Did I destroy my battery?

[Keith]

2 minutes ago, Esper said:

I did see a battery with a tab on it for sale online. I thought they were soldered on. Is there a difference between the spot weld and the solder? other than one is bad and one is better.

18650 cells with tabs have the tabs spot welded onto the cell the tab can then be soldered as required (but with care) Spot welding is near enough instantaneous so virtually no heating of the battery occurs. Soldering needs around 650 degrees Fahrenheit (340C) applied long enough to melt the solder into the cell case. That heat will transfer through and possibly start to melt the insulation inside the cell.

[Esper]

2 minutes ago, esaj said:

@Keith beat me to it... batteries with solder joints in a vehicle that takes a lot of jolts and shocks and vibrates all the time might not be a good idea. Spot welding is the way to go. Also, overheating the cells by accident may cause them to light on fire or explode.

 

If you're unsure of the procedure or whether you can make strong enough joints with a soldering iron, your best bet would be to order a new battery from someone who can do it, like 1RadWerkstatt in Germany.

The BMSs used in the wheels need separate charge- and discharge-side, if they use the same wiring for both, there are certain dangerous protections, like overvoltage protection, which can cut power when braking or going downhill on a full battery.

The Great Battery Wizard has spoken!
I agree with him in that it would be a good idea to buy one from someone that makes battery pack. If you do it yourself though, it provides a great learning experience and you can then apply this knowledge to many more things other than just an EUC.

[jaytee]

8 minutes ago, esaj said:

@Keith beat me to it... batteries with solder joints in a vehicle that takes a lot of jolts and shocks and vibrates all the time might not be a good idea. Spot welding is the way to go. Also, overheating the cells by accident may cause them to light on fire or explode.

 

If you're unsure of the procedure or whether you can make strong enough joints with a soldering iron, your best bet would be to order a new battery from someone who can do it, like 1RadWerkstatt in Germany. They can built the battery to measure with the correct cells and BMS, and using professional grade spot-welding equipment. They likely already know the measurements & parts for most common brand-name models.

 The BMSs used in the wheels need separate charge- and discharge-side, if they use the same wiring for both, there are certain dangerous protections, like overvoltage protection, which can cut power when braking or going downhill on a full battery. Also too "sensitive" overcurrent- or overdischarge-protection in the BMS can cut power during acceleration / takeoff, even if the BMS otherwise has separate discharge- and charge-side protections.

Thanks for weighing in esaj. I'll definitely check out 1RadWekstatt

On a seperate note: I think this might be the same or *very* similar to the battery back in the Luffy.

What do ya'll think of these specs? Looks it may have the separate charge/discharge loops that esaj said should be included. 

https://www.aliexpress.com/item/Original-18650-22PM-cells-16S1P-for-60V-2200mah-lithium-battery-pack-2-2ah-for-electric-skateboard/32812290855.html

Original 18650-22PM cells 16S1P for 60V 2200mah lithium battery pack 2.2ah for electric skateboard unicycels scooter wheelchair  free shipping

Specification:

• Product description: lithium ion battery pac
• Nominal capacity: 2200mAh
• Charging ways: Constant Voltage constant Current
• Size: about 47*68*150mm
• Weight: 0.87Kg around
• Composed Type :Charging panel(16S1P)
• Components: Big Brand Dynamic 18650 Li-ion cells
• Application:  Electric Unicycles,e-bicycles,e-scooters
• Overdischarge protection: YES
• Overcurrent Protection: YES
• Discharge Cutoff Voltage (V)  67.2v
• Charge Cutoff Voltage (V) 43.2v
• Rated Discharge Current (A)  10A
• Instantaneous Maximum Discharge Current (A)  30A
• Standard Currents: 2.2A
• Max.Continuous Discharge Currents: 20A
• Max charging current: 5A
• Approved: CE,CCC
• Cycle life: More than 1000 times
• Input Voltage: 67.2V,CC/CV
• Battery have overcharge, over discharge, over current, short circuit, charge equalization of automatic identification and protection circuit
• IF you need other discharge plug ,please contact us ,or leave a message.

Packing list:
1. 60V 2200mAh power Lithium Battery(with Built-in high quality BMS board)

 

 

[jaytee]

10 minutes ago, Esper said:

The Great Battery Wizard has spoken!
I agree with him in that it would be a good idea to buy one from someone that makes battery pack. If you do it yourself though, it provides a great learning experience and you can then apply this knowledge to many more things other than just an EUC.

For sure.. that tutorial was quite informative. Though I think perhaps spot welding is above my pay grade for now ;). So seems maybe some  options are to find a suitable pre-configured pack or work with a maker like 1RadWekstatt to build to spec.

[esaj]

6 minutes ago, jaytee said:

Thanks for weighing in esaj. I'll definitely check out 1RadWekstatt

On a seperate note: I think this might be the same or *very* similar to the battery back in the Luffy.

What do ya'll think of these specs? Looks it may have the separate charge/discharge loops that esaj said should be included. 

https://www.aliexpress.com/item/Original-18650-22PM-cells-16S1P-for-60V-2200mah-lithium-battery-pack-2-2ah-for-electric-skateboard/32812290855.html

Original 18650-22PM cells 16S1P for 60V 2200mah lithium battery pack 2.2ah for electric skateboard unicycels scooter wheelchair  free shipping

Specification:

• Product description: lithium ion battery pac
• Nominal capacity: 2200mAh
• Charging ways: Constant Voltage constant Current
• Size: about 47*68*150mm
• Weight: 0.87Kg around
• Composed Type :Charging panel(16S1P)
• Components: Big Brand Dynamic 18650 Li-ion cells
• Application:  Electric Unicycles,e-bicycles,e-scooters
• Overdischarge protection: YES
• Overcurrent Protection: YES
• Discharge Cutoff Voltage (V)  67.2v
• Charge Cutoff Voltage (V) 43.2v
•  Rated Discharge Current (A)  10A
•  Instantaneous Maximum Discharge Current (A)  30A
• Standard Currents: 2.2A
• Max.Continuous Discharge Currents: 20A
• Max charging current: 5A
• Approved: CE,CCC
• Cycle life: More than 1000 times
• Input Voltage: 67.2V,CC/CV
• Battery have overcharge, over discharge, over current, short circuit, charge equalization of automatic identification and protection circuit
• IF you need other discharge plug ,please contact us ,or leave a message.

Packing list:
1. 60V 2200mAh power Lithium Battery(with Built-in high quality BMS board)

 

 

It's a 132Wh pack, which is pretty much the smallest capacity 16S1P you can get, I don't know how large battery Luffy normally has. They don't state the actual cell model, which is a bit suspicious, maybe. Could be just fine though, maybe they just use different brand-name cells, whatever they might get at cheapest at the moment, but in the worst case they use some unknown Chinese cells which can be something like from "ok" to "total crap" quality wise. 43.2v undervoltage cut-off should be good enough (2.7V / cell), don't know how much power Luffy can draw, so 30A maximum instantaneous might be a bit low (about 1.8kW max)? If it's too low, the pack will cut power during fast acceleration / hill climbing / hitting a pothole or such condition, which requires high current in short burst. 20A continuous is about 1.2kW.

If you decide to order that pack, make sure the battery pack can fit in the shell and that the connectors are the same as with your wheel. Likely they can build it to use whatever connectors you have, just make sure beforehand, so you don't have to start changing them yourself. There's a way to bypass the discharge-side protections, but it's not for faint of heart, and of course then you will have NO PROTECTIONS WHATSOEVER on the discharge-side. Definitely never short-circuit a "shunted" (discharge-side protections bypassed) pack  

[jaytee]

1 minute ago, esaj said:

It's a 132Wh pack, which is pretty much the smallest capacity 16S1P you can get, I don't know how large battery Luffy normally has. They don't state the actual cell model, which is a bit suspicious, maybe. Could be just fine though, maybe they just use different brand-name cells, whatever they might get at cheapest at the moment, but in the worst case they use some unknown Chinese cells which can be something like from "ok" to "total crap" quality wise. 43.2v undervoltage cut-off should be good enough (2.7V / cell), don't know how much power Luffy can draw, so 30A maximum instantaneous might be a bit low (about 1.8kW max)? If it's too low, the pack will cut power during fast acceleration / hill climbing / hitting a pothole or such condition, which requires high current in short burst. 20A continuous is about 1.2kW.

If you decide to order that pack, make sure the battery pack can fit in the shell and that the connectors are the same as with your wheel. Likely they can build it to use whatever connectors you have, just make sure beforehand, so you don't have to start changing them yourself. There's a way to bypass the discharge-side protections, but it's not for faint of heart, and of course then you will have NO PROTECTIONS WHATSOEVER on the discharge-side. Definitely never short-circuit a "shunted" (discharge-side protections bypassed) pack  

The luffy comes in 130, 170 and 200wh sizes. I personally have the 200wh size. The screenshot of the video I posted earlier was a 130wh battery. Thats the one that looked about the same. Blue, wrapping, dimensions and connectors.

It is weird that they dont mention the brand... but I think this is common. One reason could be manufacturer prohibit it. Licensing / legal and all that sort of stuff. 

Will definitely take apart the luffy and have a look at the pack first before going forward.

Whats iteresting in the difference in specs. http://www.wheelzworld.com/DATA/images/specs/WheelzWorld LUFFY Gotway En.pdf

You can see the 130 and 170 wh are 30a but my version, the 200wh is only 10a. Seems like a tradeoff now that I think about it... heh

[jaytee]

[esaj]

9 minutes ago, jaytee said:

The luffy comes in 130, 170 and 200wh sizes. I personally have the 200wh size. The screenshot of the video I posted earlier was a 130wh battery. Thats the one that looked about the same. Blue, wrapping, dimensions and connectors.

Yeah, the wrapping color doesn't really mean anything... blue just seems most common.

Quote

It is weird that they dont mention the brand... but I think this is common. One reason could be manufacturer prohibit it. Licensing / legal and all that sort of stuff. 

Will definitely take apart the luffy and have a look at the pack first before going forward.

Whats iteresting in the difference in specs. http://www.wheelzworld.com/DATA/images/specs/WheelzWorld LUFFY Gotway En.pdf

You can see the 130 and 170 wh are 30a but my version, the 200wh is only 10a. Seems like a tradeoff now that I think about it... heh

Never knew Gotway released the battery cell information in the datasheets, that's nice. The maximum current for the cells is reported as the maximum continuous, any cell can give a huge short burts of current (like 100A), but can't take it for long without overheating. There's a tradeoff between high capacity and maximum current, usually the cells with higher capacity have lower maximum current (higher internal resistance, I'd guess). If the wheel works just fine with 10A max cells and single pack, then pretty much any brand-name cell should be fine. If going from 200Wh -> 132Wh, you'll be almost halving the battery capacity though.

Based on this, I'd take an "educated guess" (but not promise anything ), that the Aliexpress-pack could work just fine. Still, there's always the risk that the cells aren't really good ones (brand-name cells) and/or that the protections trigger too easily...