How much battery is too much?

[RoadWrinkle]

:lol: :lol:



Photo responses are welcome....but really want opinions about the threshold between power/range and weight/agility of the bike itself. In other words, what is the largest most powerful battery size that can reasonably be managed on an average bicycle before you have the battery dictating ride characteristics totally?

 

[wesnewell]

Depends on where you mount it. You can put a lot in the triangle area without much ill effects. Anything you put on a rear rack will be noticed.

 

[dogman dan]

The short answer is that it's too much when it won't fit in the triangle of your bike frame. If no triangle, then the compromises begin as you see in that pic above.

It's too much when it affects the handling of the bike excessively. My own opinion is that carrying more than 15 pounds is a son of a bitch. Even on a big cargo bike, it's nicer to have 15 pounds or less. Even carried perfect, in the center of the bike, more than 15 pounds affects handling more than 5-10 pounds. That's why lico might be worth some risk for some bikes.

But it depends on the ride. Dirt riding, I decided to shorten but improve the ride. I now carry less than 4 pounds of lico on the off road bike. Short rides suit me now, since the chronic fatigue is well, chronic.

Size matters too, and can affect where you mount that weight. As Wes just said, it matters a ton where you mount it. I tell people over and over not to buy a 48v 20 ah lifepo4 pack, unless they will carry it in panniers. It's too big and too heavy for a rear rack, and too big to fit in a triangle of the bike. Many bikes have triangles big enough to just fit a 48v 15 ah lifepo4 pouch cell pack. So I tend to recommend that, or identically sized 36v 20 ah as the max.

In addition to fitting in the triangle, 48v 15 ah of lifepo4 weighs about 15 pounds. Lots of bikes are now using limn, which is smaller and lighter. Depending on the shape, 48v 20 ah of limn might fit fine, and still be not much over 15 pounds.

But even with smaller and lighter limn, or lico, it's still going to ride nicer with 12 pounds, than with 17.

 

[MadRhino]

It is too much if you can double your usual ride in ideal conditions, because you are carrying extra weight that is not needed.

No matter how much, it is too much if it interferes with your riding position.
And it is also too much if it compromises proper handling of your bike.

Modular design is best, so you can quickly adapt to carry what you need.

 

[rojitor]

I need 15ah most of the cases, 18ah if i am in a rush so i did a 20ah pack. The maximum i can spend on my commute is the limit i have set for me.

 

[eva-michael]

For LiFepO4, 48V 15Ah, 36V 20Ah
48V 10Ah-12Ah 36V12Ah will be more convenience. But lower distance.
48V 20Ah will be a bit too heavy to carry even in the rear rack. About 12-13KG.It will be better to think about how to put such such heavy battery and then ask some one to custom build as per dimensions you need.

 

[speedmd]

This guy needs all he can fit!

 

[speedmd]

Definately worth having a bit extra battery to keep the brew cool also. 8)

 

[lbz5mc12]

Here's some pics of my bike with battery placement. I'm also going to show a pic of the torque arm/plate I made by cutting off the rear dropout from my broken Currie frame. The middle battery is a 36V 20A and the rear is a 48V 10A. The rear bag also has the controller in it and I have a folded up old T-shirt underneath the battery for cushioning. On the middle frame bag I daisy chained multiple zip ties from the front and bottom of the bag to the frame to stabilize it because it swayed so much it made the bike feel off balance big time.

 

[RoadWrinkle]

Here's some pics of my bike with battery placement. I'm also going to show a pic of the torque arm/plate I made by cutting off the rear dropout from my broken Currie frame. The middle battery is a 36V 20A and the rear is a 48V 10A. The rear bag also has the controller in it and I have a folded up old T-shirt underneath the battery for cushioning. On the middle frame bag I daisy chained multiple zip ties from the front and bottom of the bag to the frame to stabilize it because it swayed so much it made the bike feel off balance big time.

Nice configuration and great parallel switch. I guess running parallel batteries is an option if you know what your doing, I would not want to create an eBomb (LOL).

 

[RoadWrinkle]

Definately worth having a bit extra battery to keep the brew cool also. 8)

Imagine the money you could make with this bike tooling around the parking lot of large concert and Football venues. The best thing about this is not just the sense of humor displayed, but the effort and expense that was invested in the "humor", LOL. :lol: :lol:

 

[speedmd]

It would have to be a save the earth concert / tree hugger convention for certain. Not sure they would not get the ATF and home land s... after you if you have too big a box with wires coming out of it I can see it, "organic ("home"), micro brew", Let see, they would get you for all kinds of violations once the inside vendors spotted you. :lol:

 

[lbz5mc12]

It's actually not a parallel switch, It's a battery 1/battery 2 switch.

 

[Kingfish]

>> OP:
When you've reached beyond the practical point of return on investment. Arguably - I was carrying more battery in 2011 than I was getting in return due to the weight penalty.

At present I am loaded up in the Triangle with 15S6P / 63V@30Ah, plus Saddlebags with 15S4P / 63V@20Ah (totaling 30 LiPo bricks). With this combination I can travel 90 hilly miles. Doubling the count of batteries does not equate to double the distance as clearly represented in 2011: I had in fact 78 batteries 15S26P / 63V@130Ah which equaled 100 lbs. of LiPo, yet the farthest I got on a single charge was only about 165 miles. Granted it was hilly and windy, and I also carried a lot of gear, tools, and parts.

Together, this bike with rider weighed between 400 to 450 lbs.

In brief, I'd say it's too much battery when it interferes with performance.
On a diet, KF

 

[Gazz]

i do hope that rig is 3WD, if it isn't, why not

 

[RoadWrinkle]

>> OP:
When you've reached beyond the practical point of return on investment. Arguably - I was carrying more battery in 2011 than I was getting in return due to the weight penalty. In brief, I'd say it's too much battery when it interferes with performance.
On a diet, KF

This basically sums up what I was thinking about...well put, Kingfish and thanks.

 

[RoadWrinkle]

So in terms of power vs. battery weight, this is THE issue. Beyond eBike applications, there are battery technologies on par with inventions like the light bulb, automobile and PC waiting to be invented. If someone can come up with a battery with energy output that far exceeds its own mass...this would change the world, literally.

 

[John in CR]

How much battery is too much? It depends where it's located and the nature of your riding. If you run the streets, rarely need to pick up your bike, and have good placement, so you don't really feel the weight, then big batteries are great. Conservative use leads to much much longer battery life. I've had a 2.2kwh pack on my SuperV for a few months now, and loving it.

 

[parajared]

Doctorbass posted a crazy looking build on evalbum.com: a 246 kilometer one charge bike with 2.21 killowatt hours of batteries on it.
http://www.evalbum.com/1947

 

[amberwolf]

The short answer is that it's too much when it won't fit in the triangle of your bike frame. If no triangle, then the compromises begin as you see in that pic above.

That's assuming it's a "typical" bike. If it's something like my monster, well....

But too much for me would be more than I know I would use, if I had a planned route, known conditions, etc., with a margin for detours and wind. Unfortuantely much of the time I don't know *for sure* how much I will use, cuz my route may on a whim or sudden remembrance of things I have to pick up include several miles of detour, or a windstorm that uses up huge amounts of extra power (like the storm earlier this week that took another 5Ah or so to fight the winds!).

I like having my 35-50 miles of range, for instance, but that's two packs, neither one all that light (a 50cal ammocan full of 14s 1p 20Ah EIG, and a 7.62mm ammocan full of 14s 2p 5Ah RC LiPo, for 30Ah ~58V). It's heavy, and bulky. If I had it on a normal bike I'd have to bolt it to either side of the rear axle, at that height, to keep reasonable handling.


For my normal work commute from my house before the fire, all I would would be half of the 7.62 can's contents, with little margin. For my normal work commute now from the apartment, it'd take the 50cal contents, with a little margin but not much. So I just keep both on there, just in case--and it has saved me trying to pedal home the last few miles wiht my bad knees on a bike not designed for it, a few times (like in this windstorm). Of course, I could carry a charger, but normally I don't want to sit somewhere I can watch the bike for 2-4 hours or more to get enough charge to get back home, and I don't trust the chargers I have to not break from vibration (one already did, though I fixed it easily enough).

 

[dogman dan]

As always the answer is "it depends" I tried to sort of say that before.

Kingfish is the king of carrying too much. If you do carry too much, do it just like he did.

Before I got sick, and had to give up long rides, I often carried 1.5kwh of lifepo4. Just about 32 pounds of battery including the protective boxes for them. My bike was a front hub, which let me get away with carrying a lot in panniers. On long rides, I carried up to 50 pounds including the batteries. 60 mile range was easy, but slowing down enough could get me 75 miles.

How did the bike ride loaded with two batteries instead of just one? Like shit. But on those rides, I wanted to ride below 20 mph, and the handling was tolerable enough for that. I took a great deal of care descending large mountians, and cornering in the city. But it worked OK enough.

Love seeing the old pic of docs blackcomb. It made me go find this one, and build this. The battery was about .75 kwh, to preserve decent handling. It still interfered with pedaling, but this bike was never pedaled more than a few yards. It scampered up steep hills easily. I tended to ride it standing up, trials style.

 

[dogman dan]

Now that I'm sick, I don't ride dirt much more than 5 miles at a time. So I put the same 12t motor on another bike, with better suspension.

I carry the battery wrong, but at less than 4 pounds, It handles fine. Occasionally I carry 8 pounds, and notice the weight then. So for this bike, 8 pounds is too much carried on the rack like that.View attachment 1

When I ride a long distance on street, this is what I use to carry up to 2kwh of battery. .75 kwh in the triangle, and the rest in the panniers.

It handles much better with nothing in the panniers, but I can comfortably ride 30 mph with this bike, carrying 30 pounds of battery, and full camping gear including two gallons of water.

 

[kdee122]

I have 20AH of 32s A123.

Good for around 100km on Downhill knobby tires at low speed or more than 60km (my two way commute) with lots of stops and starts and red lights stop speed on my way to work is typically 60kph average of 25-30kph.

 

[Ykick]

Depending on chemistry 10-15Ah, 50-60V tends to be my sweet spot. If I need more than that I go with a spare battery or two in backpack or basket and just swap it out when needed. Majority of my rides don't require more than 10Ah and I enjoy how the bike fits and feels with 6lbs small'ish RC Lipo instead of 20lbs or more of bulky, ugly weight.

 

[shenzhen_ex]

20ah of A123's
I think it rides great (when it is not broken).