Mysterious power loss/motor bearing update

Hi

Powering home from work today I suddenly lost power. This is bad as I'm not able to peddle normally. I had previously sent my motor to Earl of the Powerridestore to get a new free-hub and check the motor bearings. He gave me a great deal. It turned out the motor bearings were shot. He said he'd never seen anything like it. So he put in new bearings which stopped the squeaking I had posted about here before. There is still a problem with the free hub though as it does not screw into the motor. It's basically held on by the frame or a lock ring. It's very stiff to peddle and threatens to lock up. I put off calling or working on fixing this problem because I could motor to and from work easily without pedaling.

However that changed today. I should have have plenty of power to get home as I had been charging for 4 and half hours at work. When I lost power I noticed the Xlyte controller was still lit up but dimly. After I walked/coasted home I tried charge the batteries. This is an xlyte 36v sla 2.5amp charger. It just kept blinking green when usu. it stops when I charge it. I took off the battery pack and checked for lose connections. Nothing was very loose. I don't understand why the batteries won't charge or if that's the main or only problem.

There was a thunderstorm today. And it started raining just a little before I got to work. I don't think that affected anything but there's a possibility. also the power cut out when I was at work too. Maybe something happened there. But everything seemed fine and I made it for 4+ miles before anything happened. I also accidentally left the controller on while I was charging it today.

Ideas?

Do you have a voltmeter? First thing I'd do is check the voltage of each battery. A fully charged SLA will be 13-14 volts, depending on how long it's been off the charger. SLAs are almost fully depleted at 12.0 volts.

Thanks Xyster. I've got a bit of a learning curve here. I wondered if I should post in the basics section as this area can seem very high level sometimes.

I was reading the ev business thread where you sound like it's totally simple to build your own battery pack. I can surely figure this out. It sure would be nice thought if I could take that consumerist way and just buy something that's powerful and works for a reasonable price.

OK, so I got a multi meter.(after being distracted by someone bringing me a baby bird to save) I get 12.6v,11.6v,and 12.6v from the batteries. Maybe the middle one is bad. I get 37.5 or so coming out of the pack total. I get a reading of 38-40 on the charger.

I wouldn't think that a battery would fail all of a sudden like that though. I wonder if the charger is working the same even when the green light is blinking. I am carrying my charging back and forth in a backpack wrapped in a towel. I think my last charging stopped working from being banged around in the bag. btw I have two non-working 36v chargers if you or anyone is interested.

I wonder if I should open the controller and look for burnt things.
Earl recommended a shower cap for the controller.

Parker said:

OK, so I got a multi meter.(after being distracted by someone bringing me a baby bird to save) I get 12.6v,11.6v,and 12.6v from the batteries. Maybe the middle one is bad.

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SLA with no-load 11.6V is definitely EMPTY. With the other two 12.6V in series, the overall voltage could drop below 24V if heavily loaded (from 37.5V with no-load).

If the overall voltage is below 29V, the LVC of the controller will cut off the power to the motor.

OK, so I got a multi meter.(after being distracted by someone bringing me a baby bird to save) I get 12.6v,11.6v,and 12.6v from the batteries. Maybe the middle one is bad. I get 37.5 or so coming out of the pack total. I get a reading of 38-40 on the charger.

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That 11.6v battery is either faulty, or was never charged to the point the other two were -- in which case your pack is seriously out-of-balance. I'd try charging just the 11.6v battery with a 12v SLA charger (can be bought new for ~$20). See if it'll hold a charge over 13 volts; and then bring up the other batteries to the same voltage; and then take it out for a ride and check the voltage of each battery afterwards to make sure they're all still within 0.1 volts.

You can replace with alligator clips whatever plug the 12v charger comes with. Then, whether or not you have to replace this battery, use the 12v charger to occasionally rebalance each of your SLAs (just don't do it while simultaneously charging with the 36v charger, and don't hook-up the alligator clips backwards!). A tightly-balanced SLA pack will live a longer, more productive life. The $20 charger will thus pay for itself.

That's what I do with my scooter and Currie ebike SLAs.

Problems Solved

I got some cables and batteries and miscellaneous stuff with my bike and I thought for sure this batteries were dead after I read about how SLAs should be babied to maintain them. And the only reason I got some them was to show an example of them wired in series. But low, two of the 6 bats had 12.9v. I switched out the bad one and the pack charged normally

I also solved the problem with the free hub. There is a nut inside that needs to be unscrewed to the point were it prevents the frame from rubbing on the frame. I just took it out for a test ride and came back with the EV grin.
I'm feeling positively towards Earl at powerride and not so positively towards the folks at my local bike shop who first mounted the motor.

Next up I need to find i better place/way to attach the controller. Right now it's got these bungy like cords with a plastic ball on one end holding it to the battery pack. I can't check the batteries without a hassle that entails a chance of pain to my fingers.

The rack that holds the bats is squeaking where is is attached to the seat post even after tightening. With everything else so nice and quiet it's be nice to stop that.

Oh, I ordered the 12v charger from batteryspace before I figured out I had a good battery. I guess I still can have balanced cells now. And I can use that one when I move to 48v 8)

Glad you got it fixed! And now that you had a good excuse to get that extra 12V charger, you have a good excuse to go to 48V, which will give you a 33% wider EV grin. See how that works?

xyster said:

...use the 12v charger to occasionally rebalance each of your SLAs (just don't do it while simultaneously charging with the 36v charger,

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Ok, time for a scary/stupid question, first preceded by my admission to having done that only once in an "emergency" situation.

I came home from work one day and connected up my chargers to the batteries. Ten hours later I happened to go and look at my bike to perhaps work on my headlight modifications. To my horror, I realized I hadn't turned on the chargers. The batteries take a good seven hours to recharge after my 26 mile commute. I had three and a half to four hours before I had to leave for work. It's confession time now. I have two 24v chargers that I use. I then grabbed two 10a 12v automobile chargers and connected them each to one battery of the pair. So now I have two 12v batteries being charged by one 24v charger and a 12v 10a charger to each one in the pair. I gave it an hour and a half and then switched to the next battery bank. I was able to get the charge into the batteries in time and make my ride to work. That was the only time I'd done that and like I wrote it was an "emergency"

Now for my question. Why not use multiple chargers? Is it an issue with a "ground plain" or something else? If I can tap into one of my batteries of the 48v pack and pull 12v from it while drawing off the main pack for the motor. Why can't I do the reverse and put 12v into one battery while charging the pack?

I wouldn't make a habit of the act but the stern warning gave cause for concern.

Interesting question, Bill.

I diagrammed your situation. Looks to me like if, and only if, the chargers are isolated (not sharing a common ground) then you're OK. And it's that difference that separates this situation from the one where current is being pulled from the same pack at different points into two different loads.

Either the negative or the positive of both chargers connect together at the battery (or batteries) they're both charging. If they aren't isolated, then both terminals of the 24v charger connect to both terminals of the 12v charger. If they are isolated, then only one terminal of the 24v charger connects to one terminal of the 12v charger.

I'm not totally clear on this answer. The situation prima facie "sounded" to me like a short circuit. Hopefully someone else smarter about these things can chime in.

xyster said:

If they are isolated, then only one terminal of the 24v charger connects to one terminal of the 12v charger.

I'm not totally clear on this answer. The situation prima facie "sounded" to me like a short circuit. Hopefully someone else smarter about these things can chime in.

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Well it looks like my were isolated
I'm feeling a bit better now. No 4th of July firework show. But I did cause sparks to fly on another occasion, however I'm trying to forget that light show. Smoke tested some 12g wire real fast