Ned help with 48v 1000w bike

[1000W48V]

This is my problem........


Everything was working great......parked the bike outside for a couple of weeks, brought it in to charge. However, after having been charged, I took it out for a spin and almost immediately the motor cut power.......only to be restored several seconds later.....which again would cut power.......and the cycle continued. At first I thought my Lithium battery must have ended it's life, but quickly realized it was still cranking out 52v after putting the voltmeter on it. I admit I don't know much about or how a controller functions, but I can't help but wonder if it is the controller cutting power to the motor?...........as it's hard for me to believe that the motor itself would be at fault.

If there is ANYONE out there who may know what may be causing this.......I would very much appreciate any input you may have! It would greatly be appreciated!!!

 

[rmasa]

Not sure what system we talking about, but sounds like the brake cutoff sensor.

 

[harryS]

What happens if you lift the wheel off the ground? Will the motor run w/o cutting power?

 

[1000W48V]

What happens if you lift the wheel off the ground? Will the motor run w/o cutting power?

Yes, the motor seems to run fine.............I guess it only cuts out under a load......but I checked the 48v lithium battery and it's putting out 52-50v after motor cutting out.

 

[Trail Cruiser]

How old is the battery?

 

[1000W48V]

3 yrs

 

[1000W48V]

Actually, the battery is only a yr and a half old

 

[bikerjohn]

This is my problem........


Everything was working great......parked the bike outside for a couple of weeks, brought it in to charge. However, after having been charged, I took it out for a spin and almost immediately the motor cut power.......only to be restored several seconds later.....which again would cut power.......and the cycle continued. At first I thought my Lithium battery must have ended it's life, but quickly realized it was still cranking out 52v after putting the voltmeter on it. I admit I don't know much about or how a controller functions, but I can't help but wonder if it is the controller cutting power to the motor?...........as it's hard for me to believe that the motor itself would be at fault.

If there is ANYONE out there who may know what may be causing this.......I would very much appreciate any input you may have! It would greatly be appreciated!!!

Your description reads just like the experience I had with my bike. After 300 recharge cycles providing reliable power for more than 5100 miles, the controller started cutting off power to the motor early into the ride while the battery still registeres adequate power levels. The diagnosis opined in this forum was "faulty cells in the battery pack" and battery failure due to age. Lithium-ion battery cells have a limited lifespan. A Battery's advertised lifespan can be misleading. While an optimal lifespan may be listed as retaining 80%+ capacity after 1000 recharge cycles, real lifespan is limited by actual use conditions.
I sent my battery out to RPE for diagnosis and rebuild. The refurbishment will upgrade the battery to 15Ah from the original 12Ah.
Rechargeable Power Energy Inc.
6585 Arville St.
Las Vegas, NV 89118-6826

Tel.: (888) 456-9410 ext 109
Cell.: (757) 303-1441
Fax: (702) 749-5906
email: [email protected]
Web: www.rechargeablepowerenergy.com

 

[Trail Cruiser]

With the battery fully charged and connected to a voltage meter, see if the voltage quickly dips down (44-47 volts) when applying power. If it does, then you need a new battery. Another options of battery source are from Luna cycles,
https://lunacycle.com/48v-18650-ebike-battery-pack/
bike kit
https://www.ebikekit.com/collections/batteries
electric rider
(Link Removed - No Longer Exists)
electric bike solutions
https://gocarlite.com/product-category/batteries/

The old lithium Polymer (LiPo) batteries fell out of favor due to fire hazzards and explosions. Most batteries now are lithium ion but the LiPos are still sold as cheap lithium batteries, mostly from non brand vendors. So be careful and do not burn down your house. Good luck.

 

[Trail Cruiser]

Here's another danger from cheap batteries. It's better to spend quality batteries from legitimate sources than risk burning down your precious properties and family.
http://www.nbcnewyork.com/news/nati...r-Recall-Lithium-Ion-Batteries-385671691.html

 

[harryS]

To the OP, if it's an 18650 13S battery, your typical charger will put out 54.6 volts. You might want to check that and also see what your battery reads coming off the charger. It should be at 54.6 and hold the number for a while. If it's dropping down to 52 volts quickly, the battery has a problem.

Probably a slim chance, but some owners will take steps to stop charging around 50-52 volts to extend battery life. If you do this, you have to do an occasional full charge to make sure the battery gets fully balanced. Might be worth trying anyway.

With all these fire videos, if you try an extended charge, make sure there's nothing to burn down if the battery spits flames. An e-bike shop in Germany burned down last week. Yikes.

 

[1000W48V]

Your description reads just like the experience I had with my bike. After 300 recharge cycles providing reliable power for more than 5100 miles, the controller started cutting off power to the motor early into the ride while the battery still registeres adequate power levels. The diagnosis opined in this forum was "faulty cells in the battery pack" and battery failure due to age. Lithium-ion battery cells have a limited lifespan. A Battery's advertised lifespan can be misleading. While an optimal lifespan may be listed as retaining 80%+ capacity after 1000 recharge cycles, real lifespan is limited by actual use conditions.
I sent my battery out to RPE for diagnosis and rebuild. The refurbishment will upgrade the battery to 15Ah from the original 12Ah.
Rechargeable Power Energy Inc.
6585 Arville St.
Las Vegas, NV 89118-6826

Tel.: (888) 456-9410 ext 109
Cell.: (757) 303-1441
Fax: (702) 749-5906
email: [email protected]
Web: www.rechargeablepowerenergy.com

John,
Thank you for responding! I will give them a call tomorrow (Monday).....I am just now learning just how finicky lithium batteries are.
Mike

 

[1000W48V]

John,
Thank you for responding! I will give them a call tomorrow (Monday).....I am just now learning just how finicky lithium batteries are.
Mike

John, out of curiosity, how much did it cost to re-condition the battery pack?

 

[harryS]

Your typical 13S4P 48V lithium 18650 cell battery will have 52 cells. I can buy a Dolphin with top of line Samsung GA cells for $480 shipped. As an individual, best price I've seen for 52 GA cells is 6.33/cell or $330 shipped.

Gotta be tough to be a rebuilder. If they can pay about $4 for a decent cell, or $208, and the case and electronics are still good, it still could be a hard time competing with a new battery shipped for $450.

 

[bikerjohn]

John, out of curiosity, how much did it cost to re-condition the battery pack?

the 36-volt battery pack refurbishment cost was quoted at $490 delivered. I am awaiting the work to be completed right now.

 

[harryS]

Were you able to try some of the voltage checks from Mark and me? Not that easy to catch voltage sag with a digital meter on a bike that you're trying to ride at the same time.

An e-bike shop would probably just swap batteries and prove whether it's the bike or battery.,

 

[tomjasz]

Bench cleanup day.

 

[Rick Speicher]

Your work bench looks like mine when I'm in the middle of a project!

 

[Ann M.]

That looks scary, Tom! Just curious, what's a plastic coffee can doing on the bunsen burner stand??

 

[tomjasz]

I'll be sure to show the working version, sadly things piled up for a couple of months. Actually it's an annealing/soldering stand from silver smithing. A hobby long gone to the wayside. Mrs. was an art educator and guided me through some great projects. I promise no work goes on in that mess. If it did it would indeed be scary. The large battery is a 12v that powers the nickel strip welder.