The hybrid battery test reports ongoing..

So I finally got everything in place to test the Sealed lead acid and NiMH battery packs together.

My particular Nkpk (nimh pack) shows a charge voltage of 13.5o or so after resting overnight. I put together and 18ah pack comprised of (3) 12v 18ah batteries. Each battery is made up of 2 sub batteries make up of ten c cell nimh batteries. Each of the 12v 18ah batteries is actually 20 c cells. ten in series and then two sets of the ten in parallel. Then of course 3 of the 12v 18ah batteries are strung in series to make 36v.

That battery pack was connected in parallel with a very old 12ah SLA 36v pack (slak). It left the house at approx the same voltage as the NKPK.

I chose the old 12ah pack to start my test because it had done two miles before it had a sever drop in voltage just s few days ago. So with everything set and a few false starts to get the wires tight, (Waiting for connectors from china to make a more solid wiring pack) I was off for my test.

I decided to take the exact route where the sla batteries failed at two miles. The first thing I noticed was that the bike had more torque than usual. I could climb hills with throtte way under the wot position I had been using. The test bike has no suspension, I was also pulling a trailer so I didn't try a speed test. I did do all the speed I wanted and there was plenty of throttle left for increases on the hills.

When I hit the two mile mark the battery pack was still running great so I swung the bike onto my test track. After another mile the battery was till in good shape, so I swung it onto the second mile of the test track. At the four mile mark (Double the distance of the year old slak) the bike was still running strong but a wire came loose so I took it home. The slak read 13v. It still had at least another mile in it. The NKPK had 13.25v plenty of power to boost the slak another mile at least possibly more.

Now this thing needs a lot more testing but at this moment I have to admit I like it, I didn't even use the other 10ah NKPK pack. If these finding hold up, I for sure will not be buying 17ah or 30ah sla batteries. I wonder what a 7ah slak would do with the 27ah NKPK. Now wouldn't that just be groovy.

PS when the wire got loose on the slak I pulled the bike in with the power from the NKPK only. It ran like a pig but it was helpful with the pedaling. The test bike has the chain ring from a 16 bike so without the NKPK there would have been a whole lot of pedaling required.

I just realized how hard it is going to be to generalize my information. I ride the most inefficient drive system known to man. Friction drive... I have it set up on bicycles I built from junk parts. I'm running the test with year old slak and home made NKPK hybrids. How in the world do you take this data and apply it to a high performance brushless hub drive system. I would say that the best results I get, will be less than the minimum you would get on any factory bike.

If this afternoon's results hold up to the morning ones I should have the beginning of some real answers. I can maybe work out a rough percentage of increase range that might hold true for you.

This afternoon I will be running a 10ah NKPK with the same old 12ah slak. This would be comparable to you building the 36v 9ah set you could build for 60 bucks to add to your existing battery set up. It might give you some idea of the range increase with a battery pack you could almost fit in your pocket.

If I don't have a significant increase over the slak, I will just add this ten hours to my 18ah pack that I know gives a huge increase. I'm just testing now to see what the difference between the two NKPKs is.

Today's test is to ride to the lake and back. It isn't all that far about six miles up and down some nasty hills. I have ridden it with my 17ah slak and it come in on a wing and a prayer and me pedaling my butt off.

I am taking the sla pack full and the so called 17ah nkpk full as well. I am not taking the so called 10ah nkpk because it has to be charged up seperately. There is a lot wrong with it. That is the pack made from all those AA batteries. The c cells are much easier to keep in line.

So I'll let you know how that works out later in the day.

da test didn't go too well. The wheel on the trailer decided to go 45 degrees out on me. I have to baby the bike and pull the trailer along at a crawl,. So I'll do it again later.

The nimh pack did nothing at all on the long ride to the lake. It helped with the other rides so I had a problem trying to figure out what happened. I think this is what it was. The bike called for max output of energy the while time. It is up and down very steep hills going out there. The nimh pack releases energey at a level amount. It couldn't replace the energy fast enough to make any difference.

The batteries read upon my return.. nimh 39.1
sla pack 37.8 a very wide difference. Not sure what it means but definitely not what I expected. If I had stopped and waited a while at the lake the batteries would have equaled out? I wonder...

always welcome new ideas I will take a look

It's possible that the nihm pack in parallel has a positive voltage effect since it finishes a volt or more higher than the sla. Maybe that is why the bike seems to run better but the pack is not strong enough to pull the bike by itself for some reason. Actually it will pull the bike, but is stumbles along like a pig trying to race a dog. Im hoping it will do better with the hub motor.

I took the new schwinn sissy rhino out for a spin. I have been hearing that i need to run the nkpk down so I took them along for a test as well. My plan was to not recharge them but to recharge the slak.

The course is mostly flat with one up hill down hill spot. Just your average high point trip. It's two miles almost exactly.

The pack came back with 40.2 volts on the nkpk and 39.? on the slak. Hardly anything to report there at all. However I did notice something different. I have previously commented that the bike seems to run better with the hybrid pack, I think now I know the difference. It accelerates as strong as before, but with no jerk at the start.

Those of you who ride bikes with chain drive and sla pack will know what I mean. When you throttle up a sla pack, it shoots a hot hit of current to the motor and the motor give a great jerk. It will sometimes throw a loose chain off the sprocket.

Well the hybrid pack does not do that at all. When you call for power it increases evenly. Not sure if that makes any difference but it does make the ride a little bit less stressful. The bike doesn't feel so squirrelly,

after two more miles (four miles total)

nkpk 39.8
slak 38.6
Now im going to let them rest and see if they will share energy. I am going to try this set one more time. At about 37.5 the sla pack is pretty much gone. I will bring in a old 12ah pack to put a few more miles on the nkpk pack. I have no idea what dead drain is for the nkpk. I
I think nkpk would be considered empty at 36v I'll try to get it down to that at least before I recharge.

If it doesn't rain again I might be able to get it down to that. By the way I am riding max drain not max life so I don't know if I could extend the range by pedaling more. I probably could on the hills by throttling back and doing a little assist.

I'm not positive this will actually work but I think I can use this most effectively like this. The nimh and possibly the litho packs are better cruiser packs than the sla by a long shot, but I just feel that the sla is the better hill climber and start off pack, My idea now is to rewire the bike so that the sla pack has an on off switch on it.

When I get enough ahs in the nimh pack, I will cruise with it. It does seem to last much longer. I can throw the switch and bring in the sla pack on the hills where the nimh pack turns to pig power. Then turn it off to conserve the sla pack. Using both sources of power I might get a better range. It might not be any cheaper than the litho pack to be honest, but I will have at least done it myself.

I'm thinking I'm going to need at least 25amps on the nimh pack. I have downgraded my appraisal of the nimh ah which were based on mfg/dealer info. Rather than their 25.5 (after the melt down) I think it is closer to 17ah. I have five more ah on order, so when it arrives I will rewire the switch into the bike. I expect that the needed sla might be less than ten ah it would vary with your topography.

Today I had a minor problem. I wasn't getting power to the Schwinn Rhino, so I had to test the circuit. In doing so I misplaced my forty amp fuse. When I got the problem fixed, I couldn't find the fuse, so I put in a 30 amp to test the bike. It did fine till it got to the corner where I made a right turn onto a minor incline. The fuse blew at that spot. That is also when I made a battery break through. I had been setting myself up for it by all the tests I had previously made.

I am now almost a hundred percent sure that the rhino motor which is 25 amps pulls 35 amps on start up and on hills. So, if the battery only puts out the C of 1 (in oher words only the amount of the amp hours) the batteries were not strong enough to pull even a minor hill. So the combo sla for the hills, and the nimh to push along on level ground (or even minor inclines where the bike has the speed to climb it with minor power) should work great.

I am going to need a battery pack with the same ah as the motor's basic rating. In my case 25ah. I can do that with this next battery load I think. Then I will wire the switch into the circuit for the sla pack.

One of the things that I learned from my previous hybrid test, which is going to prove important, is that I can leave the nimh batteries in the circuit and just switch the sla in and out. I will have to make tests to see how long the sla pack will hold up to determine what size sla would be best. I imagine it would depend on your area. I think a 12ah will be good for me but maybe not for rides like the lake ride which is almost all up and down big, big hills. If you live in a flat area you might just need a 7ah pack. If you like to pedal 24v might be enough for you.

This still needs a lot of testing, but I believe I am on the right track.

Also the litho pack will put out a higher rate on demand which is why they are usable in lower ah packs. However this nimh pack might get better range since you will not be draining the nimh pack more than its ah rating at any one time. It will take a larger pack though which might be a problem if you want to use nimh alone. I will be testing it both ways I'm sure.

The next battery increase should get it high enough for the hybrid to test out pretty well as stated above. The manufacturer has the pack as is rated at 25ah but i think it is more like 17. It is close now but the new set due in a few weeks will increase it to the tipping point I think.

In my last installment I stated that I thought that I had a breakthrough in how to use the battery packs. So not being able to wait, I wired the bike last night and then again today to make it work. AND IT DOES...

I need more nimh ah to make it work well, but the concept does work. As i stated in the nimh link, I think the ah is 17 which gives me piggy power. But if I get that up to the operating level of the motor 25a I think I will have a cruiser, but it won't really climb hills very well. The reason is that to climb a hill and start off the motor needs about 35amps. For that I have a second pack. It is sla and it is a monster on hills.

Here is what I previously learned that makes this possible.
1. I can run nimh and sla at the same time, but only in parallel. (series will burn them up) Both have to be full packa and wired separate from each other, but they will run side by side with no damage to either.

2. When running parallel the sla pack will empty at about the same rate whether the nihm pack is present or not. I think it is because my nimh pack puts out the same amps continually, which at the moment isn't enough to run the bike even on flat ground. That's why the range didn't go up very much. When the controller called for more amps, they flowed more easily from the sla pack so that is where they came from most often. It is also the reason the nimh pack came in with more voltage left than the sla pack.

So to increase the range of the Sla pack, I figure I need to remove it from the circuit until I need it to climb a hill or to start off. I wired the bike so that the nimh pack is always on, but the sla pack is switched. So here is what I hope the hybrid will do.

1. Start the bike off with the combo pack on. (I did this and there is good power)

2. Switch the sla pack off when the bike is moving along. (I did this and the bike indeed went to the nimh power supply alone. At the moment my nimh power supply is too low to drive the bike at more than walking speed, but it does work.)

3. On approaching a hill bring the sla pack back into the circuit. The effect is immediate and dramatic The bike will climb very well.

Since the sla battery pack is being used sparingly it should last longer. How much longer I expect will depend on your geography. I have two questions that need to be answered.

1. At what point is there enough amps to run the bike from the nimh.
2. What will the increase in range be and will it be worth the extra cost of the nimh pack.

Let us say you are running a currie 450watt motor at 24v You have an operating current need for 20amps probably. Just like me you may peak draw 30 to 35 amps. You only need those amps a few times a ride. Mostly you are going to need 20amps. If you were to run a 20amp nimh battery pack which will put out no more than 20amps no matter what. Then it would run about one hour or a little longer. Probably giving you 15 to 20 mile range (total swag) If your 7ah sla batteries would do twenty minutes but you are only going to use them half a dozen times for three minutes at a time you should be about right.

If you built your nimh battery from the most expensive cheap cells (yes I know it is a contradiction) you would have about 200 bucks in a 24v 20ah battery pack. Then add in fifty more for the sla 7ah set and you might have a long range battery somewhat cheaper than a litho. But best of all you could service it yourself. Replace a bad cell or a bad string.

I have to keep adding batteries before I can say for sure, but I'm pretty sure it will work just as I have outlined it.

The numbers on yesterdays hybrid test...

Remember I tried to use the underpowered batteries on the flat and the sla on the hills. I left the house with both battery packs about 13.5v more or less. The pack just by swag is about 17ah The sla an old 17ah pack. I ran the one mile multi terrain test track.

I let the pack rest over night then read the battery charge. sla 13.28 about a .25v drop in voltage. The nimh pack 12.89 about .6v drop in voltage. I am pretty sure that the sla pack was turned off last night so there would have been no co mingling of charge.

There is a significant difference in pack usage for sure. Still I have to remind myself that the nimh is way underpowered still. I wish now I had stayed with the AA batteries completely I could at least get some kind of idea what the pack really was ah wise. Those c cells are throwing a monkey wrench in the figures I'm sure. (monkey wrench = skewing)

I feel like the nimh pack needs to be 25ah since that is the normal draw of the motor. 35ah might just pull the hills I have no idea those are just two more examples of swag.

Using the 2500 aa battery one would need 300 just for the 25ah... best price I could fine was like 210 bucks for enough to build a 36v 25ah battery pack. I found that vinyl electrical tape works better than duct tape. The spring provides the needed tension on the connections. The battery pack is going to be considerably larger than the litho packs for sure. I have a couple of briefcases left from my working days, so I am going to probably have to move my pack to one of those.

If I went full nimh, I could probably wear a small backpack and just plug into bike lol... Now on a hub motor that would be stealth for sure. Wear black with a black cord.

I let

I agree on the c rating thing and checking on true amp hour rating to build from Zero. If I did that I might have found lithium just as cheap for the same thing. But I think I would still go with nimh for the ease of switching out cells.

I would like to find someone in town that could check the ah rating on the first pack that proves satisfactory. I really should buy an amp meter but I don't care about one that reads continuously just one I could take a reading on the pack before I left home.

I have used the 2500mah aa batteries and I think I like working with them. I have no idea what the c rating is but it must be just one. The whole pack is pretty much flat.

I have a spare motor just like the ones I run sitting around. Why can't I hook it up and just turn it on till the pack runs out to get a no load time rating for the pack. Then work from there.

thanks that what I needed to know at least I can get a baseline on it. How low can I drain the nimh cells volt wise before I damage them. If that is even a factor

the nimh pack is not up to the amp reserve that would allow it to run alone yet, but I ran it with the sla today. It drew about .1 volt in a mile The sla likewise drew dawn very little but I'm not convinced that one really helps the other all that much but it does something with the smaller battery pack. I just don't know yet.

todays test result part two...

I teamed a 24v sla pack up with the 36v nimh pack on that high amp draw motor. First I ran it with the 24v sla pack alone and it wouldn't get out of its own way even if I pedaled.

Then I came home and added the 36v nimh pack. The bike ran at 30v and ran pretty well. It still wouldn't climb the hills without pedal assist. However it wasn't required often or any real hard pedaling.

The really interesting part came when I read the batteries after the ride. The nimh was down 3/4 of a volt/ Which tells me that yes it was putting out power. Enough to make a difference that I could feel. Even though the batteries were close to the cut off point of the sla batteries, the weren't flat at all.

The sla batteries were down a 1/4 volt which tells me they were not working as hard as usual. So now I'm going to charge the nimh pack and let it rest until I can get more batteries into the pack. I am pretty sure that it just needs more punch now.

ps the batteries did not appear to heat at all.

pss I am finding all this fascinating... I just love puzzles

Those of you who have been around a while know that my threads are about entertainment more than any great truths, so don't go out and throw your money away just because something works for me.