Ryobi lithium Ion to power trike

[caykroyd]

I just ordered a wilderness BL-36 conversion kit. I want to use (2) Ryobi Lithium Ion 18V batteries in series to power it. I only need to go about 3 miles round trip. The batteries are rated at 2.4ah. Will this work? Will I destroy my battery life. Since I also use the batteries for my power tools, I don't want to ruin them, wanted to try and "multi-task" them. If it will be a problem, I will go a different route for the batteries, but thought it'd be fun to use the Ryobis.

Thanks for the help.

 

[dogman dan]

I think you may be pulling 20 amps at times with a bl36, so that's a lot from a couple tool packs. When I tried a similar thing with a pair of 24v drill packs (nimh) in paralell, they got really hot, and discharged in less than a mile. Those ones were pulling as much a 10 amps each, and that was too much for em, so I stopped that right away.

What you are planning, is a series connection, so each pack will pull 20 amps. I bet they don't last like that. Most folks using a tool battery like that are using a lot more than two at a time, many use 6 or 8 or more. For higher discharge rates, and still a very small, inexpensive battery, look into lipo batteries for RC hobby helicopters and such. Get a fireproof bag too, for charging, and to carry em on the bike. Some folks are getting real good results from those, and the prices are getting pretty low. Look for lipo or lipoly threads to learn more. Of course the sla's that come with the kit, ridden 3 miles a day, could last for several years if you allways charge right away.

 

[caykroyd]

Thanks for the info. I opted not to get the Lead acid, because I either want to do tool batteries or now look into the RC hobby batteries. I also won't be riding the bike everyday. Once a week at most. This just looks to be a fun project for me. If the Ryobi's won't go far distances, it is fine. 1-2 miles would be fine, but I don't want to damage the batteries. Do you think it can damage them or start a fire, or is it just a matter of them draining fast.

I just need to keep up with my wife. she's got 3-speed and 26" tires. I have a 24" single speed trike.

Thanks for the help.

 

[morph999]

there's a guy on here who tried using just one 36v tool battery and it didn't work out.

 

[pwbset]

When I first built my first prototype bike last summer I ran it with 2 Ryobi 18v Nicad packs in series. It punished those poor little batts, but I did get around 1-2mi range for a week or two. I'm convinced I probably cut the overall capacity in half or worse. :lol: I would recommend 4 packs in a 2s2p configuration at the very least, but your lithium packs may have high-rate cells in them that can stand the abuse better. If they are 18650 emoli cells for example you might not hurt them so bad at 8-10C if there is an internal LVC cutoff anyway. Good luck! Fun, fun!

 

[caykroyd]

Thanks for the replies. I've decided I'm gonna give it a try. I'll let you know how it works out. Worst case is I kill the life of the batteries (or set myself on fire). It looks like this stuff can get addictive, so I'll prepare my wife with the time and money that will be spent

 

[wasp]

if your in canada go to ct and check out thier yardworks 20v limn bats at 6ah each for 119 each
i ran 2 of these last year for thousands of km and they rock each bat has it's own built in lvc
that will shut it down at 15v also 31amps each and a 1 year warrenty

 

[dogman dan]

Good luck, if you ruin a battery, you can still hang on to it, and use the cells in it to build a pack later. You could try paralelling the lithium with some cheaper batteries like nicad.

 

[etard]

Well technically, if you ruin a battery you can take it back under warranty with certain brands. Why not get the Bosch 36 volt batteries? You can buy those on ebay shipped for under $50 each, I am sure this is way cheaper than the Ryobi's which are not going to be as good as the Emoli's in the Bosch toolpack. The Bosch will do 40 amp each.

But, If you want a high C discharge battery, just get 2 RC Lipo 22.2 volt battery, that way you can run them at 48 volt, which the Wilderness Energy controller can handle without any mods.

 

[theyerb]

there's a guy on here who tried using just one 36v tool battery and it didn't work out.

That was me I bought another Bosch BAT836 36v pack and now have two of them in parallel. They work like a charm Highly recommended and they get me about 6 miles on a charge. Best yet, they are only $46 shipped from ebay.

 

[caykroyd]

Since I have some Ryobis in hand, I want to try them first. If I don't get the desired results, I will switch to the Bosch. It's weird how the better Bosch batteries are cheaper than Ryobi's. Oh well.

 

[theyerb]

Good policy. I little experimentation goes a long way. From my experience, I don't think the Ryobis will have nearly enough amperage to power the kit. A low powered 36v kit should take about 23 amps (at least, that's what my controller pulls), whereas the Ryobis probably push less than 20 when in the series configuration. You will probably get "intermittent" power: it will work for 5 seconds, then cut out for a second... Let us know how they work.

 

[caykroyd]

Got the bike hooked up. It was running pretty good until the wheel torqued off the fork. I don't think I had the wheel tightened enough. At least I hope that was the problem. Anyway I bent the rim so it's already out of commission. I'm taking it in to get it fixed. Is there anything else I need to be careful of aside from tightening the wheel? Is it possible to be overtightened?

Once, I get it back together, I'll update you with how far I can go on a charge.

Thanks for the help.

 

[etard]

Welcome to the world of front wheel hub motors. It's unbelievable that they still sell these things despite almost everyone that has flew over the handlebars because of.......

LOOSE AXLE NUTS!!!

I have done this 3 times myself. Bike is still out of commission.

 

[dogman dan]

Yeah the learning curve is steep on those things. Bummer, but you sure aren't alone, my first ride went 1/2 mile.

here's what to look for on the next try.

1 if the fork got damaged or bent any this time, forget that fork. You will need a replacement. so look for evidence that the dropouts have spread open.

2 If the forks are ok, then look for any kind of deviation from a big flat surface. some forks have a little bent tab, others have a little cup that fits a quick release. Anything that allows an air space under the big electric hub washers will cause the hub nuts to loosen as the washers slowly deform into the space.

3 Get a washer with a big hole and a small outer diameter, or file away proturberances, or best yet, get a bike or fork that has a big flat steel dropout.

4 Install the hub as follows. Gently torque the nuts to a snug but not very tight fit. Mabye 5-10 ft pounds. Use a fairly short handle wrench, because you can easily strip an axle. Look for any indication that the fit isn't perfect. If the hub wants to squirt out of the dropout as you tighten it, its a HUGE RED FLAG WARNING.

5 Wait 5 minuites, even with a good fit, the washers need a bit of time to slowly begin to deform just a hair and reach a perfect fit. Then tighten a bit more, this time pretty tight, but not with all your strength, especially if you have done a lot of work that gave you a strong arm. Watch for movement, be sure the pressure is not slowly spreading the dropouts. Wait 15 minuites, about the time it takes to wire your controller and tie down the wires. Then do a short no load test, just a few seconds to see if everything is straight and no unforseen problems exist when the wheel is spun.

6 One more time, by now the washers are settled in, and the fork isn't bending. Usually you can get just one more tiny bit tighter on the nuts without stripping an axle with too much torque. At no time is this as tight as you would do a lug nut, but you want all the tightness you can get without putting a big long handle wrench and ripping the threads apart with it. The idea is to use a relatively light hand, but still get all you can with that.

At this point, if no warning signs are seen, you can be pretty confident that the dropouts are good enough, and the motor won't spin with normal loads on it, like 36v full throttle. Check the nuts again after the first ride, sometimes another hair of tightening is possible after the first ride. Installed this way, I have had hubs go 1500 miles with no loosening of the nuts

Good Luck and be carefull, see what is happening instead of merely looking.

 

[caykroyd]

Ok. Trike is up and running. Got the wheel straightened and wired everything up. Tightened the wheel on the fork properly this time.

Once its going, no cutouts. But occasionally if I release throttle then engage again, the motor sputters and doesn't spin. If I release for a few seconds, then it runs good again. I'm guessing this means the battery is cutting out in between throttles. But it doesn't seem to cutout during a continuous throttle.

I haven't tested distance yet, but I will update on that.

I'm guessing these batts won't cut it for a normal setup, but since I go about 2 miles round trip to the grocery store or out for dinner, I don't need much more. I'll post some pics. shortly for anyone that's interested.

 

[theyerb]

That's great! I think the Ryobis surpassed our expectations, even if they don't perform that great. I'm surprised they can run without cutting out. I'd love to see some pics if you them.

 

[dogman dan]

Yay! You are nearly there, and are there, if you can live with the throttle issue. You get a spike of amps when getting on the throttle, so you can learn to use it more smoothly I'm sure.

 

[caykroyd]

Well, the ryobis went about 0.75 miles with no pedaling. Let the bike sit for 10-15mins. with controller still on. The batteries still had the green light (full charge) indicator, but got the sputtering motor again.

So I'm not sure if the batteries were too low based on distance or if the controller turned on but idle was the problem. The research goes on.....

 

[dogman dan]

Your distance is not far off from what I got from 2 tool pack batteries. The high rate of discharge results in less avaliable amp hours, it can happen even with lithium. It's worse with sla's, but if you add 2 more tool packs, you will likely get a lot more distance. I am seeing the same effect with some nicad I just bought from ebikes-ca. One pack by itself gets hot fast, but two stays very cool. Lowering the c rate really helps batteries.

 

[caykroyd]

I got 1.6 miles with partial pedaling. Unplugged batteries for about 3 hours without charging. Rode for about 0.7 miles without pedaling. where the last 0.25 miles was full throttle....Waited 10 seconds (for my wife to catch up ). And had to pedal the rest of the way home. Full throttle really kills these batteries. I'm sure I could've made it all the way home if I didn't go full throttle.

Overall, I'm very happy with the results.

 

[rbelisle1]

if your running one of the new brushless 36 volt wilderness energy hubs and the no sensor controller, the controller can pull 50 amps, not 20... According to my very old school, not calibrated analog amp meter, 50amps is max and top speed crusing is about 10 amps... thats a lot of amps to pull..

I run three 12 volt 18ah agm lead batteries and I have about a 15 mile range. My normal trip is to work and is about 7.5 miles. I chewed through the 12ah agms in about 400 miles. The new batteries failed within about 2 weeks and were replace under warranty. The new new batteries have about 100 miles on them and still going strong...

bob in phx.

 

[dogman dan]

yeah, the same reason I stopped using the 24v nicad tool batteries. I was series connecting two of them for 48v, and figured that since they got hot enough to be hard to hold onto, it must be a bad thing. 4 tool packs to run a bike seems to be about the minimum. Thanks for the amp measurements. The we controller is supposed to be 20 amp, but I knew it had to be able to pull a much bigger spike than that! Since you sometimes see it called a 50 amp, I figured a 50 amp spike was a possibility. I am a bit suprised that it cruises at 10 amps though, I expected it to be more like 13-16 amps full throttle on flat ground.

 

[caykroyd]

Today I made it about 4 miles. I accidentally throttle from a stop and then the batteries cut out. Waited about 5 minutes and batteries came back to life. I think there might be some battery management system within the battery. I think can probably push it another 0.5-1 mile more.

 

[dogman dan]

There is a little bms inside. I bet you are learning to hypermile nice with that set up.