2.5 inch tall battery?

[slm9s]

I found a Santa Cruz VP Free for a long travel diy eMTB. I will use this for exercise so I don't need many AHs. Above the shock is a space about 11" long but only 2.5" high (with the shock upside-down). I was hoping to fit a "pocket rocket" 8ah battery, but it looks like they are 2.7" tall. Any suggestions? How tall would a 14s2p pack with bms be?
Maybe I could do a small custom battery under the shock?
I know I can do the backpack route, but I'd rather find a small battery to be in the frame.
Thanks!

 

[MadRhino]

Use the front top of the top tube if you are fast, or lower under the down tube if you are technical. Or, a combination of both if you go far.
Simple solutions are best. You barely have room for a decent controller under the top tube.

 

[slm9s]

Sorry if I was unclear, I have a BBSHD for this bike so no room for the controller needed.
And I will be mostly riding an hour or less so 8 AH would probably be enough.

 

[MadRhino]

Those are the spaces available on your bike. I would rule out the down tube because of the BB drive. Otherwise the front angle can be slackened with an angle set headset, and/or it could be built on 24’’ wheels to clear some suspension room under the down tube.

The front of the fork does offer a good place for 500 w/h and it is a place that is well protected in a crash. The top tube is almost as safe, and easily can fit another 500 w/h pretty slick. I would use both. Riding an hour can consume more than half a Kw/h if you are riding hard.

 

[MattZ]

Can you spin the shock 180 degrees, and have the reservoir toward the back and down?

 

[slm9s]

Can you spin the shock 180 degrees, and have the reservoir toward the back and down?

That's how I currently have it. (Pic is before I switched it, sorry if I was unclear) This gives the 11"x2.5" space.

 

[999zip999]

Here's a cheap battery I don't know if this would work for your needs but it sounds like it has good cells inside
https://endless-sphere.com/forums/viewtopic.php?f=9&t=112931
Remember cheap is not always good.

 

[slm9s]

Thanks, but that is 15" long, I can only fit 11".

I wish I could take the 1.5" height and change it to 2.5" and shorten the pack from 15" to 11"!

 

[999zip999]

I know nothing about him but he says he makes custom batteries in the bottom of the first post

 

[Hwy89]

A 14X2 pack, hot glued without cell spacers, would be ~ 10.5” X 1.5” plus whatever you use to encase it.

 

[E-HP]

Luna Mighty Mini:

 

[slm9s]

Luna Mighty Mini looks great, but they are out of stock. Anyone know of something similar in stock?

BTW, here's the progress on the bike, with a different battery ziptied so I could take a quick test ride...

(It looks like my chain is too short!)

 

[E-HP]

Luna Mighty Mini looks great, but they are out of stock. Anyone know of something similar in stock?

BTW, here's the progress on the bike, with a different battery ziptied so I could take a quick test ride...

That battery looks like it would fit under the downtube without a concern of the tire hitting it, even at full travel. How was the test ride?

 

[Chalo]

Luna Mighty Mini looks great, but they are out of stock. Anyone know of something similar in stock?

Just use the same philosophy for your battery as you did for your suspension.

https://m.aliexpress.com/item/4000430206355.html

 

[999zip999]

Yeah why not hang the battery under your bottom tube ? Options .

 

[slm9s]

I guess I was hoping for a small battery to fit inside the triangle for a cleaner/stealthier look AND to reduce weight for a better handling bike. But I guess you guys are probably right - what's a few pounds more when you're over 50lbs already.

Does black spray paint work on the bright blue shrink-wrap? Other options to tone it down?

The test ride was a gentle one in my driveway as I didn't want the battery to fall onto my back tire, but all systems were "go" and I feel like I could feel the 30a this battery can produce vs the 20a the "temporary measure" battery on my Turner Burner can give. More torque starting out.

Thanks for the help guys.

 

[MadRhino]

 

[slm9s]

When I'm mountain biking I come across obstacles I can't quite clear and need to unclip and put a foot down ASAP. I can't help but think I would rack my nads every single time with a battery on top of the TT. How do you not?

 

[E-HP]

Does black spray paint work on the bright blue shrink-wrap? Other options to tone it down?

I would make a case out of black polycarbonate or ABS (using a heat gun). It will provide additional protection/impact resistance.

 

[MadRhino]

...and need to unclip and put a foot down ASAP.
ride the trails with clips and miss the pleasure someday, to look at your bike flying alone, flipping and bouncing down the ditch.

I can't help but think I would rack my nads every single time with a battery on top of the TT. How do you not?

My bikes are tuned to let me put a foot from the saddle, so should be yours. And, the top tube is not a place to sit, unless both feet are on the same side of course.

 

[Chalo]

My bikes are tuned to let me put a foot from the saddle,

That's a motorcyclist's outlook. For a bicyclist, if you can plant your feet on the ground while seated, you're too close to the pedals.

There's nothing wrong with motorcyclists except that they're wrong.

 

[MadRhino]

My bikes are tuned to let me put a foot from the saddle,

That's a motorcyclist's outlook. For a bicyclist, if you can plant your feet on the ground while seated, you're too close to the pedals.

There's nothing wrong with motorcyclists except that they're wrong.

Once you put a motor on your bike, you are a motorist. Performance crank work is not a prime cockpit setting criteria anymore, and the heavier bike does require some ease standing on trafic lights. Dropper posts are a solution for those ebikers who like playing cyclists on their motorized bike. :wink:

 

[slm9s]

Ok, battery mounted.

I'm getting error 211 because the magnet is too far away from the speed sensor. I'll have to shim it away from the chainstay to get in range of the magnet I guess. Before putting the battery and motor on this was the easiest bike to wheelie I've ever ridden. Hopefully I'll get used to the weight and be able to do that again. This battery is a cheap chinese 48v 14ah that came with the bbshd setup I bought used off CL. Maybe I should still get a pocket rocket/mighty mini to lighten up the bike - especially the front end. On my 4 mile "shake down" ride I had to limp home as I didn't have the right charger adaptor and was running out of juice. I'll go for a bigger ride today, but everything seems to be working well. On the front velcro strap I have a pipeclamp around the down tube to anchor the battery so it can't spin. I'm not sure it was necessary, but I like to do mechanical diy things like that.

 

[E-HP]

....

Looking good.

If you decide to make a sleeve or box around the battery, then you may also want to run your cable/wires along the down tube instead of top tube to tidy things up a bit.