Battery questions

[Iandayen]

So a year ago I bought a BBS02 motor with a Samsung 48V 12Ah battery.

http://www.ebay.com/itm/Bafang-BBS02-750W-Mid-Drive-Motor-Ebike-Kit-2016-Slim-48V-12Ah-Samsung-Battery/222021063577

I love it, it has been great for me - I weigh 205lbs and ride this thing a lot - I have put over 700 miles on the bike now.

I want to use it for longer distances and was thinking of getting a second backup battery.

I live in Colorado Springs - nothing is flat, it's all hills and a lot of them are steep. I am not able to pedal much (knee problems) so I rely heavily on throttle only mode.

I average 10-15 miles a charge with my current setup, cruising around in 1st gear at roughly 17-18 mph. Short range is due to hills. With a 7 gear rear cartridge on a flat surface I get 18mph in first gear with me riding it, going up a couple hills I normally go up it drops down to 13-14mph (sometimes even as low as 10-12)in the same low gear.

I plan on getting a new bike as well, I need disc brakes in the rear (current bike only has front disc brakes - cheapo walmart crap bike lol), but I'm hoping to get one with a wider range of gears to help on the hills.

My main question is what would you guys suggest as far as a battery goes. I am just finishing my associates in electronics, I am familiar with wiring and am not afraid to do so, but I don't want to build my own cells, so something pre-built would be nice. I would like it to be able to fit on a rear rack as the one I have currently fits into the frame. I can comfortably change out the connectors so both batteries work and I can just switch between them as well.

 

[BBassett]

I suggest you get the largest Amperage 50-52V you can buy and fit on the bike. I have a 24.9Ah battery that gives me 14 to 15Ah to use on a ride and still not stress the battery.... don't charge over 80% and don't discharge past 20%. This will give you a much longer battery life. Subtract 40% from a 12Ah batter and see how far you get. I average 2+ to 3+ miles per amp hour riding a bike that weighs 115 lbs. and my 290 lbs. of old ass. For me its about distance not speed. Using the minimum power in the right gear is still leting me average 13-16 mph at distances of up to 60 miles.

 

[Lurkin]

bike:
You'll find there's more benefits to buying a better quality bike than just braking capacity. In fact, these bikes can provide misleading views on things. I've recently kinda been taught a lesson over disc/non disc brakes, finding v-brakes are actually awesome, cheap and super easy to maintain. After all, they turn the wheel effectively into a massive disc. The only reason for me to resort to disc brakes now is my astounding ability to run wheels out of true :lol: drivetrain quality, shocks, frame material, weight... list goes on of other things that can improve.

battery:
I take it you want more range. Another shark pack is the easiest means, because you can recycle the battery mount you already have and just switch them over. I think you'll find this the most cost effective/straightforward option.

Alternatively, you could look at a pack with more capacity, either with the same number of cells of a larger capacity, or a pack with more cells. Pay attention to the cells used, INR18650-29E are a 2900mah cell, which is what you linked to. Totally possible to see 3500mah cells these days, increasing your capacity for the same weight.....

If you update your details with your area/rough location, suggestions of where to get them from can be made....

 

[ColinB]

If it were me, I'd go with a single larger capacity battery. Or buy a second battery that you can parallel with your existing pack. You MIGHT find your range with the parallel batteries is more than the sum of the individual batteries. (Because each battery is delivering 1/2 the current.) The only problem is if the batteries are not equal in ability, one will work harder than the other.

Lots to think about! Personally, I went with 20ah 48v LiFePO4. A bit overkill, but it is lasting well.

Colin

 

[drew12345]

A large capacity triangle battery in frame would be best. That way you just deal with one battery and have best handling.

But if u r on a budget and trying to extend off what you have, I guess a battery from Luna or em3ev would be nice. You can mount on handle bar, top tube, backpack, or rear rack. Each affects handling.

Maybe instead of paralleling, you can just disconnect one and connect the other when needed.

 

[motomech]

Depending on your lifestyle, you could consider LiPoly.
It's approx. half the cost, size and weight of any other chemistry and the hazards of using it are exaggerated.
But it time consuming, checking cell balance, keeping an eye on it while charging and in general, fussing over it.
Not for those with a busy life.
I'm retired and ebikes are my hobby, so I don't mind spending the time;
And then there is the charging equipment. I have a hundreds of dollars of it, but a passable set-up can be done for $100
The small frame bag holds 10.4 Ah (46V) that cost me $170(it was on sale) and weighs less than 6 lb.s;
The bottle holds 3 Ah and I'm working on a 4.8 Ah version using round cells.