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Freelander X7 E-scooter Modification for Hill Climbing

 Hi,


I bought an e-scooter recently with the following specifications:


Brushless permanent magnet DC motor

Power: 300W

Rated speed: 2400 r/min

Rated Voltage: 18.5 V


Li-Ion battery

Capacity: 10 Ah

Voltage: 18.5 V


Brake: Power brake, mechanic disc brake

Max speed: 15.5 mph

Max load: 176 lbs

Scooter weight: 18.04 lbs

Grade ability: 15 degree slope


The e-scooter seems to struggle to climb small hills (with 165 lbs load), it gets stuck, I would appreciate any suggestions to modify the e-scooter so it is able to climb hills.

Which is the approximated minimum motor power required for hill climbing? Any brushless DC motors recommended? Which components would be required in the modification?

Could you please give me a few options and quotation.

Many thanks.




I took out the motor and had a look at the sprocket. It looks to have an inside diameter of 8mm x 7mm. I am guessing ID means inside diameter?

I am thinking the 9 tooth motor sprocket combined with the 65 tooth wheel sprocket might provide a good balance between top speed and torque.



 



.. sorry pictures are huge but I don't know how to make them smaller

Yes when referring to measurements ID does stand for inside diameter, and the ID of the sprocket in your photos definitely looks to be 8mm x 7 mm.


Our 9 tooth sprocket for #25 chain with 8mm x 7mm ID has a thinner collar than the sprocket in your photos however we do sell washers that could be used to make the sprocket thicker if necessary. Here is a link to the page that we sell the SPR=NW8 nut and washer on: 

https://cart.electricscooterparts.com/nut-and-washer-for-8mm-left-hand-thread-motor-shafts

Okay thanks. I have ordered the 9 tooth motor sprocket and the washer which you linked above.

Will try this first on the hills in my area and let you know how it goes. If a higher gear ratio is still needed then I may try the additional 65 tooth wheel sprocket.

 

Hi Ravi, thank you for your order. I think that you might need more than one washer to make up the difference in width between the old 10 tooth sprocket and the new 9 tooth sprocket, so I added 5 extra washers onto your order. There is no charge for these extra washers - I am including them with your order for free.

I am curious how the sprocket attaches to the motor shaft. It looks like maybe there is a c-clip holding the sprocket onto the shaft?

 Oh thanks for that. There is quite a difference in width so I might need those extra washers. 


Yes, the sprocket is held onto the motor shaft with a c-clip. There is also some kind of thin, flexing washer padding vibration between the c-clip and sprocket.






Thanks for attaching those photos Ravi. That is a very unique way for the sprocket to be attached to the motor, at least in the realm of electric scooters. I see how that spring washer presses the sprocket into place and puts tension on both the sprocket and c-clip. From what I can see the Freelander X7 scooter is made completely differently from most other scooters - it looks like it was designed from scratch. That is refreshing to see because these days most electric scooters are made from the same parts that are made in the same factories, and they all are pretty much the same.

No problem, I'm happy to share more photos to anyone who is interested.

Yes, it seems the scooter has quite a unique design which I like and well thought out. It's well designed, but unfortunately they have used cheap materials to make the parts, so because of this, it does seem to need a fair bit of maintenance - parts often needing to be replaced/repaired, so I probably would not recommend this scooter to it anyone who is not interested in DIY.


Actually I have ran into a problem - a few days ago I was riding it on a hot day when the power cut off and it wouldn't start again. When I tried to charge it, the light on the charger just flickered from green to orange. I took out the battery and found that one of the cells had leaked/corroded (picture attached).


I don't know if I should try to replace the whole battery or just the dead cell only. I'm guessing it would be easier to replace the dead cell if a correct replacement can be found. The battery seems to be made up of 25x 18650 lithium batteries (65mm x 18mm size). I'm pretty sure they are the 1600mAh type (according to my calculations). 


Llafra, may I ask where you got your battery replacement?


I know this battery issue is off the topic of hill climbing, but I am not sure what to do from here.. I have received the sprocket and I'm am keen to try out this mod, but unfortunately I can't go any further until this battery issue is fixed. Any suggestions are appreciated.




 

Replacing one of the cells might work, however if it was my scooter I would worry that the other cells in the battery pack might have also been damaged from overheating. From the photo showing the melted and burned through blue plastic heat shrink tube it looks like there was a lot of heat involved in the failure.


As far as replacement batteries go I would use name brand cells such as those made by Samsung or Sanyo. They  have less problems and last longer than the generic no-name brand lithium ion batteries, and they usually do not cost that much more either.


Although it could have been caused by a manufacturing defect, I think that the battery pack failure was most likely caused by too much of a load applied to the battery pack. These type of small lithium ion batteries can not handle outputting too may Amps or else they will overheat. Lowering the gear ratio like you are planning to do will lower the power load on the motor which will in effect lower the Amp load on the battery pack and it will run cooler.

Thanks for the quick reply.
Yes, I was going up a big hill when the it happened so it would definitely make sense that the failure was due too many amps being drawn from the batteries in a short amount of time, which led to overheating.

It looks like the battery closest to the corner in the photo is gone, but the other batteries still look okay. I would like to try replacing the dead battery cell with a Samsung 18650-15M which I found in a local store. I hope it is compatible with the installed batteries (the batteries currently being used have the model number "INR18650P" written on them).

 

I hope not to have to replace the whole battery pack (looks like this would be expansive), so I will try replacing the dead cell first.


Cheers

Thanks for the update Ravi. That sounds like a good idea. Please let us know how it works out.

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