• From: Plymouth, MA
  • Registered: 2013-06-07
  • Posts: 780

Topic: Electric skateboard repair (?battery) "for dummies"

My teenage son wanted an electric skateboard, but did not have enough money to buy a new one.  So he did what his dumb dad does, and buys one used, and decides he will repair it, and make it AWESOME. And his plans are taking a similar path to his dads, but unfortunately he is getting  super frustrated and discouraged. So I decided to help him out, but I'm not getting much further....
Anyone know anything about electric skateboard repair and batteries? 

He got the skateboard with a rechargeable battery that was basically dead, but actually would work for a minute or less.  So it seems the motor in the wheels and the computer are functional, and he just needs a new battery.
So he bought one (non returnable, poor kid), plugged it in, but it does almost nothing.

I compared the 2 batteries, and they look similar, but are different
Old battery: 36V==115Wh 3200mAh (HB3200 Li-poly battery pack)
Came with skateboard "Landwheel", some chinese company, that I believe is out of business

New battery Model 6s3p from MBoards some internet DIY electric skateboard repair web site
Lithium-ion battery pack
21.6V, 9000mAh
194.4Wh
Cells: Samsung 30q

So I guess the problem is that the 2 batteries are different?
Any ideas how to make this work, and make it AWESOME?  I was thinking of just mounting my spare car battery on the skateboard and hooking that up....but I suspect that would probably not work....

MarioKart Driving School: 1987 Honda Prelude Si (Opus #28) 
Loudon, NH 2014 - Millville, NJ, Lightening 2019 (RIP)
New and improved: 1987 Honda Prelude Si (Opus #11) Pittsburgh, PA 2021 - ??
and finally won something, Class C Win: Loudon, NH 2022
  • From: Sharon, MA
  • Registered: 2015-12-28
  • Posts: 32

Re: Electric skateboard repair (?battery) "for dummies"

Definitely do not use the original charger, you will need to charge the 30Q's with something else.  If they have overvoltage protection in the pack he bought then it might be blocking the charger from damaging them so they are not going to charge. That is waaay overvoltage for each cell if the charger is charging them in series. post a link to the pack he baught.

Possibility: Also, the scooter itself might have a undervoltage protection built in, which should be 3V per cell for LiPo cells. So that cutoff might be 30V and the new pack is way below that.  Assuming they were 3.6-3.7V nominal cells, so 10*3V.  The 30Q can be safely discharged to 2.7V.  I would see if the site he got the pack from has a charger.

The other option is adding some 30Q cells to bump the voltage up on the new pack.  You can get 30Q's from US sellers for $5 each.

I would wire two car batteries in series to get 24V and see if the scooter turns on and spins on a table.  Then you know the new pack voltage will be OK for the scooter.  But it will be slower.  If that worked then I think it's just a matter of getting the right charger for the new pack.  My chargers only do individual cells, not packs...I am sure the new pack is welded tabs.

  • From: Elverson, PA
  • Registered: 2017-08-15
  • Posts: 1,118

Re: Electric skateboard repair (?battery) "for dummies"

3 x 12V lawn tractor batteries = 36V
2 x 18V Makita power tool batteries = 36V

...

I'm visualizing a teensy-tiny miniature HarborFreight trailer replica carrying the batteries, attached to the back of the skateboard with a 3-axis tow bar  ...

I clearly have too much time on my hands.

  • From: Plymouth, MA
  • Registered: 2013-06-07
  • Posts: 780

Re: Electric skateboard repair (?battery) "for dummies"

Love it! Harbor Freight -here I come!
Maybe a Judge Mobile in the making...???

Skate board and new battery each came with its own charger, and both batteries charge...
I checked with volt meter

This is what he purchased
https://www.mboards.co/collections/batt … y-solution

(I love working with electricity, but I still struggle with voltage, watts, resistance, current, Ohm's law, joules, AC, DC, capacitors, relay switches, etc.. ....and I know what 220 feels like....)

Not sure I follow: "Assuming they were 3.6-3.7V nominal cells, so 10*3V.  The 30Q can be safely discharged to 2.7V. "??

And how would you make this work: "The other option is adding some 30Q cells to bump the voltage up on the new pack.  You can get 30Q's from US sellers for $5 each."? How would you wire them?

And how would you wire this:" I would wire two car batteries in series to get 24V and see if the scooter turns on and spins on a table."---

Is this just a matter of getting enough batteries to equal at least the original 36V? and wiring the + and -??

MarioKart Driving School: 1987 Honda Prelude Si (Opus #28) 
Loudon, NH 2014 - Millville, NJ, Lightening 2019 (RIP)
New and improved: 1987 Honda Prelude Si (Opus #11) Pittsburgh, PA 2021 - ??
and finally won something, Class C Win: Loudon, NH 2022
  • From: Elverson, PA
  • Registered: 2017-08-15
  • Posts: 1,118

Re: Electric skateboard repair (?battery) "for dummies"

MZAVARIN wrote:

Love it! Harbor Freight -here I come!
Maybe a Judge Mobile in the making...???[snip]

good idea!

MZAVARIN wrote:

[snip]
(I love working with electricity, but I still struggle with voltage, watts, resistance, current, Ohm's law, joules, AC, DC, capacitors, relay switches, etc.. ....and I know what 220 feels like....)[snip]

this ^ is an example of impedence ;-)

MZAVARIN wrote:

[snip]
And how would you wire this:"

RedBoss wrote:

[snip]I would wire two car batteries in series to get 24V and see if the scooter turns on and spins on a table."---[snip]

This ^ is a good suggestion from RedBoss, and I defer to his apparently detailed knowledge in this tech. I would still want to match the voltage to the device, but the idea of testing on a table is compelling.
To answer in detail:
     a: 2 x 12V in parallel gives you twice the power capacity, but still 12V; for example: many diesel pickups run with two 12V batteries in parallel - that is, the positive terminals of each battery are connected.

Let's see if I can get diagrams work on the 'net (these are for 3 batteries):

HOT>|(+)| = |(+)| = |(+)|
          |12|    |12 |    |12|   = still 12V
          |(-)| = |( -) | = | (-)|<GND

[ "=" >  same polarity connections of adjacent batteries]

     b: 2 x 12V in series gives you 24V, as you step up 12V through the first battery, and another 12V through the second; for one example, some will power RV 12V house power by connecting 2 x 6V deep cycle (like golf car) batteries to get long draw-down 12V power for boondocking.
I'll still recommend 3 batteries to get 36V. In this case, face identical batteries the same way, right next to each other in a rectangle [if the batteries are not identical, pay _especially_ close attention to terminal polarity]. The diagonally opposite corner terminals should be one positive and one negative. These would be your connections to what you're powering. [If the ones you picked are the wrong pole for the closest cable, pick the other terminals. You can also rotate the rectangle of batteries, and, you can rotate the batteries within the rectangle.] The middle battery's terminals are connected to the _opposite_ pole of the next battery.

HOT>|(+)|   |(+) |   |(+)|
          |12| / |12 | / |12|   = 36V
          |(-) |   |( -) |   | (-)|<GND

[/ = negative to positive connection of adjacent batteries]

MZAVARIN wrote:

[snip]
Is this just a matter of getting enough batteries to equal at least the original 36V? and wiring the + and -??

For me, yes; I was just thinking of a less expensive way to power the 'board with the voltage it expects. Though, if you have enough car batteries, then you wouldn't need lawn tractor batteries - I was thinking of them as lower weight on the power unit.

  • Mr.Yuck
  • Mr.Yuck
  • Lemons Staff Stalker
  • Offline
  • From: Brookeville, Md.
  • Registered: 2013-12-09
  • Posts: 1,012

Re: Electric skateboard repair (?battery) "for dummies"

My son had an electric scooter, same issue after a year or so the battery died. I just went on ebay and ordered another one, had no issues using the original charger. Sometimes the batteries will come with a charger, but you will pay more.

"get up and get your grandma outta here"
  • From: Raleigh, NC
  • Registered: 2020-01-25
  • Posts: 325

Re: Electric skateboard repair (?battery) "for dummies"

Mr yuck has the answer.
Buy the correct batteries.
Rewire it back to stock

Former Captain
1996 Crown Vic. #55
Team Racing Cosmo
  • From: Plymouth, MA
  • Registered: 2013-06-07
  • Posts: 780

Re: Electric skateboard repair (?battery) "for dummies"

Company is out of business, so correct/original battery is not available
The replacement battery came with a charger and charges appropriately to voltage....

I think I could probably come up with a Lemony wiring solution to all this ....based on what I am learning and trying to remember from my physics classes....(although, as I recall, I ended up in "C" class.....in my physics class....)

We'll see what happens this week when I have a day off....

MarioKart Driving School: 1987 Honda Prelude Si (Opus #28) 
Loudon, NH 2014 - Millville, NJ, Lightening 2019 (RIP)
New and improved: 1987 Honda Prelude Si (Opus #11) Pittsburgh, PA 2021 - ??
and finally won something, Class C Win: Loudon, NH 2022
  • From: WPB Fl.
  • Registered: 2010-10-27
  • Posts: 1,571

Re: Electric skateboard repair (?battery) "for dummies"

MZAVARIN wrote:

Company is out of business, so correct/original battery is not available
The replacement battery came with a charger and charges appropriately to voltage....

I think I could probably come up with a Lemony wiring solution to all this ....based on what I am learning and trying to remember from my physics classes....(although, as I recall, I ended up in "C" class.....in my physics class....)

We'll see what happens this week when I have a day off....

Its not just the battery, the controller likely has a low volt point that cuts things off, 22v even properly charged, will likely not get the interest of the controller looking for 36v

Homestead Chump 5th-Sebring 6th-PBIR Lemons 9th - Charlotte Chump  CrashnBurn 9th
Sebring 6th again -NOLA Chump 1st -PBIR Chump Trans Fail 16th
Daytona 11th - Sebring 6th - Atlanta Motor Speedway 2nd - Road Atlanta Trans Fail 61st-Road Atlanta 5th
Daytona 13th - Charlotte 9th - Sebring 2nd-Charlotte 25th broken brakes - Road Atlanta 14 10th-Daytona 14  58th- Humid TT 19th Judges' Choice!
  • From: Plymouth, MA
  • Registered: 2013-06-07
  • Posts: 780

Re: Electric skateboard repair (?battery) "for dummies"

interesting...I wound never have thought the controller would be involved....
Maybe if I try to hook up the new battery :
Lithium-ion battery pack
21.6V, 9000mAh
194.4Wh
Cells: Samsung 30q

to my Prelude battery (since she won't need it any time soon....!) in series....
only for testing purposes?
So 21.6 V + 12 V car battery = 33.6 V close enough to 36V stock battery enough?
OK to hook up in series the car lead car battery with the Lithium battery?

MarioKart Driving School: 1987 Honda Prelude Si (Opus #28) 
Loudon, NH 2014 - Millville, NJ, Lightening 2019 (RIP)
New and improved: 1987 Honda Prelude Si (Opus #11) Pittsburgh, PA 2021 - ??
and finally won something, Class C Win: Loudon, NH 2022
  • From: WPB Fl.
  • Registered: 2010-10-27
  • Posts: 1,571

Re: Electric skateboard repair (?battery) "for dummies"

From what I know , yes to all.

Homestead Chump 5th-Sebring 6th-PBIR Lemons 9th - Charlotte Chump  CrashnBurn 9th
Sebring 6th again -NOLA Chump 1st -PBIR Chump Trans Fail 16th
Daytona 11th - Sebring 6th - Atlanta Motor Speedway 2nd - Road Atlanta Trans Fail 61st-Road Atlanta 5th
Daytona 13th - Charlotte 9th - Sebring 2nd-Charlotte 25th broken brakes - Road Atlanta 14 10th-Daytona 14  58th- Humid TT 19th Judges' Choice!
  • From: Plymouth, MA
  • Registered: 2013-06-07
  • Posts: 780

Re: Electric skateboard repair (?battery) "for dummies"

Thanks to all contributors!
So I sat in the bedroom, wiring stuff, in parallel, in series, cordless tools, car battery,,skateboard battery, etc.

https://uniim1.shutterfly.com/ng/services/mediarender/THISLIFE/003008623257/media/1682291303907625/medium/1604358073/enhance

And got it running!

But not practical, so I ordered a rechargeable battery on ebay, China via Chicago....but then they said they had none in stock (and refunded me immediately), but then I found some guy in Nebraska that makes them and sells them on Etsy...so I ordered..and it got stuck in some USPS warehouse in Iowa for 2 weeks, but eventually came in

https://uniim1.shutterfly.com/ng/services/mediarender/THISLIFE/003008623257/media/1682291318292569/small/1604358073/enhance

and we wired it, and my son got into in, and wired it, and mounted it, and it Works!

https://uniim1.shutterfly.com/ng/services/mediarender/THISLIFE/003008623257/media/1682291324747781/medium/1604358071/enhance

https://uniim1.shutterfly.com/ng/services/mediarender/THISLIFE/003008623257/media/1682291315310734/medium/1604358072/enhance

Thanks again to all
(now hopefully I could figure out how to swap the wiring harnesses on my 2 cars, making sure the flippy lights work....besides everything else.)

MarioKart Driving School: 1987 Honda Prelude Si (Opus #28) 
Loudon, NH 2014 - Millville, NJ, Lightening 2019 (RIP)
New and improved: 1987 Honda Prelude Si (Opus #11) Pittsburgh, PA 2021 - ??
and finally won something, Class C Win: Loudon, NH 2022