Intermittent acceleration help needed (SOLVED)

When I pull the throttle, the scooter doesn't seem to accelerate smoothly. Feels like a bad driver pumping the gas pedal. Perhaps a lose connection? There are so many wires. Any idea which it could be? I did notice that the battery appeared completely dead for a moment and then kicked in. So perhaps the battery wire? I hardwired it (maybe a poor job of it) so trying not to redo it if it could be something else. Thoughts? Has this happened to anyone else before?

Battery was not empty. Probably 2/3 battery left. This is the ride I'm having trouble with: http://www.endless-sphere.com/forums/viewtopic.php?f=12&t=70650

UPDATE: (if you want to skip the rest of the thread)
The wires between the batteries came loose.

kmxtornado said:

When I pull the throttle, the scooter doesn't seem to accelerate smoothly. Feels like a bad driver pumping the gas pedal. Perhaps a lose connection? There are so many wires. Any idea which it could be? I did notice that the battery appeared completely dead for a moment and then kicked in. So perhaps the battery wire? I hardwired it (maybe a poor job of it) so trying not to redo it if it could be something else. Thoughts? Has this happened to anyone else before?

Click to expand...

If you aren't going to check the wires, who will? Grab your multimeter and do a continuity test, I am granting you permission to troubleshoot all of the connections on your e-bike. If you don't do it, I am tossing your bike into the lake.

http://www.ebikes.ca/learn/troubleshooting.html Bookmark this page.

In the upper right corner there is a search box, be sure to use it in both 'using google search' mode and just forum search mode, they will yield very different results.

kmxtornado said:

Has this happened to anyone else before?

Click to expand...

No way, your totally the first. (sarcasm)

Looks to be that the throttle troubleshooting document is what would be helpful. I read through that and will be doing the test with the multimeter.

I don't know if the batteries may be the culprit. Brand new though. Charged for the first time. For some reason, I'm hearing a bubbling sound coming from the batteries while it's being charged. I only noticed it after about 6 hours of charging. I had charged it in the garage, then had come down 6 hours later to check on it thinking it would be done by then and that's when I noticed the sound. I unplugged it immediately out of concern.

I did some research regarding this but found a lot of conflicting info. Curious what others thought on this forum. I read it's hydrogen that's being released and this happens when the batteries are being charged at too high of a voltage or amperage. No clue on the truth to any of this as I'm a newb when it comes to the technical aspects of all this.

BATTERY SPECS:
Universal Battery brand
Model: UB12150
3 12v 15ah
Standby Use:
13.6-13.8v voltage regulation
2.25A initial current

Cycle Use:
14.5-14.9v voltage regulation
4.5A initial current


Side question: I know I should charge SLA's immediately after use, but shouldn't I at least let them cool down first?

Are you charging your batteries one at a time or connected in series or parallel? What charger are you using and how many volts does it output? You haven't described your charger before. Your cooler originally ran on 2 batteries, right?

Charging in series. Yes, it originally ran on two 12v 18ah batteries. Now three 12v 15ah batteries. Amp hour was reduced to get down to a physical size in order to fit in the battery box that houses the 3 SLA batteries. New controller and new charger:

Charger is a 36v 1.6a
3-port inline plug (although only 2 ports are actually hooked up).

What was the voltage of the batteries after unplugging the charger on the bubbling sound? Or what is it now if you didn't measure it then?

I took it for a short 3 minute spin, but at full throttle to do some testing (cooler isn't reaching the full 20-23mph rating and is currently capped at 13mph and I wanted to try it out again to see if it could reach higher speeds).

Totally almost blew off my finger! Ouch.



Instead of touching the multi-meter leads to the battery itself, I touched it to the charge port figuring it was the same thing. Since I wired it up, I know that one side of the battery leads to one of the 2-pins and the other leads to the other. Shows what I know about the system. Man, that was scary. Big spark, loud pop, and the next thing I know it, I'm screaming and my hand is black. The photo above is AFTER I had already run to the sink to wash it off and cool it down. Finger still throbbing.

Looks like I need 3 new batteries? and from the looks of it, I need a new inline 2-pin charge port. Might have to buy a whole new battery case to get all the wiring unless it's something I can do myself. I bit freaked out to open the battery case though and still worried that something bad inside is happening and I need to dispose of this ASAP.

I got off my butt and unscrewed the top off the battery to discover that I was wrong about the 2-pin connector leading to positive and negative poles of the batteries. So I did screw up, but good news is:

1. I'm alive.
2. Volt meter is okay.
3. Batteries appear to be okay. If one is reading at 12.7v and the other two at 13.0v, everything's good right? If i shorted the battery or the battery died somehow from my fiasco, it wouldn't read the full voltage, right?
4. It seems like it's just the inline 2-pin charge port I need to replace. I have a spare from my other project that I can use. In the meantime, I can always charge the battery through the cooler which has a charge port built into it.
5. No downtime for this weekend's events with the cooler.

All comments, responses welcomed.....yes, even ones that say I'm an idiot for testing the battery using the charge port and should never go the lazy round when dealing with batteries. If there was an emoticon for me to get smacked in the head, I'd use it.

If the batteries read different voltages, they're at different charge levels (SoC). You'll want to individually charge them with a 12V SLA charger to try to fix that. When they are close in voltage then you can parallel them all and put them on that charger for the rest of the charge.


Bubbling probably means the charge rate is probably too high and they are outgassing, which means for SLA that they may be being damaged (hydrogen is forming as water dissociates from the current...which means that water is no longer avialable as electrolyte).

But if the charger really is only 1.6A, that shouldn't be too high at all.

Also, it should not be bubbling at only 13V or less...when I used to use SLA I would only hear that at 14-15V (full charge or past), at currents higher than recommended on the side of the battery.

90% sure the intermittent acceleration is caused by a wiring issue. could be throttle, but more likely a bad contact on one of the wires to the motor.

Thanks amberwolf and dogman. Prior to reading your post, I had considered redoing the connections between the batteries. It was tough to find 7.75mm insulated connectors. All the ones I've come across are yellow for 10-12gauge wire and max out at 6.3mm. On the initial installation, I had just pried the 6.3mm ones wider to fit and figured that would work okay. If anyone knows of any place I can source 7.75mm connectors, that's be awesome.

In the meantime though, I'll try the wiring to the motor first to see if that fixes the problem.

Still at work. Haven't gone home yet. If the connection is found to be bad, I'm thinking of replacing the heat shrink butt connectors with Anderson Power Poles that everyone is raving about. I've got a few extra from my mini scooter project that I can scrape up and reuse here. Might do that anyway since the butt connectors are one time use and I'd have to remove them and reconnect anyway.

The battery box in the cooler is quite a tight fit and it seemed that the speed controller wire was being crimped in between the inside of the cooler and outside of the battery case. Cleaned it up a bit and top speed now is 18mph instead of 13mph and the throttle cuts out less, but still cuts out nonetheless. Turns out I don't have the female side of the Anderson Powerpoles, so I'll need to order some.

Did a voltage test of the battery connection to the controller and got a reading of 38.7v. So we're in good shape as far as the battery is concerned.

kmxtornado said:

... Turns out I don't have the female side of the Anderson Powerpoles, so I'll need to order some.

Click to expand...

Female side? They're all the same.



Powerpole General Assembly Instructions: http://www.powerwerx.com/assembly.asp

Anderson PP tips without the fancy crimp tool.. by Ypedal
http://endless-sphere.com/forums/viewtopic.php?f=14&t=2742

45A Anderson contacts without TRICrimp (just using plain pliers instead) by El_Steak
http://endless-sphere.com/forums/viewtopic.php?f=2&t=18238

Oh! Thanks! I can do it then! Awesome. I'll probably buy more so I can hook up the motor the same way.

The mistake I made was that I touched the voltmeter probes to the charge port which I learned the hard way is an absolute no-no. What I should have done was not be too lazy to take off the lid of my battery case and touched the black and red probes to the appropriate poles on the batteries themselves. It's okay to touch the voltmeter to the connectors too, but never the charge port.

Hopefully but publishing this, it'll help someone from blowing off their finger or in my case, getting a blister (which is healing quite nicely and should be gone in a couple days).

It looks like when measuring battery voltage at the battery charger port he accidentally bridged the meter's probe between the charger port's outside shell and its' + terminal. And that the charger port's shell actually does conduct to battery -.

For myself I'd rather have measured at the battery terminals. The charger port connects to the controller before the battery. Or he could've put some tape around the meter probe first so just the tip was exposed.

kmxtornado said:

The mistake I made was that I touched the voltmeter probes to the charge port which I learned the hard way is an absolute no-no.

Click to expand...

Touching to the charge port is exactly the same as touching to the battery.

The only thing that would cause what you had happen is if you short something together--either the probes to each other, or one probe across both connections, or leaning the probes on the metal edge of the connector and also touching the pins at the same time.

There is nothing to cause a short simply by checking voltage at the charge port.





(and unfortunately it doesnt' matter what anyone posts about mistakes they make and the results, cuz almost all of the mistakes people make are made *before* they ever bother to read anything about what they want to do ).

Oh really? So it must've been that I touched the threaded part of the charge port that's metal. Carelessness on my part. I didn't even think of it when I touched the probes. Makes sense because if you look at the charge port, you'll notice it totally burnt the threads. Oops.

PROBLEM SOLVED:
Short answer is it was the connection BETWEEN the batteries that was the culprit. Tightened those up and viola, it worked! Top speed now is 22mph! Loving it.

THE STORY:
Last night on my test run, I hit 17mph. It still kept losing full acceleration every few seconds. Finally, the whole thing just stopped moving. I had still thought it was a bad connection from the battery cable to the controller, so I replaced that this evening after work. I even stopped by Harbor Freight Tools to pick up a proper crimping tool. When everything looked pretty, I turned it on and nothing.

"Ugh," I thought.

I took the volt meter to the wires connecting to the controller and this time it was way under. Instead of 37v, it as reading 6.8v and wasn't even consistent. Numbers kept jumping around. I tried charging the battery itself thinking maybe I messed up the battery by going full throttle for two long the night before. The charger light wouldn't even turn on solid. It kept blinking red/green irregularly. Since the throttle light wouldn't even turn on, I knew it had something to do with the battery.

Opened up the case, and got 0.6v. That's a bit odd for a 36v battery pack. While I had the battery case open, I replaced the charge port that I burnt the other day. Looked over and saw that one of the connections between the batteries was loose. When trying to fix that, I noticed another connection had completely come off! Ooops. The whole time it was a bad connection between batteries and not the connection between the battery to the controller! Haha. It was that simple!

Before putting battery case lid back on, I turned on the cooler and voila! The lights came on! Put everything back together. Turned it on one more time and still saw lights. Took a test run down the block and hit 20mph! I was trying to get catch a screenshot of it. Bit of a challenge being that I was trying to hold my phone while steering. Not a good idea by the way. I did manage to get a screen shot of my Speed View app at 22mph!



From there, I was smiles cheek to cheek and waved at all the neighbors staring at me as I rode along. Fun times.