Stop buying batteries off Amazon and eBay. You are getting exactly what you pay for and the range you paid for if you ride wide open throttle.

 

[bsingh897]

Stop buying batteries off Amazon and eBay. You are getting exactly what you pay for and the range you paid for if you ride wide open throttle.

Where is a better place to buy batteries?

 

[AHicks]

Long story short I bought this bike

And the battery stopped working… I plug it in the adapter and it will indicate green light like it’s fully charged but when I flip the switch on the battery and press the LED level indicator, it shows nothing. So either the power switch on the battery is broken or maybe the BMS.

But anyway, they gave me a credit to buy a new battery so I went and looked for a 48v 10AH battery because that’s what was on there originally.

I ended up buying this battery (48v 10 amp version)

Now I’m having issues with my bike shutting down From possibly a low voltage…

Initially everything is good, after maybe 10+ miles the bike will dead stop. I will then look at the battery indicator and it will show no charge, but when I power cycle the battery it will turn on and show it has 4 bars. Now when I try to ride it, it would always die under load or if I ride it long enough. So even if it shows about 70% charge it would still die. Here’s a video of it

Not sure if the controller is drawing too much power than the battery can handle? Idk really what’s causing the shut down.

If I do charge battery again everything will be fine even under load until maybe about 10+ miles

Are you absolutely SURE you are following the correct charge procedure? There is generally no need to turn the battery off prior to charging. Turning it off may be disconnecting the line to the charger.

 

[jkvt]

Where is a better place to buy batteries?

https://www.fthpower.com has a good name, from what I understand. Haven't used them before myself though. I think they may also sell on Amazon too, but maybe at a slight premium.

 

[tomjasz]

https://www.fthpower.com has a good name, from what I understand. Haven't used them before myself though. I think they may also sell on Amazon too, but maybe at a slight premium.

They were briefly a warranty center for EM3ev. We had very bad experiences. PLEASE when we make recommendations it's maybe best to have some experience rather than report other posts from what may be unvetted sources? Now is a tough time. Availability from trusted sources is abysmal.

EM3ev is a very good source, not sure on shipping. Our member @Jenny Mao 's company is still in quarantine I think.

@m@Robertson has a trusted USA source.

 

[Dorkyman]

This guy did a YouTube video testing numerous 18650 cells. He concluded that Chinese-sourced cells were utter junk. They may advertise a 48v14Ah pack when in reality it only does 48v5Ah.

 

[tomjasz]

This guy did a YouTube video testing numerous 18650 cells. He concluded that Chinese-sourced cells were utter junk. They may advertise a 48v14Ah pack when in reality it only does 48v5Ah.

Careful! China produces class A brand name cells. Generic cells are the issue.

 

[Ebiker01]

another cheap newbie wasting our collective intelligence &time.

BUY a proper ebike !!!

 

[EZrider]

another cheap newbie wasting our collective intelligence &time.

BUY a proper ebike !!!

That was brutal
Go crawl back under your rock

 

[Kayakguy]

Long story short I bought this bike

And the battery stopped working… I plug it in the adapter and it will indicate green light like it’s fully charged but when I flip the switch on the battery and press the LED level indicator, it shows nothing. So either the power switch on the battery is broken or maybe the BMS.

But anyway, they gave me a credit to buy a new battery so I went and looked for a 48v 10AH battery because that’s what was on there originally.

I ended up buying this battery (48v 10 amp version)

Now I’m having issues with my bike shutting down From possibly a low voltage…

Initially everything is good, after maybe 10+ miles the bike will dead stop. I will then look at the battery indicator and it will show no charge, but when I power cycle the battery it will turn on and show it has 4 bars. Now when I try to ride it, it would always die under load or if I ride it long enough. So even if it shows about 70% charge it would still die. Here’s a video of it

Not sure if the controller is drawing too much power than the battery can handle? Idk really what’s causing the shut down.

If I do charge battery again everything will be fine even under load until maybe about 10+ miles

Are you pedaling, or going entirely on throttle? A ten amp hour battery is pretty small (I have one just like it), and will poop out sooner than you might think it should if you aren't applying some leg input.

 

[SondorsMXS]

Everyone was a newbie once though.