Intro

[Irish-e-chris]

Hi there newbie from Ireland. I'm in the process to built my first e-bike based on an oldish Giant MTB I got for this. Idea is to replace my car completly seeing that I only travel locally lately and work mostly from home.
I ordered a CSC MTX39 kit with 1500W and LCD8H as I am a fairly heavy lad and ive in a hilly area. Battery is a 14S6P with a 40A BMS controler is the KT with 18mosfets
I plan to install this with PAS and "limited" speed (while on public road to stay somewhat legal and upgraded the brakes to cable/hydro disks 180mm front 160 rear. Bits should be here in the next few days will update the psot when parts are here and bike is built

 

[Benjahmin]

Pity you didn't ask here first.
A 1500w motor is almost bound to be a direct drive (rather than a geared hub) and will be good at high speed on the flat but pretty gutless and battery munching on hills.
What's the max current on the controller? The battery will need to be able to deliver that plus around 50% to not be quickly damaged.
Many people get caught up in the big numbers but, actually, a 250w rated hub motor with a 17A controller and battery to suit, makes a fine commuter.

 

[Nealh]

Chris will likely be ok with hills with that kit as he has opted for high current (looks like he has done his homework), which those kits really need to be useful. As long as the battery is capable of 40a continuous or more it should deliver the power but as mentioned range won't be mega, depends on the battery capacity.

A lot of people make the mistake of buying these kits with an inefficient 20a capable system which just doesn't cut it and a mediocre battery. The devil is all in the detail of the battery specs to deliver the power for higher current draw.

 

[Irish-e-chris]

Pity you didn't ask here first.
A 1500w motor is almost bound to be a direct drive (rather than a geared hub) and will be good at high speed on the flat but pretty gutless and battery munching on hills.
What's the max current on the controller?

Yes it's a direct drive KT controler with regen. Curent is 45A
Batt etc see replay to Nealh

 

[Irish-e-chris]

Chris will likely be ok with hills with that kit as he has opted for high current (looks like he has done his homework), which those kits really need to be useful. As long as the battery is capable of 40a continuous or more it should deliver the power but as mentioned range won't be mega, depends on the battery capacity.

Yeah I've read stuff for a few weeks before I purchased and noticed the pitfalls of batteries and controllers being a bottleneck. Watched a few Youtube channels too like Andy K's.
Battery is custom built rated for 1500/2000W with a BMS 40A constant and 100A max (1sec) rating controller is 45A dual mode and I might change that at some stage to a Sabvoton or something. Pretty sure that will do as the hills aren't that lethal, and I hope to loose another few pounds (88kg now)

 

[vfr400]

The battery looks like the weak point to me. It'll probably work, but it won't last very long at that sort of current. It's going to cook itself. Heat goes up with the square of the current so at 40A, it'll make 4 times as much heat as at 20A, and they get quite warm at 20A.

 

[Irish-e-chris]

I know that 18650's are reaching their limit at that current. However a lot depends on the quality of cells used as the difference in what they deliver is as high as 50%. At 40A it should be OK realistically how often and how long do you go at full belt?.... I know from Andy Kirby that you really need to push those batteries past 50A to kill them early.... I doubt I do that as I am not planning on crossing the alps or do a trip to the Scottish Highlands any time soon.