Monday 27 June 2016

Ghetto ebike Build

So, I decided to build an ebike. While I wait for other parts to arrive, here are my current plans.
I have two Lipo batteries which I plan on wiring in series to make a 48v battery. They are Multistar 16000mah 6s Lithium Polymer packs.

These packs weigh 1.978kg each, their dimensions are: 18cm x 7.5cm x 7.3cm which is about the same volume as a bike drink bottle.

Interestingly, when you buy such large quantities of lithium packs here in the UK, the packaging comes with it's own materials identifier label, you also get a phone call from customer services to ask you about your delivery which is interesting. I have never had that before. Always have a cup of tea close by

I plan to mount these two lipo packs to a bike frame, close to the drinks bottle mount positions. I have some super-strong PETG filament to print and design some kind of mount clamp support thing, i'm sure it will be suitable

I chose to use these packs over Li-ion packs for a number of reasons. The price is low as they are currently on offer, I already have fast charging for these packs (I have Turnigy Reaktor 300w charging), I have trust in the specification of these packs - I am still unsure about buying 18650 cells from the internet and trusting their reliability. I have cut open many 18650 cells in the past and have noticed so many counterfeit cells - they are usually containing much smaller lithium cells inside and filled with a white powder to fill the tubing. Here's a video showing the white powder inside, some more links here here and here. I must note that I have some good 18650 cells from Panasonic, they are 3400mah panasonic ncr18650b cells which I use in my torches, they are wonderful, the real-deal but costly. Once you experience fake 18650 cells you are hurt. Why do they do this? It looks like a lot of work to make those fake cells, I wonder who's doing it?

I also like the capacity to price of these packs. 16ah capacity. The most common Li-ion packs appear to be around 8-11ah and their cost is ranging from £200-£600 (or £400-£1000 after all this post Brexit shit completes its so called meltdown :) lol fear!!! Be afraid!!! hahaha

I know that the Li-ion cells have a greater number of charge cycles (over 2000+ supposedly), the Lipo packs are rated at 500 charge cycles. In real-world, this is more subjective based on full-charge or part-charging, discharge rates etc. For the price, I am happy to use lipo. I am not interested in spot-welding my own 18650 Li-ion pack or making a BMS wiring system for them, I like the simplicity of these 6s packs to use with my charging station

I also have some nice XT90 connectors to link the packs

The size as you can see is quite larger than XT60 connectors. I also have 10AWG wire to solder the harness adapter.

The bike I am using for this experiment, I pulled from a skip. It is a Carrera mountain bike which I will modify, the frame is good, the wheels are fine. So the bike was free. Free is good.

So while I wait for the motor to arrive here are some more photos of the lipo packs. I will update more on the build soon, it should be a fast build.


Tim Kent said...

Looks like an awesome project. Would you consider sharing the battery mount models on GitHub or the likes? I've already got a Dolphin pack with 18650 cells, but I'm following with interest!

DalyBulge said...

It will be considered :)