Battery back pack ideas

[zippy500]

Hi Everyone,

In a effort to look stealthy in my ebike build , looking to fit BBSHD I was debating where to fit the battery, I was thing of rack version, but i am reading that having a battery high up and cause the bike to feel top heavy!

Soooo Im thinking to build a battery back pack, has anyone used/built one, I dont want to put a brick shape battery in a back pack, any ideas on configuration.

Thanks

 

[dogman dan]

IMO,, under 10 pounds of battery is fine on a rear rack. I get crap for saying this here, but it's not that big a deal.

YES,, it does affect handling, yes, you can feel it. But no,, it does not make me crash, even on difficult single track trails. And,, IMO,, a back pack does affect handling while riding a bike, climbing, skiing. But not one under 10 pounds. So about the same weight limit for both.

Seems to me like a brick would be a good shape for backpack, but not a cube if that's what you mean. Any shape still 3" wide on one side should work fine in a pack. the typical rack battery shape should be excellent in a pack, so why not try that, and try carrying both ways?

 

[Phife]

Ive tried both on my full suspension Stumpjumper bike, They each have their pros and cons.
I got a 10lb 52v 20AH rectangle pack, It fits in both my backpack and a trunk bag for my rear rack. Its the NCR18650 pack from Luna Cycle. Ive padded it with 1/2" Adhesive backed CC Neoprene and recently a 3D Printed hard case for extra protection to the pack.

I use the backpack for trail and single track riding, I feel I can move around better with it on my back, I feel better balanced and it looks more stealth, Bike is also lighter so its easier to load onto things like bike racks and chair lifts. The downside, 10lbs on my back can make it sore after a full day of riding. I feel it in my shoulders and lower back. I even have a good backpack with wide straps and a belly strap. Have a look at my thread, its in the link below.

I like the Rear rack for when I'm traveling on the roads or rail trails. Anything smooth and relatively flat. I can easily go 80-100km or more like this and not have a sore back afterwards. Rack defiantly makes the bike rear heavy. Even setting the bike down on the ground and picking it back up again is a bit of a struggle as it just wants to turn on the handlebar and back wheel. Its also noticeable when climbing, front wheel wants to come up much easier. Also, the rack can interfere with the full suspension travel, its a seat post rack so not the best setup. Might be better on a hardtail, but not really suited to the bumps and jumps I like to do with that bike. Plus, the battery still moves around a little in the trunk bag, it really needs a rigid mount to the rack to work well.

I think it will come down to how you want to ride your bike. Dogman's idea of the rack shaped pack is good as you can use it for both, though its limited in the total AH.

If I was to do it over again, I would go with a smaller pack for the backpack, something around 5-6lbs and 10-12ah would be ideal for me. Or just say screw the backpack and stealth and mount the battery in the frame again. Its really the best spot. No one ever really notices I have an ebike anyways.. I usually have to tell them.

 

[Drunkskunk]

Nothing wrong with a rack mounted battery. There are better places to mount them for balance and handling reasons, but that doesn't mean a rack mounting is bad. Sometimes putting a bag on a rack to hide the battery is the best option. One of my ebikes uses a rack mount. it's fine for riding on the street at reasonable bike speeds.

If you plan hitting the trails, then you want the battery mounted in the frame. if you need stealth, consider a triangle frame bag.

http://lunacycle.com/batteries/battery-bags/luna-cycles-triangle-battery-bag/

 

[LockH]

Talk about yer "brick" (size and weight). My first "ebike" was actually a standup kick bike. 2x 12V 10Ah SLAs stuffed into a metal tray under the deck the rider stands on. Point being only that this tray and batteries hung lower that the wheel axles! (12" tubed tires on those wheels). I image it actually helped offset the weight of the rider on top (and standing up). Given handlebars also supported by long upright metal post, def. made the "scoot" easier to "throw around" while underway.

Just my 2.something cents :wink: Cdn.

 

[Paladin]

I started using a back pack for stealth but you are generally going faster than a normal cyclist, kinda gives you away.

I like the pack. 10lbs would be about it for me too, as far as comfort.
pros
I can carry tools and air pumps. Tire/shock pumps.
If bike gets stolen they don't get your battery/tools.
Makes the bike feel more 'bicycle' like.
Cant accidently grab the throttle and gas it when your not on the bike because your battery is unplugged.
If you crash you come unplugged, less after crash runaway throttle issues.

cons
Its hotter in the summer, back sweats.
Heavy jackets can get in the way a bit in the winter.

Low in the frame would be the best place but if you don't have the room the back pack works good.

Check out my builds, nice and short. Some Pack pictures.

 

[LockH]

So far in this thread "vibration" not mentioned once?

My current Li pack came in a "huge" (recycled, black plastic) case, where it's more than half full of thick foam padding (and air). The bunch of cells wired together is relatively "tiny".

Just a thought...