I’m always considering ideas and new upgrades for crazy builds. Lately I have been looking at some of the electric mountainboard builds and wondered: well if I don’t need excessive speed but want good range, how would I do that? I may have found the answer: 24V 100ah Lead Acid Battery https://m.alibaba.com/product/60479629770/hot-sale-battery-24v-100ah-battery.html?s=p obviously I wouldn’t get his exact battery but I’m thinking if you get a CB deck and have decent motors then you could make a cross country e-board in no time. Any thoughts?
If i remember correctly li-ion has a higher power density. so while it will be cheaper for X amount of power to use Lead Acid, it will be lighter to use li-ion
Lead acid batteries are so heavy try lugging around a car battery those are like 30+ lbs
I agree with @Titoxd10001 I also don’t know what the ‘output’ curve is. So they may have an unsteady voltage output.
18650 are probably the best for range and weight but are more expensive that’s what tesla uses I believe and also electric bicycles
Ik it didn’t show up as a post but thanks to @lox897 for fixing my mistake on the original topic from 100mah to 100ah. Also @Titoxd10001 I know they weigh a lot especially compared to lithium ion but a 100ah lithium ion battery is about 1.6K in usd. Also I think weight wouldn’t be an issue if battery + rider = less than 250 lbs. obviously with a range like that you would never pick up the board, it would be an almost infinite ride
Haha. No problem. When I saw 100mah I was like wtf.
For a 6S40P battery you would need 240cells. At 4$ a pop that results in 960$. Add nickel strips and stuff for 40bucks and you’d end up with 1000$ not 1600$.
@Maxid I was looking at pre made batteries, some were going even more than 1600
And that one wasn’t even 24V
If you want a huge battery, you can buy cheaper cells with lower discharge rate, like these
A 1000Wh battery from these cells weigh 4.9 kg and able to discharge at 1000W at 1C. it would cost 411$ for 1000wh battery with 107 cells.
with lipo it would weigh 6.5 kg
If you discharge these cells to 3.6V you will get only 413Wh from 107 cells, so i think they are bad
This cell might be good 2.2 Wh/$ for 2.5Wh at 3.6V (it’s rated better)
I give up. the capacity of these battery is 1/3 the rated value if discharged to 3.6V: http://www.batteryspace.com/prod-specs/NCR18650B.pdf
Edit: space cell is discharged to 3.2V per cell. the cell above does get to 2.5Ah when discharged to 3.2V at 1C, and have fairly good cycle life when discharged to 2.5V
Looks like I got late to this party.
@anorak234 the priority with a eMTB is the maneuverability of the board and if you make it super heavy then it becomes a liability and once the this is compromise it’s not fun at all, no body wants a board just to go straight.
In my case I’m a 204 lb rider and like to keep my builds below 40 lb. in order to proper maneuver and handle the boards in any situation that comes across. Remember that once you have big pneumatics wheels and proper balance setup, you are not constrain to the pavement and smooth terrain. Now any terrain is you play ground and sometimes you want to play hard
Don’t forget I build packs specifically for mountainboards. 10s8p 25R. With bms. This latest build came with an electronics box.
Max I can fit is 12s7p or 10s8p
Looks really good. How much would it be for a pack with the ESC? Is that standard boxes or did you make them as well?
for the 12s or 10s?
The kit includes all of the electronics minus the motors and remote is optional
As someone mentioned you could get low POWER (or discharge) li-ion cheap and if you get enough in parallel you’ll have enough power and the most ENERGY and so longest range to weight. I think lead acid would be cheap per watthour but with cheap li-ion it’d be close and like 1/4 the weight. Endless-sphere someone sells some 3.5ah cells cheap. Forget which. Get 100.
I would probably go for a 10S
Can you help with a diagram with BMS for a 10s8p. I have 80 cells ready to be put together. Need a good diagram.
Alrighty I know this topic is super old, but now that it’s looking like I might have to cancel my Europe trip this summer there is a very real possibility that I could find myself trying to make a cross-country trip with my hybrid MTB and trailer. I’ve allocated myself about $1,000 for all battery upgrades AND spare parts/camping gear (i.e. spare FOCbox, tubes, tires, small stove, etc.) I am now looking at large batteries again that won’t break the bank and don’t need high discharge. I am fully aware of the weight, but other than that does anyone see issues with stowing some 100ah lead acids in the trailer?
Tipping over may be a concern? I would use some mtb trucks and get that thing as low to the ground as possible and extended width
Maybe a rear mounted hanger that allows the trailer to sit below the top of the trucks