Where to put it ,,auto battery test and evaluation.

[deacon]

I began this test with lots of other things going on that pieced together to end up with this. First of all I'm honestly going to try to stay on point here.

I built a home made trailer that is pretty small considering it is hauling around two automobile batteries. What the heck? I am sure you just asked. Why would anyone do that.

I just wanted to see what a car battery would do. I was in the midst of building a Trike because my balance isn't so good. I needed something I could ride on a trip that might run five miles at the most. I got the Etrike finished but before I even tested it, I got side tracked with the auto battery experiment.

Here are the elements I have now and what they do.

Okay after rebuilding the battery trailer a couple of times I have two auto batteries (both used) sitting on a trailer made with two electric scooter wheels and tires I had laying around. The trailer bed it about 9.5" x 12 inches. Once i got all the drag out of it, the effort required to pull it around isn't too bad.

I have it attached to a two wheeler with a friction drive motor on the rear wheel. The motor is really the rear assembly from an electric scooter sitting on top of the rear wheel. This isn't about the bike though, it's about the batteries and maybe a little about an overall ride.

Okay so after having tested the bike riding around the neighborhood, I felt pretty confident that the outfit would work well enough. So this morning, in spite of a nasty head cold, I took off on a ride in the real world.

When I pull the batteries off the charger the pack reads 25.75 maybe a little more. I left home pulling the trailer up a gentle hill with my bike. Top speed is a blazing 6 miles and hour. I have the bike geared so that I can pedal it while the motor is running. There is no throttle. The drive is on or off. Pedaling helps with the battery drain and to keep the heat down from drag.

So when I got to a long downhill section of almost a mile, I lifted the motor and coasted with a little pedal assist. When I came to the end of the downhill section I dropped the motor and off I went, still pedal assisting it. Now when I got to what I call bike killer hill, I was able to run the motor and pedal assist to the top. It did cause me to do some heavy breathing but I need that. I could never have made it up that hill, not even a fifth of the way, without the engine.

So when I got home I read the pack and it was 25.10 volts. At 24.5 it begins to sag so I had a couple of more miles in it. I wanted a bike that I could ride to the store, or ride for exercise this is it.

Now what did I notice with the heavy battery pack.

1) It has enough power reserve to do as well as SLA batteries that would cost me twice as much. That is only because these were bought used.
2) the little trailer cuts down on the weight of the bike itself. It is also easy to pull.
3) The heavy trailer makes downhill coasting not a problem at all. It seems to push it along.
4) I definitely get exercise when I go up a hill with this thing and try to help it out with this high gear ratio.
5) for some reason this doesn't cause the circuit to overheat. Probably because I tend to pedal it a lot more.

THIS IS NOT FOR EVERYONE but for something to ride to work out or go for a bottle of milk, it will work just fine. If I was going to build one from scratch without all the parts I had laying around what would I do.

Buy the 90 buck full suspension bike from walmart.

Attach a friction drive motor to the seat frame. I would use a scooter rear end again and just hang it onto the bike. I like just the switch with no throttle personally.

Build a trailer from alum angle pieces. Use SLA batteries.

 

[rustycase]

Well that looks great Deacon!

How many watts is that motor?
What kinda scooter was it that you axed?
and it doesn't build too much heat on killer hill?

...I got an E200 razor here, to cut up... but I think it's too small???
and of course, the batteries are pretty dead.

So this trailer and drive rig is gonna go on your trike???

Best
rc

 

[deacon]

Well i had to reevaluate... lol

the car batteries were not the best idea I ever had i think. the motor I bought on ebay. It is 350 watts at 24v I have run it at 36v and it produces about 500 watts which is a much better performance.

I am about to go back to sla batteries since I got a deal on amazon. Two 12v 24ah for 98bucks delivered. I also have a 6volt 40ah nimh battery I built to bring it up to 30volts which is a really nice power amount. That should raise the motor to about 425 watts. That should be a pretty good assist motor if I can get the weight down and the gearing right.

I am going to buy a brand new (gasp) multi speed mt bike at wallymart to put my motor on and to pull my new lighter weight trailer. It should improve my experience.

The car batteries did fine for a while but within a dozen deep charges their performance has changed somehow. they don't put out the amps they did at the same voltage as before. At 25.5 volts they pulled really well at first, now at 25.5 volts they are pretty flat. When they are flat on an even moderate hill they wear an old man with a bad heart out.

When I get this new set up working I hope it will be easy to build and cheap with almost no maintenance issues. When I was building E bikes before I found the throttle and controller to be the number two issue. The battery being number one. Battery I'm still working on but the others I have beat. I found that a 30v maximum on a 24v motor will run without burning simple house wire or 20amp household switches. So an extension cord and a 20amp switch will get you into the ebike business. I quick pull wire loop to open the circuit is your emergency switch should it do a melt down. The the rear wheel of a scooter laid on top of the bike wheel is your drive wheel. The drive wheel should slip before it over heats. At least mine do. Also I tend to pedal more these days which is good for my fat butt.

The auto battery's weight is prohibitive as well. I built a much lighter trailer for the sla which are on the way, team that with the lighter batteries and the multi speed bike and it should be a good lil system.

I am going to have to test it more. Since I don't use a throttle I need the multi speed bike so that I can assist the motor. more of the time. I can run the bike at lower gears with no motor assist some of the time on flat ground. Gear up a little for down hill to push it along a little faster. Then gear even higher when the motor kicks in so that I can begin helping it pull up the big hills without waiting for the hill to drag it down. and of course go to the lower gears as the motor drags or the batteries go flat. I think this will work but it needs to be tested. So stay tuned lol./..

 

[deacon]

Okay the batteries sla 24 ah and 24v showed up today along with the rain I am waiting for the rain to end so that I can do head to head test with used auto batteries vs new sla batteries... It should be interesting for sure.

I got to tell you the weight difference isn't all that much. I have a nimh battery I build from c cells that is the right weight but it doesn't perform well. I would love to try a lithium but for a test they are just too expensive for an old man like me.

 

[deacon]

I would like to report that the auto batteries were an absolute and total failure, but i did get some really good exercise getting those monsters home when they went flat.

I rebuilt that small trailer after I recycled the batteries to the auto parts store. Installed the 24 ah batteries and tested them with the one speed bike and they work fine as a pedal assist with the friction drive. My next move is to a full multi speed bike. That's my move whenever they get back in stock sold out at the moment.

 

[killercanuck]

Are you sure the cars 36v weren't prematurely cooking the poor little 350w motor by running it at 500w? Or something was cooking screwy in the controller... hmm.

Great to see you trying new things, even if they fail Helps out everyone, eh. We all need to start a buy deacon a beer fund, heh heh.

Have a good one.

 

[deacon]

actually the motor is running as good as ever. The batteries would do about a mile and read flat. It was a case of them putting out their charge too quickly. I am not using a controller at all. Just a simple home light swtich but the 20 amp version the 15 amp will fry on you, Im trying to find the simplest motor possible for pedal assist.

The 24v power pack is fine for pedal assist enough gears to chose from I think. The big 24v battery pack and the light weight trailer seem to be very well suited for this project. I now need to move the drive system to a multi gear bike. I am going with a full suspension model so that I don't have to lose the brakes but I need to get one first.

I think that will be the final piece in the puzzle and my wife will be happy as long as I continue to wear my bike helmet. lol,

 

[rustycase]

Well that's disappointing news to hear, Deacon...

I opened up my E200 to charge the batteries individually, because I have no 24v charger for it. After repairing the broken speed control, it didn't run far, or fast.
I figger the batteries were weak and was planning on carting around a couple auto batteries. Guess that doesn't perform well.

So I might sort through my RC battery chargers and see if I can make internal changes to one of them to put out the 24+ volts to use on the E200.
Got some pretty fancy RC chargers from back when. Hope I can mod one of them. There's a lot I don't know abt battery chargers!

If I could get 15mph for 20 minutes run time it would work well enough for me to make it worthwhile...

No more deep cycle batteries around I once used on my trolling motors.
They left with the last boat I sold off.

Still got a couple electric trolling motors left. Maybe I could sell off the best one this summer and get enough to buy some of those SLA batteries you like, when you find out which ones work best.
Best
rc

 

[deacon]

Here is the skinny so far. I rebuilt my trailer to drag the two 24ah 12v batteries. That was a good thing. Kind of funny though I built the trailer using the scooter wheels. They work better than the bike wheels, I think, so far. I might try the bike wheels again some day.

Like you Rusty I was looking around the shop for something to build the trailer bed from and I found a plank. That looked good until it split in half while I was working on it. Then I ran across a half inch thick plastic cutting board I used to trim cardboard for cameras I built. Since I don't need it as a cutting board I turned it into the bed of the trailer. I bolted on a couple of hangers and a tongue. I got the wheels mounted and I rode it today. I had to shorten the tongue to keep it from swaying but it works real well to pull those batteries.

The motor works fine to help with the steep or long hills. The mountain bike I used for a test frame is now a one middle range gear so I ordered a new bike from Walmart. When it comes I am going to mount the motor on it without changing anything from the original bike.

I should be able to pedal some with the lower gears to help get it started. But mostly being able to change the gears will help with the big hills. The higher the gears the more I can pedal assist the motor. I am looking forward to riding around more, once I get the system all set up.

It is a slow enough bike so that my wife won't panic. And fast enough with the motor so I can actually get somewhere while it's still the same day. I am going to continue testing even though I don't have the gear range yet. With the one medium gear (I figure it is about second gear) I can do some range tests.

 

[deacon]

After the trailer rebuild and the new lock up for the friction drive, I took this bike out for a test run today. Three miles while I tried to learn how to ride it again. Every time I make even a small change I have to relearn how to manage the system. It isn't difficult it just changes.

So I left the driveway and had a bit of trouble getting it moving as I wanted. It did however eventually recover or maybe I recovered. I knew that it was chilly so I had dressed accordingly. What I did not realize was how windy it was. It was a cold wind that blue me around. First the wind came from the side and that wasn't too bad. Then the wind blew into my face and that was miserable. My hands (without my good ski gloves) got painfully cold. Lesson learned, as I sat in the Rite Aid Drugstore parking lot with my hands inside my jeans pocket. Don't go out without at least my wool gloves in the coat pocket.

Enough of that this is about pedal assist. There are three stages of pedal assist at the moment.

1...Pedal pulling the trailer with about thirty pounds of batteries WITH THE MOTOR OFF THE TIRE... that is the preferable way to go of course... at the moment with only one gear that is best with a downhill slope or at least level ground.

2... Pedal with the motor engaged and power on... this is good for steep hills, and spots where I just get out of breath. The pump isn't what it used to be.

3... Motor only at the beginning of a slight hill (One that is too much for the one gear to pedal alone) when the motor is engaged the free wheel device will not catch... so it is motor only at that point until the motor goes under a heavier load and slowing the bike to the point that I can pedal.

I am hopeful that when the new bike arrives in two weeks I can go with a total pedal or pedal assist. I would like to avoid the motor only part of the ride. I am fairly confident that it will add significantly to the range and the workout effect as well.

I did go three miles under very different conditions. I went slightly up hill for about a mile as I traveled along an old wagon road from colonial times. It became a major artery several years ago, but lost favor to roads that could be widened to four or six lanes. The road in front of my house had far too many houses that would have had to be bought and then demolished. There were other easier roads even though they were steeper not having been built for horses to pull wagons over. The grade has to be controlled for that.

Then I hit main street which is one long slow decline for a mile. That I could ride with no power at all. I hardly even pedaled but I did freeze as that wind blew in my face. After that road I hit that modern road I was telling you about. It was a fifty yards of rapid decline which was fun I admit. At the bottom of the hill there was a even more steep uphill climb which the motor and pedal assist did quite well. Then a nice long decline which was again fun being pushed along by thirty pounds of trailer as I was. At the bottom of that one I allowed the bike to slow significantly before I engaged the already powered up motor. I learned my lesson from dropping an idling big gas motor on a wheel turning at about twenty five mph.

That was the beginning of bike killer hill. I say that because it is one long steep mutha. My gas bikes bog down there and of course this pedal assist did as well. I pedaled hard and wished for a bike with at least one lower gear. but I made it fine.

when I got home I wasn't dead tired but I knew that I had done some heavy breathing. I also knew I could get to home depot for nuts and bolts, to the grocery store for ice cream, and to several restaurants so the bike is a success already and can only get better from this point on. The batteries had lots of power left as well.

 

[Ibedayank]

A sla car/motorcycle battery was never designed for deep discharge tell almost dead before recharging. but are designed to put out 200amps or more discharge for a for a few seconds then be recharged right away. to use them as a deepcell damages the battery.

Deepcell Battery is designed to have a small output current discharge over a longer period of time and then be slowly recharged. To draw 200 amps at once will damage this style of battery. Sla deepcells are not to be discharged to over 1/2 of a full charge as this shortens the life of the battery