The hybrid battery test reports ongoing..

[deacon]

today I rode the bike twice.. Once for day in the life thread but later I wanted to go buy some plastic battery holders. Not the small kind I mean the dish pan size, so I left the nimh pack behind so I would have room for the dish pans in my trailer. The bike did fine but there seemed to be a little something missing. I put it up bike killer hill and it climbed it but still seemed just a little off. I got my first real feeling that all was not well, when I started up the long slow hill for home. The bike made it but there was a definite slowing down and sag in the battery output. That doesn't happen with the combined packs. So maybe something is going on here. It will take a lot more rides to know for sure.

 

[deacon]

Just stopped by to give you the latest information. You can run a cheap aa nimh battery co mingled with an sla battery after all. The trick it to be sure the cheap aa nimh is at least as strong as the controller is pulling ah wise. If you don't the batteries will melt down. Those cheapo batteries on ebay are rated way too high. I rated them at 1.5 ah and then set twenty 12v strings to make a battery. They did not over heat and they gave me almost the same power as an straight sla battery. So far I have run one battery mixed with two sla batteries. I have the bike ready to run two nimh batteries with one sla now. I haven't ridden it yet. I'm waiting for the batteries to level out after a charge.

On this I jacked the size of the batteries up to about 35 amp hours figuring it at 1.5 am per battery. If this rides the same as it did with two sla batteries then there is no reason to think that the complete cheapo nimh pack wont work.,

The trick is that it isn't cheap at all. However if you are careful I think you can run it without a bms. I also know you can replace batteries one at a time. I mean one aa battery cell at a time. You need patience and not mind playing with them but in my case I have lots of time on my hands.

 

[deacon]

What I forgot to mention is that this will allow you to add one nimh to your pack to replace a single battery. Cuts down on the initial outlay of cash.

 

[deacon]

since I just ordered three new 12v 12ah sla batteries, I decided to break the nimh battery pack down to try that as well. I made two 12v 12ah nimh packs from the last incarnation of the sla pack I had. I did not expect much from them actually, but I didn't much care if I burned them up either.

So what happened you asked. Well for starters they didn't burn up, even when I paired them with my old 17ah battery pack. They seemed to drain independently of what the sla pack did

My first test was with the curry chain drive. I ran it what I think is about four miles and came in with plenty left on both sets of batteries. I hooked the batteries up to charge for a bit then took off again. I rode the friction drive over the same track, but I think the sla pack didn't get enough charge. It began to sag on he last mile, but it was still very usable. I checked it when I got home and the nimh pack was almost exactly what it had been with the other bike over a similar distance. The sla pack was down much lower.

I think this might just tell me that they are discharging independently of each other. Probably because they are piggy backed. not wired into the same strings. Oh yeah I also started off with the sla pack not connected and the 12v 12ah pack pulled as good as it had at 24ah so one of my theories was wrong. I theorized that if I added more batteries it would discharge a higher amperage. That does not seem to be the case at all. Even though it would seem logical. I think what the problem seems to be is that the batteries will give x amount of energy and not a bit more. less yes but not more. Where as sla will give you all they have up to the point of draining in two minutes if you can pull that much out of them. These, I think, would put out less energy but over a longer time. I know the bike runs stronger when it first pulls out why I'm not sure but it does sag when the sla pack drains. So more testing is in order.