Well guys here is my first post. I have been lurking this forum for a couple weeks now trying to figure out what i can do about my stealth 1000 issues. When i snagged it from my little bro it wouldnt make it down the driveway with out running out of juice. i had the batteries tested and one cell failed horribly. i repplaced that battery and it ran great for a couple weeks. (riding almost 7 miles a day with no charge in between rides) As time went on it slowly deteriorated in performance so i replaced the other two cells as well. So now i am running on batteries that are all less than a month old. I ride this thing to work which is 1.3 miles away. I used to be able to ride there ride back for lunch ride there and ride home all on one charge. Now i can barely make it there. I pulled the rear end off and one of the bearings has gone bad. When i spin it on my finger it doesnt spin very well at all so i think that might be a contributing factor in it but i dont think that is the true cause of my short range. Well now that you have the back story i would really appreciate some input as to what i can do to fix it so i can have something reliable so i dont have to drive my car. I feel like im rather mechanicly inclined seeing as i have rebuilt cars etc and worked with gas and electric rc cars but this thing i cannot figure out to save my soul so any help would be appreciated.
thanks in advanced
David
David,
The bad bearing would cause some extra drag, but it doesn't seem like it could account for the big drop in your range.
I suspect the batteries and/or charger. My first guess is that the three batteries are out of balance and by string charging with the stock 36V charger, you continually made it worse until the entire pack is useless.
Check the voltage of each battery individually and record it. Now charge each 12V battery separately with a 12V charger. Measure the voltage in each battery after charge and compare to before charge and to each other. After all three batteries have been charged separately, take it for a spin and let us know what you got.
When you're replacing the wheel bearing, make sure the pads are not rubbing on the brake disc.
well heres a lil update...i checked each battery and they all seem to be fine...i charged it up and tested each. each gives off 13v and the pack gives off 39v. i got the wheel off the ground and ran it for a while. (yes i sat there and watched it run for like 15 mins) as it was running i applied the rear brakes in small incriments to simulate a load. when the lil meter said it was dead i tested the batteries again and they still read 38.9v. so the batteries still had a really good charge on them. Earlier in the day i rode it down the block and back and let it sit for about five hours turned off and unplugged. I then rode it down the block again and it instantly fell into yellow. so i thought there was a parasitic discharge so i left the meter on the pack for about 3 hours and the charge dropped to 38.8v. another thing i did was meter the plug goin to the motor and when i turned it on it would spike at 36v and then rapidly drop and if i hit the throttle it would spike then drop all the while not getting back up to 36v. does this mean my controller is bad? any imput would be great.
thanks for the help fellas
David
anyone have any input?
David,
I was waiting for someone else to add a new idea.
I don't believe it is your controller since the voltage dropped in 5 hours with the switch off. I still suspect your batteries. Just because they are new, does not mean they have much capacity. They may not ALL be bad, but you need to test each one individually to find out.
Charge each one separately with a 12V charger at no more than 2A and note the resting voltage. Apply a "load" of maybe 25-30 amps or more, and record the voltage after a certain period (say 10 or 20 seconds). Do this with each one and compare the ending voltages. I'm guessing that you will see one or more that drops like a rock.
There are comercial load testers on Amazon or e-bay, or you could hook up anything that will draw at least 1000 watts and have an ammeter so you know exactly what the load is.
How long does it take your 36V charger to recharge the entire pack after it has "gone red" and quit? If the batteries have lost capacity, they will discharge as well as recharge much quicker.
It's never a good idea to leave lead acid batteries in a state of discharge. Recharge after every ride if possible.
Hope this helps. Please let us know what you try and what worked.
Harlow
One more thing you can try is to charge all your batteries individually as suggested (don't let the voltage pass 15 volts per battery) then take a ride until the scooter seems to be running out of juice. Now test the voltage on all 3 batteries individually. You may find that 2 of them are at 13 volts and one is at 9 or 10 volts...that's your bad battery. I have had 2 s-750's and one stealth 1000 and within a very short time (like a month or 2) all three OEM chargers failed. And they all failed the same way. They would charge without ever going to green or float voltage which if I wasn't keeping an eye on things would have fried my batteries. As a result I would recommend that you NEVER trust the OEM charger to work properly without keeping an eye on the voltages. I purchased 2 soneil 36 volt 2 amp chargers I think the model is 3602S from www.electricrider.com about 4 years ago and have never had a problem with them. One other point worth mentioning is that most brand new batteries need to be broken in. They will not act correctly until they are. To see exactly what's going on with my batteries I charged them individually with a digital adjustable dc power supply. It has a display screen that shows amperage and voltage so you can see exactly what's going on with the battery at all times. When a "broken in" battery is discharged and then hooked up to a charger (or dc power supply in this case) the amperage will lock at whatever the charger is rated at...lets say 2 amps and the voltage will begin at whatever the voltage of the discharged battery is (lets say 12 volts). The voltage will slowly creep up to approximately 14.5 volts. Then the voltage will lock at 14.5 and the amperage will start to drop until it reaches a certain point(probably one half amp or so) then the charger will cut the voltage down to about 13.5 volts or so and the amperage will continue to drop until it reaches somewhere around five hundreths of an amp. That is a fully charged battery. With a battery that is not broken in that is discharged (lets say to 12 volts) when you begin charging everything looks the same at first until the voltage begins to reach 13.8 or higher. If the battery is totally not broken in the voltage may never reach 14.5. It may go as high as 14.2 and then stay there a while and then start going backwards...14.1...14.0 etc. If it's somewhat broken in or brand new but not too terribly in need of being broken in, the voltage may reach 14.5 and the amperage may start to come down, but it may not get below 1.0 amps and then stay there a while and then start to go back up again. This will prevent the charger from ever going to float voltage and can fry new batteries if left on overnight. You can imagine what could happen if you have one battery that's broken in, one that's almost broken in and one that's in desparate need of being broken in if you charge the batteries with a string charger. The broke in battery might end up getting 18volts or more before it's all over. If you don't have individual 12 volt chargers and want to break in your pack you can do what I did. I just rode my scooter a couple of miles and then charged it about a half hour, rode it a couple more miles and charged it another half hour until I did that about 10 times. Then I left it on the charger and monitored the voltages of all 3 batteries. If they stayed pretty much together then I left it alone. If they started getting out of synch then I rode it 2 more miles and tried it again. You usually won't notice any big difference in voltages when you first hook up the charger, you will notice the biggest difference if one battery begins to reach 14.5 volts ahead of the others. If the other batteries are around 13.9 and 14.1, the voltage of the 14.5 battery will begin to climb past 15 volts fairly quickly. At that point you should unplug the charger. Those batteries don't like going past 15 volts at all. Assuming the batteries are not defective in some way when they're broken in they will eventually all be within a few tenths of a volt of eachother...sometimes within a few hundreths of eachother. I got 2 years out of one pack after breaking it in that way. And that was riding it probably 30 to 40 miles a week, and recharging after each use (this is a must if you want the pack to last). It's a 5.7 mile ride to work for me one way with 2 small overpass type hills and I retired the pack when it would no longer get me all the way to work anymore. The furthest I ever went on one charge with that pack was 11.2 miles in hot weather with tires at 45 lbs. and wide open throttle most of the time with almost no stopping. Usually I could get 10 miles pretty easly in 80 degree weather but in 50 degree weather a new pack might only get 6 miles. They don't like cold. Good luck! Frank