battery issues

[deacon]

For me it is not so much about the speed but the range. We can buy the size motor for the speed we want but the battery consumption is what it is not much you can do about it soooo. Lets start a thread to compare and give battery tips...

My suggestion is we use this formula.... battery ah rating divided by miles range (real world not a pipe dream mfg figure).

My motor is a hub 24volt 250 watt.... I figure its 4 miles on 12ah battery that would be a 1mile per 3ah rate.... I suggest we go with the 1/3 ratio and compare different motors. Mine is an ez-glide. That is riding it wide open not conserving batteries at all. Conserving I was able to get at least five miles probably 6 but it isn't nearly as much fun to ride that way.

When I get my friction built I will have a ratio number for it as well...

I really am curious as to your motor and it's ratio.... I will probably be buying more kits or building more bikes of my own. So please join in with your figures.

My test track is the hood where I live. I measured out two miles with my wife's car then ride it with my bike in laps. Please join in....


so in conclusion
ez glide 250 hub motor 1/3 riding wide open on hills and flats mixture of area 220 lb rider.

[ebikelover]

I've got a Pedego Comfort Cruiser with 500 watt hub motor and 36 volt lithium battery that goes 20 mile no pedaling with me at 190 pounds.

[deacon]

Does the litheum battery have an amp rating so we can kind of compare...

[Michigan Mike]

Originally Posted by ebikelover

I've got a Pedego Comfort Cruiser with 500 watt hub motor and 36 volt lithium battery that goes 20 mile no pedaling with me at 190 pounds.

Hi Ebikelover,
Can you tell me the deminsions and weight of your battery? Also how many times can it be recharged and what would a new one cost?
Thanks.
.

[deacon]

I did a very unscientific battery test today. I ran my hub motor a measured mile... then ran the friction drive the same course exactly. Both battery packs are the same type and rating. One is new the other has been charged a dozen times.

The results the used pack on the friction drive ended the course with a charge of 13.06 volts.

The hub motor ran the same course with the brand new batter pack with a full charge. It ended with a power charge or 12.87 volts.

I ran both of them at full throttle the whole mile. The hub had maybe 20 to 25 percent more power. It wasn't a great amount but it was noticeable. It was in both torque an speed. The hub motor is regenerative so it probably will last longer. I will start the range tests tomorrow. I will also have the better surface on the drive wheel of the friction bike tomorrow. The better drive will give more torque and maybe some speed but it might also negatively impact on the power consumption.

[deacon]

I was afraid that the new batteries might be bad so I took them out for a range test after I recharged them. They started flashing yellow at about the same time as the other so that isn't the problem. Obviously the hub motor pulls more current than the friction drive.

Which makes perfect sense if the hub motor has more power. Tomorrow is supposed to be cold so the range test for the friction drive with the better roller surface might have to wait a bit. I really am curious to know the deal with it.

[rearengine]

Deacon..
I will be watching for your post.. I'm about to make a purchase, hub, or chain like the Currie gear drive. What is the watts of your friction drive motor? Are we talking mostly SLA deep cycle batteries in our bikes? What I know about Amps & watts is silch..I've always been a gas man, but getting so I don't like the noise in my old age.. Bill

[deacon]

Originally Posted by rearengine

Deacon..
I will be watching for your post.. I'm about to make a purchase, hub, or chain like the Currie gear drive. What is the watts of your friction drive motor? Are we talking mostly SLA deep cycle batteries in our bikes? What I know about Amps & watts is silch..I've always been a gas man, but getting so I don't like the noise in my old age.. Bill

I am running a hub motor 250 watts and is a low power helper unit at best. I have heard that the 600 watt is a good size but I think it is still less than a china kit for power. I bet the 1000 watt one is pretty close though.

By the way I like mine size and all. I need the exercise and I won't pedal unless I have to so it works for me.

I have two friction drives... I tested the 300 watt and it tests about 75percent of the hub motor. I have what I think is a larger motor but the tag is gone. I am going to test it tomorrow with a good drive wheel and see what the range is on it.


I am running heavy sla batteries 12ah versions. I can get about four miles on mine before they start to fail. I can get another mile out of them even when they are dying. I am going to do a range test on my friction drive tomorrow to see how it goes. By carrying a second set of batteries on a trailer that is low resistance I should be able to increase the range to ten miles.

[deacon]

I happen to have a couple of very old 12volt flooded lead acid batteries meant to be used on lawn tractors. I used them with one of my old old friction drive setups. Something to do with two engines. I think I will spend this rainy day testing a couple of them. Even if they don't have enough power I can pull them on one of my trailers to see how much drag they are on the hub motor.

If it isn't too much, I might give them another try. They are not very expensive and very easy to find in any town. Most are under two hundred max amps, I am not sure what that is in amp hours. I will have to see if I can find a calculator for it.

[toytime]

From reading stuff on the ebike sites Chain drive Currie like systems are more efficient than hub. I'll be interested in knowing how those tractor bats. work out for you deacan.
I just paid $120 cash for two 14 amp bats. and feel that lawn tractor bats. may offer more power and range for less money.