The hybrid battery test reports ongoing..

[deacon]

Based on my usage of the hybrid battery pack I have a prediction. I predict that when the nimh battery pack reaches 25ah it will coast on that pack alone.

I am going to lower the wattage of the motor on the rhino so it might happen sooner. I am basing that number on the fact that the motor pulls 25 amps just to run. Pulls 35 to climb hills ect.

Running the 24v sla pack and the 35v nimh together convinced me that the draw down of the packs is based as much on the type battery as on the controller. It pulled more from the nimh when it was the dominant power source. I think that at operating amp use, it will draw equally from the two packs.

That is my swag for the day. For those of you new to the thread swag= scientific wild a** guess

 

[zabac70]

Well , every great discovery and break trough started with a sentence: What if...?"

 

[deacon]

Is that like my daughter saying, what if you stopped all this and just saved the money. If i did that she would have a larger estate and much sooner as well.

 

[OzzyU812]

how many keyboards do you wear out a week?

 

[deacon]

so far this year Im on the same one but you can't read teh letters over a lot of the keys. And that is the truth. I have way too much spare time these days. My wife complains that I work too much in the shop and yet I have time to do all this writing. Way Way too much time.

 

[OzzyU812]

mine is 8yrs old and counting.......

 

[zabac70]

Diluted clear epoxy resin over keys (applied with brush-two thin layers) and you are good to go for some decades (till your fingers are worn out)...
...Man , I'm full of useless knowledge...

 

[deacon]

I once, long ago and far away, was an insurance investigator, right after my cop days, and the one thing I learned from those years is that NO INFORMATION IS TRULY USELESS, just maybe useless today.

 

[deacon]

As you might know i down graded the motor on the rhino bike. I went down from 600watts at 24v to 350 watts at 24 v. I ran them both at 36v so they are considereably more powerful than the stock.

So I had tested the 600 watt motor and it would not cruise at all solely on the nimh pack. I made the same test today with the 350 motor. It does indeed cruise If it goes down an incline it will pick up speed but it still doesn't have the guts of the sla pack. I think the pack is now 18ah more or less. I also think they rate the batteries way to generously. It is quite possible that it is really less than 15ah. I think this will eventually work though.

 

[deacon]

There is something fundamentally wrong with this project. If I run the test with the sla and nimh on all the time there is very very little draw from the nimh pack. If I flit the sla in and out ie nimh only on the flats, the draw is horrific. I think the battery pack is way over rated ah wise, If that is truly the case, the cost of the nimh diy pack would be as much or more than the lithium packs.

Since I have a 24v controller on the rhino bike, i am going to recharge the nimh pack and set it for 24v and see just how it performs and what the current draw down is, that should give me some indication of the amps in the batteries.

 

[deacon]

I have found out what if not why the nimh is doing. More ah hasn't had the desired effect or much of any effect at all. So I tried to increase the voltage and that did it. Still the batteries won't last long spread that thin.

What I have decided to try next is to use the nimh as a reserve. When sla goes flat, long before the bike dies, they just begin to perform lousy. I already have the rhino set up with a on off switch which I used to kick the sla in and out,. I think I am going to try putting the nimh on that circuit and kick it in when the bike's performance goes down. A fresh shot of amps as it were,

I will give this a shot tomorrow if it doesn't rain me out. Since it is just a test, I'm going to use just the c cells. It will be easier to wire them up for the test. It doesn't matter how long they last it is more about will the added cells help the tired batteries. If it helps then I will rewire the whole pack for it.

 

[deacon]

I ran the new 350 watt rhino (@24v) at 36v today and realize it is the right size for me. It pulls the hills when i need it to. It runs about as fast as I want to go on the flat so it is just a good size for me. It is also better on battery consumption that then 600watts @24v motor is.

The test was also to run the batteries until they started to go flat then kick in the nimh pack and see what happened. The nimh pack kept the motor running at the flat rate., It didnt help at all except to prolong the agon.

However something I learned from two different previous experiments has given me an idea, I learned that when you piggy back different voltage packs you get a voltage somewhere in between. Depending I think on the condition of the packs at the time. Probably has some amps thing thrown in there.

I also learned that if I jack the voltage up to 48 the bike ran much better. So....I am going to repeat todays experiment tomorrow but with a 48v back up pack. When the sla pack goes flat it will be about 37v If i throw in 50 fresh volts I should get something like 40-44 volts. That should be enough to revive the battery until the nimh runs low as well.

I am looking forward to this test. I would run it now but I need to recharge the old 12ah pack so that I can run it down again. I will probably burn up the controller since it is just 24v lol. Still it is worth a shot. The nimh pack just doesn't seem very hot. It might not burn up the controller just have to experiment to see.

 

[deacon]

Got it in my head and couldn't wait so I tried it. Success at last. Not perfect mind you, but at 48v piggy backed onto the almost dead 36v battery pack it picked the speed and power back up. Not quite a 100% but a respectable 75 to 80%. It would be enough to add several more miles onto the bikes usable range. I am sorely tempted to strip the controller and throttle off the rhino and run the nimh at 48v to see how it does. I have no idea what the 24v controller would do with the pure 48v nimh pack. I also didn't check the battery drain in the nimh yet. I thought I would give it a chance to rest first.

Since the nimh pack I have does not jerk the chain on the chain drive bike, I could easily use it with no controller on the rhino I believe, even if I went up to 60v. I will have to do more testing since I am now pretty sure this can be done but it may wind up being prohibitively expensive.

It runs like it is putting the equivalent of 37 volts maybe. I have no idea why it has no umph it just doesn't It took more volts to make it run and I'm not even sure the controller recognizes the extra volts they are so wimpy.

 

[deacon]

So I had this 48v nimh pack set up and decided to piggy back it onto the old wornout 12ah pack from last year, I went about five miles up and down my test track complete with one moderate hill. one long incline and a couple of smaller hills. The bike started to run like pig so I came home and found one sla batter reading 10.9 v bad bad bad. Twenty minutes later each of the sla read 12.8.. At 12.8 they should have had more power left, so obviously one of the batteries has problem under load. I tried to stress the batteries one at a time but I lost patience. Tomorrow I will run that pack to the park I think that should bring it home stressed,

I have a trailer finished for the chain drive, I might change everything over to it and give it a whirl for a while. I'm not thrilled with the way the rhino ran today on the trip to the hardware store. I might just go back to the bigger motor after all. The new motor does not have a clutch so it has constant connection to the bike wheel. It makes a really nasty grinding sound.

It doesn't sound too bad unless I'm on the bike. I'm afraid that it might not be the motor but might be the bike wheel. I need to change the tire on that bike tomorrow I might see if there is anything wrong with the bike wheel. if i can.

 

[deacon]

I ran two tests on the hybrid battery packs. Here is what I found weird but true. There was one minor difference I ran run one when the sun was shinning and there were raindrops falling on my head in test two so I pushed the bike harder I'm sure.

test one just sla batteries. Right off the charger it read 41.0 v after the two mile run it read 39.7 1.3v use.

Test two sla pack and piggy back nimh pack. off the charger at 40.7 out and 39.2 in or 1.5v used. I did push the bike harder as I said above. I would expect the drain to me more but the piggy back didn't seem to do anything. however there was a fairly equal drop in the voltage of the nimh. So something was going on with it.

The test track is about 2.2 miles of various geography.. Some hills, some flat areas just generally what it is like here....

I have to change the rear tire on the bike then I will be repeating this test off and on over the next couple of days to try to determine if this is a viable use of the nimh pack. Oh yeah the nimh pack was also 36v

I want to make a complete test under the same conditions. Then move on to changing the nimh pack around some.

for info.. The sla pack is about 8 months old 17ah batteries three of them.
The nimh is about the same according to the mfg of the batteries more likely it is only ten ah.

 

[deacon]

I have given up on a nimh pack. I could probably buy some very expensive nimh batteries and make a decent pack but with the cheap easily available batteries on ebay, it just doesn't have the umph for a bike. It is like riding a bike with a governor that has gone crazy. That's okay though. I learned something about batteries, all batteries are not created equal. I'm going to test these seriously now as a hybrid system. I will run them with my sla batteries standard. Well at least as much as i can.

So today I'm going to do a trail ride test. I try to run the trail with as little battery assist as possible. Get a little extra exercise. I am going to run down to the trail an then on it with the nimh pack only if possible then when I get ready to come home on the roads, I will unplug it and plug up the sla pack. when I get home I can read both to see what happened.

Im off to test it now.

 

[deacon]

Well I got about two miles before I got tired of pedal assist. I put the sla pack in and ran it slow and still pedaled but it took the bite off the hills the nimh couldn't do that.

As one would expect the nimh pack had more volts drawn from it. I have a feeling looking back that there batteries are way, way over reated. Maybe for a thousand dollars you could string together enough of these toy batteries to have a pack. I have wasted enough money on it. However as I said I am going to find a way to use them on my ebike.

I need to do documented controlled tests tomorrow. I am still waiting for the controller for the chain drive. The order I submitted did not go through. I resubmitted it to tomorrow or the next day I should have that bike ready to go.

I got the last of my nimh batteries today and they really are the last of them for me. So lets see how I can use them.

 

[deacon]

It is going to be very difficult to quantify the hybrid pack. Everything is so different each time I take the bike out. Generally speaking I think it does some better range wise. {pwer wise it seems to be the same.

the nimh pack dropped more volts when I first came in but it went back up to way past the sla pack. However it did not share volts with the sla pack even though they were in parallel. It is going to take a lot more use to decide what is going on.

Frankly I'm wondering how much the ratings of the batteries are off. If the 17ah pack reads 13.1 after a four mile ride, and the (mfg desig) 30ah pack reads 13.5 maybe its something else going on here. Oh well I'm going to use the pack everyday and see what happens.

 

[deacon]

One of you guys who is smarter than me explain this please. The hybrid system suddenly took off. I rode the bike yesterday with it and saw a change in the consumption but was afraid to be too upbeat. The pure nimh pack has let me down a couple of times. Today I rode the bike with the hybrid pack to the mall. It is a mile there and a mile back. When I got home I separated the packs, but didn't have a chance to measure them for about half an hour. When I did I was a bit shocked.

On that same ride with the sla pack alone the batteries are always down .2/.4 volts at least. This time it was almost exactly the same as when I left the house. It showed almost no drop in voltage. The nimh pack was down about .1 volt. I did not run the bike in economy mode either. I ran it wide open most of the time. It performed as it always does.

I'm pleased of course, I just don't understand it. I still don't have the chain drive up yet, so this was on the rhino drive which may not be as efficient as the chain drive. This may or may not be good news for those of us who have older sla battery packs. To be able to extend the life of the ones I have and then to purchase smaller sla packs in the future would be kinda nice for me at least. They say the nimh can be charged a 1000 times that would definitely be nice.

We will have to wait and see....

 

[deacon]

So I decided that it was time to test the batteries again. I have a few more coming but I have enough to get a full load at 24v. Now knew that the bike was going to run not so great. It was a test of range not performance. I rode the bike farther than I have ever ridden it before. I came in with 12.97v to 12.95 volts on the batteries both sla and nimh packs. So I went twice as far as the sla pack would have taken me and I still came in with enough power to have gone farther.

I have way too much money invested in this to make it feasible, but it is a way for me to use the batteries and keep testing them. With the batteries I have coming in I should be able to use them in the 36v configuration.