Testament to Ping's Infragility

SamSpeed

SamSpeed

1 W
Joined
Jul 22, 2008
Messages
52
Location
Hillsboro Oregon
Late last night, two blocks from home, WOT in the twenty-somethings there was a sudden shifting of weight, a loss of power, and a sound that was cross between a thud, a splat and a silent scream. Frozen, petrified I hurtled through the darkness listening to the sound that become sort of a dull bounce growing softer, and slower.

16 pounds lighter, I turned around finally to see what I feared most. And there it was. On the ground. My Ping battery not 2 weeks old, alone and abused.

Now don't ask what happened or why, 'cause I really don't want to talk about it. But I'm here to tell you that after I strapped it back on and plugged it back in, it gave off a re-assuring spark. After all that mistreatment, like a happy puppy, that battery pack sat up and said, "Let's Go!" All the corners are bashed and scuffed but all seems well. It still accepts a charge and still delivers. What more can you ask?

Ping must use a really high-quality ducktape!
 
Pictures please! :lol:
 
You should probably open it up and check all those corners and make sure each cell has separation. I damaged the corner of one of my pings and kept using it, since all appeared fine. It was until using it for 2 more days that the short occurred and I lost one of the parallel group of cells and the end that was damaged. I wouldn't charge it in the meantime either. Those cells swell slightly during charging, and that swelling may be enough to create a short either between cells or within a damaged cell. Proceed with caution. BTW, after replacing the cells I killed back in July, my pair of ping 36x15's are working fine.

John
 
Try that with a spot welded round cell pack though! Prismatic rocks. But box em up, its not if, it's when. A bag is just not always enough when the ping hits the road.
 
Followup: not quite so infragile.

Well, things did not turn out so well. My original post was mainly based on baseless optimism. It's true that it worked pretty well for the next few days, but things deteriorated gradually.

I'd been busy with other things, the bike did not get much attention for a month or so. During that time I kept it on the charger and noticed that it would cycle on and off more and more frequently. Finally took out the xacto knive and carefully exposed the top of the cells to check the voltages and check the damage. One corner was badly deformed, and that group of cells was about dead. The opposite corner had less damage but the voltage was only down slightly (it eventually came up and seems to be as strong as the rest).

At full charge, most of the groups were between 3.70v and 3.72. One with damage was about 3v. This is the corner where the positive lead attaches.

After discharging slightly at about 3amps with a resistive load. Most groups were around 3.3 with the bad one down to 2.6v. Then after sitting for a few hours the voltage was below 1! I'm guessing the cells were shorted internally, causing the self-discharge. NFG -- non functional gear in other words.

So I traded a few emails with Ping and he sent me some replacement cells, and I paid him gratefully. It was time consuming, to identify which cells were bad. Soldering was tricky, the tabs are delicate, but with care it can be done. With a fresh coating of ducktape, it's back on the road -- longest ride was 17 miles at wide open throttle and that's close to the theoritical limit. The Aotema draws just under 25 amps at around 23mph.

Learned a couple of lessons. Never skip your pre-flight inspection. Secure your batteries. Also got to learn about the BMS, how it behaves and the importance of balancing the cells. It's one thing to read about it, but another to get your hands dirty. The chain is only as strong as it's weakest link, and these battery packs have many links.
 
Mines in an aluminum box, and the aluminum box is in a steel box, that is bolted to the rack. Box em up.
 
My buddies wife once drove home from the mall, and a little red light on the dashboard came. Looked something like a little red oil can. She thought, "Oh, I guess I need oil." She drove another 20 miles home, then checked the oil. It was a bit low (ya think?). She added a couple quarts of oil herself, without mentioning it to her husband. :shock:

A couple days later.......
 
What could her husband do at that point though? Wouldn't the damage be done already? 20 miles home. Man.

She didn't put the oil in the gas tank did she?
 
Link, told you not to ask. But since you did...

It was careless anxiousness. I had strapped the battery to the rack in a very temporary way with bungee chords. Yeah, I know not the best of ideas, but I wanted to make it go. Weather here was nasty and I made just a few rides. One day it was clear, and I went to the grocery just a few miles away. Well, one of the bungees went around my load in the side basket and when I got home took it off, tossed it aside and headed off smiling to the kitchen. Then days later got to thinking how well the bike was running, how much fun that last ride was, and got that urge to go. I just bundled up, hit the switch and took off. You see, that bungee left behind on the floor was the one securing the battery. Stupid.

Like I said, inadequate pre-flight. Very common finding in NTSB investigations.

Somewhere, in this forum I read about a fellow with a Ping that was damaged in shipping. Wish I could find it again -- the discussion was that some of the cells that were physically deformed also did not work so well electrically. That, if nothing else, is a good reason to not use bungee chords.

Anyway, it's up and running. Not quite as good as new. I expect it to have diminished capacity. But that's ok, it seems to run in the family.
 
Don't use a metal box. Even those could bounce the battery - from inside if not secured tightly.

Instead, use this - http://www.smooth-on.com/Rigid-and-Flexible/c10_1121/index.html?catdepth=1

All you need is about 1 inch clearance on all side and will take the shape of the bag/box. Whats good about this is that its not sticky like stuff you buy at home depot. This was made for creating cushioning material (and masks).
 
leamcorp said:
. . . Whats good about this is that its not sticky like stuff you buy at home depot. . .
Click to expand...

So you're saying this stuff will stick to the battery?
pACE3-1160145dt.jpg


That's a shame. There are a couple of cans at work that are fated for the trash. I wonder if I can overcome the stickiness somehow. The stuff you linked looks great, but at a price.
 
They use that great stuff for packing things all the time. you put the item in the box, then a trash bag, and fill the bag with the foam. It is super sticky, wait till you try to wash it off your hands.

On my rig, I have the aluminum cookie sheet folded into a very tight fitted box around the battery, then inside the steel toolbox, a few chunks of closed cell foam from some anti fatigue mats fills the inch or so of space left between the two metal boxes. It doesn't matter how you do it, just keep the thing from rattling around in there too much somehow. For me most of the year, heat is a big issue, so I needed a way to heat sink the thing, not insulate it.
 
Unfortunately they are sticky when wet (but not when its dry). I did see one that was not sticky - made by another manufacturer at home depot.

The other thing you need to know about Great Stuff is that it becomes rigid when dry. I thinks semi-rigid stuff is better for cushioning material.
 
and great stuff will not "harden" inside a closed trash bag. it needs air to solidify....
 
leamcorp said:
The other thing you need to know about Great Stuff is that it becomes rigid when dry. I thinks semi-rigid stuff is better for cushioning material.
Click to expand...

That's true. Ok, you sound familiar with the Flexfoam-it stuff. It looks like they sell it rated as 3-pound, 5-pound, 10-pound, or 25-pound all at similar trial sized prices of around $25-35. Which do you recommend?
 
hey yeah. no need to trash it. the foam is really useful for alotta stuff.

recycle it by giving away to someone. otherwise it just ends up in a landfill here in eastern oregon.
 
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