Battery under the down tube

[gensem]

After thinking about several ways to put the batteries in my bike.
I think my best option would be to put it below the down tube. I ll make sure the front tire ll not be able to hit the battery!
The frame in this picture isnt mine, my frame has a back suspension mechanism that uses most of the triangle area.

battery will be 20s 20ah lifepo4

500mm x 78mm x 100mm
12,5kg



Has anyone done this?
Any advice?

 

[Lessss]

Add fenders to keep the mud/wet off the batt too.

 

[auraslip]

Make damn sure the fork won't compress allowing the wheel to strike the battery, lock up, and throw you over the bars.
The best way to do this is to let the air out of the fork. This allows it to compress all the way down. Measure from there.

 

[neptronix]

^-- what he said.

The front wheel will kick whatever's on the road into the batteries.

Center triangle is the best place, if it is possible.

 

[dogman dan]

If you mount a fender, then that spray will be minimized. It will also show you exacty where the battery cannot contact the tire, since the fender wont. The space between the fender and the frame is your "extra" room.

Personally though, I think inside the frame, or saddlebag style on the top tube is better.

 

[sn0wchyld]

im interested in peoples views on this too, ive got a similar plan/problem to the op. im plainning on building a watertight pack out of carbon fibre, but ill now have to test how close the tires get when the shocks bottom out too. a backpack might end up being more likely than i thoguht...

 

[Ypedal]

Back in 2007

http://ypedal.com/Chaos2.htm

 

[gensem]

Nice looking bike Ypedal.

It either below the down tube using lifepo4 or maybe lipo inside the tube.

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14613

Price is good, but i dont know about lipo charging, parallel, series, etc. Im actually scared to try lipo. =(

 

[Ypedal]

Well, best thing to do is learn more before deciding.. start here :

http://ypedal.com/Lipo/Lipo.htm

it's a long read and may not make too much sense at first but keep reading..

 

[zombiess]

I'm thinking about using the same mounting location on my Diamondback Recoil Comp and enclosing 8 x 6s lipos in some 4.7x4.7 square PVC I picked up off amazon.com. I have the room without wheel interference during full compression so it seems pretty ideal.

 

[Memran]

Something like this?

 

[gensem]

Back in 2007

http://ypedal.com/Chaos2.htm

Ypedal do you remember what was the weight of that battery pack?
Did the bike handle well with the battery below the tube?

thanks

 

[LegendLength]

IMO the best mounting option for bikes that have the triangle full of suspension is to get 3s lipo blocks and tile them over the sides of the triangle. Use sheet aluminum to cover the batterys on both sides so they don't hit the suspension and they don't get hit by the outside world.

Purchase an alumninum bending brake off ebay for $80 and a jigsaw cutter from a hardware store for $50. Then the sheet aluminium is about $50 for 2 foot x 5 foot. Get the 1.2 mm stuff it's the best for bending yet it's strong enough to keep the lipo safe. You'll also need a few other things like file, drill, rivet gun and foam padding.

All in all it's expensive and takes quite a few days for the first try but it's well worth it for fitting in the maximum number of batteries possible and still having it look good. I've done similar although my triangle was open which made it easy. I was worried at first using the saw because i'd never done anything like that but after a few cuts I felt like a pro.

 

[gensem]

After studying even more and still loving ping.
I think I ll be forced to used to LiPo.
Lifepo at 20s 20ah is damn big!!!

Now im thinking about using 8 of thoses

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14609

Making 2 10s 20ah packs

Or maybe a 18s 16ah pack using this ones

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=16228


Im just not sure about how to charger thoses pack with the less amount of trouble. I wanted something as close as plug and charger as possible.

Any advices?

 

[auraslip]

Im just not sure about how to charger thoses pack with the less amount of trouble. I wanted something as close as plug and charger as possible.

Welcome to lipo. Enjoy building and engineering your own bms

BTW, if money isn't an option, cell_man sells a123 packs complete with bms and chargers. Because of it's higher C-rate you could get by with a 10ah pack.

 

[auraslip]

Im just not sure about how to charger thoses pack with the less amount of trouble. I wanted something as close as plug and charger as possible.

Welcome to lipo. Enjoy building and engineering your own bms

BTW, if money isn't an option, cell_man sells a123 packs complete with bms and chargers. Because of it's higher C-rate you could get by with a 10ah pack, and he could build it in what ever shape you want. He could make it so it clears the front wheel and cranks,.

 

[gensem]

I need higher capacity because I cannot charge at the street. I think 15ah would be the absolute minimum for my ride.

After thinking abit more Im now currently leaning to 18s 2p 8000mah zippy.
Just one charger needed with a paraboard, 16ah capacity and weight will be below 9kg.
And I can put 3 battery in each frame side, doing 18s in each side.

Price ll be under 1k with a powerfull mean weal powersuply a 1000w charger + paraboard and 6x 6s 8000mah.

A123 cells from cell man ll weight around 10.5 kgs
I ll drop him a line just in case because I ll only order the goods in 20 days.

regards

 

[sn0wchyld]

IMO the best mounting option for bikes that have the triangle full of suspension is to get 3s lipo blocks and tile them over the sides of the triangle. Use sheet aluminum to cover the batterys on both sides so they don't hit the suspension and they don't get hit by the outside world.

Purchase an alumninum bending brake off ebay for $80 and a jigsaw cutter from a hardware store for $50. Then the sheet aluminium is about $50 for 2 foot x 5 foot. Get the 1.2 mm stuff it's the best for bending yet it's strong enough to keep the lipo safe. You'll also need a few other things like file, drill, rivet gun and foam padding.

All in all it's expensive and takes quite a few days for the first try but it's well worth it for fitting in the maximum number of batteries possible and still having it look good. I've done similar although my triangle was open which made it easy. I was worried at first using the saw because i'd never done anything like that but after a few cuts I felt like a pro.

pretty much exactly what im planning, though i went with 5s packs because they were on special. plus wireing 1.2kwh of 3s packs is way more involved than the same of 5s. so jigsaws work fine on sheet metal?? I was thinking id have to use a angle grinder or something!! hehe.

thanks for the tip on the bending breaks, wanted one of them for eons.