I love This new baTTery. IT works greaT. 10lbs. It makes a nice barbell. Its only 3"w.
Of course I'm sure it has some voltage sag at full throttle. So it goes faster on a higher voltage because I don't have to demand as many amps for my riding style. And of course voltage decreases through the time of the discharge; so that, i lose 10mph of top speed should I ride in the later half of discharge time period.
The really odd thing for me is a) how to tell when battery is fully charged. What is the best method to charge? Here are some of my observations. I have no prior hands-on experience with this type battery.
Here are some of my nimh observationS:
these R 4 the sub-c cells purchased as 6-cell configuration for model rc vehicles.
http://tinyurl.com/4zpc2sb
with these chargers--I purchased 8 of these.
http://tinyurl.com/489wbw4
I bought some other chinese cells from hong kong before these; but, it will take some time to get my order straightened out. The above cells and chargers are delivered in 3 days.
So the hong kong cells seemed to be charged already, and they didn't take much of a charge, and they didn't put out the claimed 6.8ah, more like 2ah, so that the first time I ran them, they ran out of juice, so that I had to finish the trip, so I kept the power on. On a load test at my destination, I was able to drop the cells ' voltage to .6 volts or so. After that the battery took a good charge (3ah or so). I did run this same battery later, and it went easily 6 miles.
The point of the above is that the later 10-c cells I bought arrived differently. They had about 7.2v or less. They took a big (3ah) charge right away. And they performed well the first time out, which brought to mind that perhaps these cells were "zapped" or something.
The chargers all work. But many times one will trun green prematurely. But usually on the low amp setting. 4 of the chargers have .7amp-1.5amp switch. The newer ones have 1amp=1.5amp. On the 1.5amp setting, the batteries will get pretty hot when charging completed. I use the 4 with the 1amp setting to charge at work. The last couple of days, they were not unplugged after the lights turned green, so that they stayed connected with power on for 5-6 hours after charging completed. I keep getting the thought that the chargers are trickle charging in some way. They are "tenergy" brand chargers. The reason I say this is that when I unplug the battery hours later, it is just slightly warm, which indicates charging. The voltage was 97.5v with chargers connected and green light. after 3 mile discharge, battery at 89.9v, then sit for an hour, up to 91.9v.
Now contrast this to what I did on my trip to work. I charged at 1.5amps the night before for about 1.75 hrs tops. The batteries were hot. Then unplug chargers. In morning, voltage at about 97.5v. I pluged into chargers at 1.5amps for less than 15 mins. Now voltage holding at 102.5 on cold battery. I worry again about blowing my 100v 5yr old controller. I don't have much choice, so I connect and go. No problem, only scorching performance with close to 40mph speed.
I have noticed that when I charged my batteries at work in this manner ( 2 charges), after discharge, voltage finishes at above 92. And then the oddest thing, which I have noticed more than once, is that after running the battery after the two step charge, when I charge it, charging is finished in an hour or less. This happened the other day. I got home. The battery was still warm from the discharge (it gets worked really hard). But tonight I want to charge at the lower rate, as this is supposed to be better (less damaging?) to the battery. So I plug in at .7amps, and chargers turn green in 55 minutes. So then I think I charged them at the higher rate in the next morning, but the chargers still turn green. So there appears some sort of weird difference of voltage measurement and charge acceptance, and extremely likely, total ah capacity,, relating to the temperature of the battery. When they get heated, voltage is depressed, and the heating from charging will also cause a drop in capacity during the time the battery is hot. Then when cool, more capacity can be added, with an accompanying increase in voltage. Of course all this is based on voltage measurement as a measure of capacity at any given moment. I'm not even sure of this first precept in relation to nimh. From what I've read and heard, as this battery finishes its charge, its voltage decreases. So then does this mean that the voltage will rise as it is discharged??? I haven't noticed or checked for that scenario. Maybe the reason the voltage goes down is because the heat goes up. It appears they go hand in hand.
So now the only logical following next course of action for performance increase of my power cell is to put it in the fridge. I was going to say the freezer, but I will try the fridge first and see what happens...
Does this sound right? Anyone want to share some nimh wisdom?
No matter. I am very thankful for my battery performance current LY.
I did desire a single 100v charger. I connected 2 ping chargers in series with another 12v charger. Now I have 2 chargers instead of 3...Don't NO until U try.
96.5V on a 100V controller does not leave any headroom for inductive switching spikes, gravity tides, moon phase modulation, etc to work its evil ways.
