2000wh battery bag

[cwah]

hello all,

I've been banging my head for a long long time to get a decent amount of capacity on my bike.

I've purchased 200 NCR18650PF, each cell has about 9-10wh capacity usable. I have cells bracket, but they take lots of space, I tried few configuration to see which one would work best:

Although trapeze shape may seem to save space, in practice it doesn't because you'll never leave your battery in a trapeze holder or bracket.

Then I protected each serie with tape to protect against short:

I tapped the whole to avoid wires chafing or even the nickel strip may touch other things:

Then used a long jubilee clamp to secure the cells.

And created my bag out of heavy duty tarpaulin:

The bag can easily be added or removed, and I can pedal

I bought a python lock to secure the bag and lock it against thieves:
http://www.amazon.co.uk/Master-Lock-8420EURD-Python-Positions/dp/B0035RQZ90/ref=cm_cr_pr_sims_t

Now, I just have to make it waterproof where there are fabric against each other and maybe even add a pocket to the bag so that I can put my laptop in and use it as work bag!!!

 

[fesanand]

Why not pelicase?
Waterproof and with the correct padlock is also anti theft. I'm currently using a Pelicase 1300 for 126cells + controller. Might be too compromised for your 200 cells (15cm depth is not enough for 2 blocks of 100 cells of 18650), but if you get the pelican im2075 i'm sure will fit. You also need double crown forks ( mine cost me 80gbp in ebay) and specific clamps for their stanchions (I can provide link of a uk website where I got mines).

My last build:
http://endless-sphere.com/forums/viewtopic.php?f=6&t=67159

Cheers.

 

[cwah]

I have thought of using a pelicase.... or other hardboxes but...
- It's never exactly the right size, so there are either too much space or not enough.
- There aren't any quick release available for the box (except for the moped top box but they are not the right size at all and not that safe)
- Putting in on the front requires special double crown fork, it affects the handling too as quite high and steering as the battery moves with the handlebar. On the frame it has much less impact.
- I can easily move it onto any bike with this frame setup

For all these reason, a custom bag/box would be the most appropriate. I decided to get a bag because makes it much smaller and lighter than a box would be


Here's the bike protected with the python lock:

 

[MadRhino]

Can you please tell me what is the weight of 2000 wh 18650 cells, fully assembled, less the case or bag.

 

[cwah]

I took my balance and put it on weight all included (with bag) and...

I couldn't believe my eyes! 10.26kg all included!

If I remove the bag + bolt I think I should be able to shave 300-600g. Let say 500g. So a pack of 9.5kg!!!

So very nice "lightweight" crazy capacity battery!

A new era has started with 9.5kg for 2000WH


I almost want to double the capacity and put 400 cells... it would be heavier but bearable :lol:

 

[MadRhino]

Hey, makes me wanna try.
Charge and output C rate ?

 

[cwah]

If I remember correctly, 3C discharge and 0.5C charge.. but to confirm.

It allows me to have 6000W peak in a small package if I want

Link to the supplier
http://www.nkon.nl/rechargeable/18650-size/panasonic-ncr18650pf-3-7v-2900mah.html

 

[cwah]

You can get higher C rate cells if you want. I've chosen these ones for capacity and price mainly

 

[riba2233]

10 A discharge, 1C charge, but 0.5 recommended. Yeah, there are stronger cells, Samsung 25R, 8C discharge, 4A charge. 2500 mah, bit more expensive.

 

[MadRhino]

Needs a lot of them for the 100v 150A I'm pulling. There goes sinking the lighter weight dream. :|

 

[riba2233]

Needs a lot of them for the 100v 150A I'm pulling. There goes sinking the lighter weight dream. :|

Read better! Use samsung 25R instead. It's just a little less capacity, but 8C or 20A per cell constant.

 

[cwah]

Yeah you have to choose 2 out of 3
- price
- C rate
- capacity

I've choosen capacity and price: ncr18650pf.

What's yours?

 

[John in CR]

Needs a lot of them for the 100v 150A I'm pulling. There goes sinking the lighter weight dream. :|

With your light load you probably don't pull max current for more than a second or two. If you're concerned then simply parallel 5ah worth of RC lipo to cover short high current spikes.

 

[MadRhino]

Needs a lot of them for the 100v 150A I'm pulling. There goes sinking the lighter weight dream. :|

With your light load you probably don't pull max current for more than a second or two. If you're concerned then simply parallel 5ah worth of RC lipo to cover short high current spikes.

I can kill 30C Lipo in a single 6 miles ride in the mountain, even if I care to never discharge lower than 3.7v. They heat and smell and swell, and cells start to die as a consequence a few days later. That is because I carry only 24s 1p of 5.8 Ah for light weight, so I need to use the higher C rate. If I am using 2p, the 30C are good enough but the extra weight is a nuisance to my aggressive riding style, and at the end I am slower.

I am always looking to shave some weight off the bike, using Ti screws, handlebar, chain, spring... Yet there is a limit, for I need strong and stiff and reliable, so I can't shave everywhere.

 

[riba2233]

In that case use 130C nanotech, or something similar.

 

[MadRhino]

In that case use 130C nanotech, or something similar.

130C is a tad overkill, and expansive too.

60C is more than enough, they are keeping cool.