Ping 2.0 Reports

[jha07]

Hi jha07,

You are not alone buddy, I am in the same boat with 2 suspect cells. Waiting for replacements from Ping at the moment. All symptoms sound the same, false peak by the weak cells then upto an hour of requent pulsing (on/off) by the charger as the BMS trys to balance the pack. Weak cells then self discharge or drop voltage over time to around 3.4. I am suspect the weak cells cause the BMS LV cut out to trigger well before the remaining cells get close to the low voltage cutout.

Have tried all Pings suggestions, leaving it charging for 24 hours, individual cell charging with my RC charger (3.6 cut out) but it made no difference, on the cycle program with 1A discharge to 2v I only get around 1500 ma.

Pretty frustrating after reading all the good reports from everyone else, even more so considering my cheepo 4 ah lipo rc pack has faithfully churned out 1000 km now withou a glitch and cells have remained within .01 of a volt with out balancing.

My wife commutes with the Ping pack and is busting my nuts to get it sorted, only 600 km on the clock so far (6 amp current limited)

Will let you know when the cells arrive

Cheers
Derek

Well, I guess I feel a bit better that I'm not the only one having problems. My replacement cells arrived a few days ago and I have them replaced now. Of course the new cells are not at the same charge level as the others, so I'm trying to charge the new cells up to the same level now. I will know soon if all is good or not.

It is pretty frustrating having problems with a pack that is so new. I had maybe 15 cycles on mine before I noticed the balance problem. On top of that, my pack didn't even work when I first got it. It was due to another bad cell. So I'm really hoping the rest of these cells don't give me any more problems.

 

[dogman dan]

We are all at the mercy of the factory quality controll. Hopefully china will learn from japan.

 

[mingonn]

Unfortunately it's middle men like Ping who seem to be trying to provide a good product and service that are going to get burnt. I'm sure the guy is running on a shoestring compared to western standards, I doub't he has factored in alot of extra to cover dud cells.

I had to replace two of mine with less than 50 cycles on the pack, it seems to be ok now but I checked cell voltages after cut off and it looks like another might be on the way. 2.78 compared to the rest at 3.1 - 3.2.

I'm sticking with RC lipo in the future, my cheepo ebay pack is showing no signs of slowing or inbalance at 1500km.

Derek

 

[mcstar]

We are all at the mercy of the factory quality controll. Hopefully china will learn from japan

Let's see, Japan has about 1/10th the population of China and it took Japan about 10 years in the American market to start focusing on quality (1980 => toyota : 1990's => Lexus), so it should take China 10years * 10 times the population == 100 years to get them all focused on quality right?
:lol:

 

[jha07]

it seems to be ok now but I checked cell voltages after cut off and it looks like another might be on the way. 2.78 compared to the rest at 3.1 - 3.2.

That sucks. Did you check the voltages right after charging to comfirm all the cells were fully charged?

 

[swbluto]

Well, generally, price is proportional to quality(With more than a handful of exceptions(Such as quality control differences between automated-manufacturing and hand-made goods), but higher quality products are almost always more expensive then the cheapest available.). As long as we insist on the lowest price and the lowest price can be found in the land of cheap labor, China, you know what we can expect.

 

[docnjoj]

My new Ping saved my butt today! I was testing my brushed Crystalyte on my trike while waiting for steel gears for the Bafang and started by drifting down my 1/2 mile 8% hill. As I made my turn at the bottom, my derailleur got eaten, so I had no ability to pedal! I have never gone without pedaling as my trike and I weigh over 300 lbs, but it went back up the hill without missing a beat. The motor was quite warm at the top, but it saved me a half mile push of a heavy trike! Ping is da man! I have never before had the power to ride uphill without pedaling!
otherDoc

 

[mingonn]

jha07,

I have been leaving the charger on over night as ping suggests to allow the cells to balance. Straight off the charger all cells are the same but after an hour that weaker cell shows up as a slightly lower voltage.

With the bms its always the weakest cell that triggers the lvc, I didn't notice that cell previously because of the two that were really stuffed. Not sure if it will be a problem though, range and performance is more than acceptable. So for now I am just keeping an eye on it.

Pack performance is great though, my wife loves her Ping powered ebike. I don't notice any performance drop all the way through. I got 20km out of my little 4ah Ping pack yesterday before it cut out, full throttle and with very little assistance.

By the way, I don't usually get anywhere near lvc, just doing it to cycle in the new cells.

Derek

 

[jha07]

jha07,

I have been leaving the charger on over night as ping suggests to allow the cells to balance. Straight off the charger all cells are the same but after an hour that weaker cell shows up as a slightly lower voltage.

With the bms its always the weakest cell that triggers the lvc, I didn't notice that cell previously because of the two that were really stuffed. Not sure if it will be a problem though, range and performance is more than acceptable. So for now I am just keeping an eye on it.

Pack performance is great though, my wife loves her Ping powered ebike. I don't notice any performance drop all the way through. I got 20km out of my little 4ah Ping pack yesterday before it cut out, full throttle and with very little assistance.

By the way, I don't usually get anywhere near lvc, just doing it to cycle in the new cells.

Derek

That does sound like it could be the next to go. All of my good cells are able to hold their voltage for 24 hours. I'd be interested to know if that cell of yours gets worse.
My daily commute is around 30km, and when my 48V 12Ah pack was brand new, I got around 40km. My balance problem slowly decrease my range down to about 28km, leaving me to pedal the last few k's. I'm sure it would continue to get worse if I kept using it. I guess I wouldn't have known there was a problem if my pack was 20Ah and I didn't come close to using the full pack capacity.

 

[mingonn]

My pack is made up of single cells in series, yours will have groups of 3 cells in parallel which are then wired in series. The bms manages each group as a single cell I think. I suspect that is why mine showed up so quickly, any weak cells have no where to hide.

Hope Ping starts selling single cells soon for when my warranty runs out.

Derek

 

[swbluto]

Hope Ping starts selling single cells soon for when my warranty runs out.

He already does and he purposely keeps some back-stock on hand for warranty services and related problems. That's kind of how I was able to get the Ping 1.0 cells recently which he had run out for sale over a month ago.

 

[jha07]

I was finally able to test my pack after I had replaced the bad cell. I didn't completely drain it, but I did go 33km and when I checked the voltages afterwards, there was only a 0.02v difference between all the cells. Also, the new cell has been able to hold voltage after being charged. I still want to test the pack's full range, but I'm pretty confident that it's back to normal.

I also tested the group of 3 cells that I removed. As I suspected, only one of the 3 cells are bad. So if my pack does go unbalanced again, and I really hope it didn't, I do have 2 extra cells to fix it.

 

[dogman dan]

Yay! Now that you know how, you could offer pack fixing service and keep even more good cells as part of the fee.

 

[swbluto]

I also tested the group of 3 cells that I removed. As I suspected, only one of the 3 cells are bad. So if my pack does go unbalanced again, and I really hope it didn't, I do have 2 extra cells to fix it.

That was my suspicion as well. However, since the 2 other cells supplied an unusually higher current to the weaker cell due to the lower voltage of the weak cell and the low resistance between the cells in the parallel group, they've been "used more roughly" than the other cells in the pack so they'll be shorter-lived, on average, than the pack's other cells, on average.

 

[jha07]

I also tested the group of 3 cells that I removed. As I suspected, only one of the 3 cells are bad. So if my pack does go unbalanced again, and I really hope it didn't, I do have 2 extra cells to fix it.

That was my suspicion as well. However, since the 2 other cells supplied an unusually higher current to the weaker cell due to the lower voltage of the weak cell and the low resistance between the cells in the parallel group, they've been "used more roughly" than the other cells in the pack so they'll be shorter-lived, on average, than the pack's other cells, on average.

That is a possiblity. But seeing as I only put a total of 15 cycles on this pack, and I'm assuming the pack only starting going out of balance 5ish cycles ago, I don't think that's enough to make too much difference. Also, my motor draws an average of 8A, so even if all the work was done by 2/3 cells, that's still just 1C.

 

[jha07]

Yay! Now that you know how, you could offer pack fixing service and keep even more good cells as part of the fee.

It would be nice to have extra cells, but I don't think if I'd want to offer a pack repairing service. Not that it's extremely difficult to replace a cell, but it can be time consuming. I spent over 2 hours on it. The balancing takes a lot of time as well. Besides, I think most people that have had soldering experience before would be able to do it.

 

[swbluto]

I also tested the group of 3 cells that I removed. As I suspected, only one of the 3 cells are bad. So if my pack does go unbalanced again, and I really hope it didn't, I do have 2 extra cells to fix it.

That was my suspicion as well. However, since the 2 other cells supplied an unusually higher current to the weaker cell due to the lower voltage of the weak cell and the low resistance between the cells in the parallel group, they've been "used more roughly" than the other cells in the pack so they'll be shorter-lived, on average, than the pack's other cells, on average.

That is a possiblity. But seeing as I only put a total of 15 cycles on this pack, and I'm assuming the pack only starting going out of balance 5ish cycles ago, I don't think that's enough to make too much difference. Also, my motor draws an average of 8A, so even if all the work was done by 2/3 cells, that's still just 1C.

Well, the damage is probably more substantially limited in your case! I only noticed mine after the 12th cycle, but since it had a previous owner who put 50-60 cycles on it, it could've been about 50-60 cycles later after the problem more fully developed.

Do you think ping does any QC testing on the individual cells or do you think he more largely assumes they're good and tests only the barest of basics(such as it's not dead; it actually charged to 3.3v or higher) and then does something like a one-time pack testing?

 

[jha07]

Do you think ping does any QC testing on the individual cells or do you think he more largely assumes they're good and tests only the barest of basics(such as it's not dead; it actually charged to 3.3v or higher) and then does something like a one-time pack testing?

If I had to guess, I would think he doesn't test every cell. Only because it would be very time consuming to do so.
Also, my pack didn't have this balance problem at first. If it did develope after 10 cycles, you would need to cycle each cell >10 cycles to weed out this problem.

 

[fifthmass]

I have a testimonial about the new Ping pack. I have the 48v 20ah version and just put it through a full and unintentional deep discharge and was astounded at the mileage I got.

I live in Everett, MA (just north of Boston) and took a Sunday ride up to Westford, MA (30 miles) to meet someone at my sportsman's club. My intention was to get up there fast, put my bike on charge in the clubhouse and go down to the rifle range with my friends for a couple hours. Two hours of charge would give me enough juice for a fast ride home by dark.

Only problem was that half the town had no power because of an ice storm we had here last week. That half of Westford included the sportsman's club. I thought I was screwed since I figured I had used over half the pack's capacity on the ride up. Rather than beg a ride home I figured this would be the ideal test for its extreme range so I decided to bike home and see what happened. Bear in mind the pack was in 32 degree conditions for 5 hours total so the thermal derate had me worried a bit too.

Going home I limited my speed to 15 mph, constant pedalling, and 10 mph on hills with stronger pedaling.

The damn thing got me home with just the first flickering of the LVC warning light at 60 miles total with 800-900 feet total elevation gain round trip. Overall 17 wh/mile.

I'm very impressed with Ping's products and plan on getting a 12 ah supplemental pack to get me up to Lake Winnepesaukee next summer.

Regards, Bill

 

[monster]

so is it easy to repair a ping pack?

with my old Nimh packs i could just remove bad cells. could you do this with a ping pack to prevent the early low voltage cut-off or would this cause BMS problems? do we have any test data yet on the surviving cells in a 3 paralleled group?

 

[jha07]

so is it easy to repair a ping pack?

with my old Nimh packs i could just remove bad cells. could you do this with a ping pack to prevent the early low voltage cut-off or would this cause BMS problems? do we have any test data yet on the surviving cells in a 3 paralleled group?

It's not terribly hard to replace a cell on a ping pack. The tricky part is unsoldering the cell tabs from the board it's soldered on. The tabs are fed through a slot in the board, and it can be tricky to remove it.
I don't believe you can just remove a bad cell since the bms is looking for voltage from every cell. But maybe someone knows a way to bypass this.

 

[dogman dan]

Not bad at all fithmass Lets see somebody do 60 miles with a round cell bargain pack.

 

[ZapPat]

Someone posted a pretty good duct tape battery repair guide here on ES somewhere... use the search to find it (and maybe put a new link to it here if you find it!). I might have a copy on my hard drive...

 

[monster]

how complicated is the BMS? can you add more cells in parallel to cell groups? to make a 25ah battery from another donor battery.

or does the BMS monitor individual cells?

 

[jha07]

how complicated is the BMS? can you add more cells in parallel to cell groups? to make a 25ah battery from another donor battery.

or does the BMS monitor individual cells?

The bms monitors each cell group, not each cell. So you could add more cells in parallel to a cell group. But you'd have to do this to every cell group for it to be useful.