I see that Ping started selling his batteries early this year and I was wondering how they were holding up over time. Specifically, has anyone measured the decrease in battery capacity over the battery's lifespan and number of charge cycles and usual depth of discharge?
How are the Ping packs holding?
- Thread starter swbluto
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needWheels
1 kW
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- May 27, 2008
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- 481
Ping can't sell any more batteries until after the Olympics are over (24th August).
From everything I have read, Ping's packs only shortcoming is the low C ability, meaning if you have hills to deal with you want a 15ah or 20ah pack since you can't draw more than 2C or so?
Apparently not all LiFePo4 are like that, I think I read LifeBatts can do 5C or 10C ?
But they are typically much more expensive.
I guess LiFePo4 is like NiMh in that regard - many cells (ie. D) can only do 1C but if you switch to sub-C you can get 10C (or more) from some brands/models.
All I know for a fact is I've had SLA for 2 weeks now and I am already sick of it's "quirks".
From everything I have read, Ping's packs only shortcoming is the low C ability, meaning if you have hills to deal with you want a 15ah or 20ah pack since you can't draw more than 2C or so?
Apparently not all LiFePo4 are like that, I think I read LifeBatts can do 5C or 10C ?
But they are typically much more expensive.
I guess LiFePo4 is like NiMh in that regard - many cells (ie. D) can only do 1C but if you switch to sub-C you can get 10C (or more) from some brands/models.
All I know for a fact is I've had SLA for 2 weeks now and I am already sick of it's "quirks".
dogman dan
1 PW
At least one ping pack has 1000 miles or more on it. Mine is only at about 375 due to a month of waiting for bones to heal. If I get 15000 in five years I'll be real happy. I ride 15 miles per cycle, so 1000 cycles. That would equal 500 gallons of gas in my car. If you project what gas will cost in 4 years, now lithium starts to look dirt cheap. having an ebike that can go 20 miles on a charge is cheap compared to using the car.
dirtdad
1 kW
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- Mar 2, 2008
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- 309
I cannot speak to Ping, I ended up with packs from two competing and now non existent competitors, anna and new.journey. Electrically and short term the packs were great. But the individual cells these are made of are pretty flimsy, mine both fell apart and I sold them to others here to rebuild as projects, you can find the threads on these forums.
Ping uses the same cells, but I understand that Ping builds his backs better structurally. Still, they are duct tape construction, and I am interested in the durability of these packs. Not electrically, but structurally. Can they hold up to the bouncing around long term abuse they get on an eBike? Even if they tend to fall apart after a few years, at Ping prices, they will still be a pretty good deal.
Ping uses the same cells, but I understand that Ping builds his backs better structurally. Still, they are duct tape construction, and I am interested in the durability of these packs. Not electrically, but structurally. Can they hold up to the bouncing around long term abuse they get on an eBike? Even if they tend to fall apart after a few years, at Ping prices, they will still be a pretty good deal.
docnjoj
1 GW
My wife's 36 volt 10ah pack just keeps going! 2 months and maybe 25-30 cycles! She is a perfect rider for this type of battery, as she only uses2-3 amps in 10 miles! I tried it on my trike/MY1018 motor test, and was extremely impressed withthe power! No cutouts and no heat problems! 5X up and down 1/2 mi 8% grade with 300+ lbs of trike and human in 90 degree direct sun! Crazy, but it worked!
otherDoc
otherDoc
docnjoj
1 GW
Oh yeah! The ping has much more power than my well used 42volt NiMh pack!
otherDoc
otherDoc
dogman dan
1 PW
The foil pouches in my ping is one of the reasons for my choice of full suspension bike. And my bad back.
andys
100 W
- Joined
- May 29, 2008
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- 140
I got two of his packs now, and I was one of the first people to try them out when he first started selling them. No problems with either pack, they are compact, have good BMS and chargers, and work perfect for uses where 2C is good enough, like my 900 watt scooter and BMC hub motor e-bike. They don't get hot or make any funny smells. They hold their voltage for a long time on a charge. They will only cut out on you if you try to run them at more amps than they are designed to go. I wish I would have grabbed an extra pack when they were cheap and available.
The high output LiFEpo4 batteries are still very expensive, and they are overkill for small EV's in my opinion. Even a basic 36 volt 10AH high output pack is bulky and weighs twice what Pings pack do. Even if they can do 8c, they are going to only run for 10 minutes if you actually draw that kind of current out of them! Want a 48V 20AH Lifebat to have a good range at a high c rating? Cost way over $2000
The high output LiFEpo4 batteries are still very expensive, and they are overkill for small EV's in my opinion. Even a basic 36 volt 10AH high output pack is bulky and weighs twice what Pings pack do. Even if they can do 8c, they are going to only run for 10 minutes if you actually draw that kind of current out of them! Want a 48V 20AH Lifebat to have a good range at a high c rating? Cost way over $2000
I've got a 20ah 48v pack which was working excellently for a few months until recently. Now my pack cuts off after what I guess is about half discharge. I'm running it with a phoenix cruiser hub, 48v 40a controller. Ping suggested a 48h charge and that didn't work, though the BMS remained warm the whole time.
I took apart the pack and I don't see any obvious loose connections but under the small circuit boards that ping uses it's hard to see if anything got disconnected. I measured the voltages of the 5 cell units and they are all pretty close:
3.44
3.43
3.46
3.46
3.47
3.45
3.47
3.45
3.41
3.46
3.47
3.45
3.46
3.44
3.44
3.43
My current idea is to partially reassemble the pack and do a trial run, then remeasure the voltages to isolate where the problem might lie. Even after that I'm not sure what the next step would be. Perhaps unsoldering the cells? Is it possible that it's really a BMS issue? Anyone have any experience in this area?
Thanks,
Evan
I took apart the pack and I don't see any obvious loose connections but under the small circuit boards that ping uses it's hard to see if anything got disconnected. I measured the voltages of the 5 cell units and they are all pretty close:
3.44
3.43
3.46
3.46
3.47
3.45
3.47
3.45
3.41
3.46
3.47
3.45
3.46
3.44
3.44
3.43
My current idea is to partially reassemble the pack and do a trial run, then remeasure the voltages to isolate where the problem might lie. Even after that I'm not sure what the next step would be. Perhaps unsoldering the cells? Is it possible that it's really a BMS issue? Anyone have any experience in this area?
Thanks,
Evan
powermed
10 W
- Joined
- Jun 22, 2008
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- 80
Seeing as the power of the pack seems normal at first and just seems shortlived, my concern would not be the BMS, but that there's a bad cell somewhere.
Besides each of the 5 subpacks, are there any leads you can tap on smaller groups of cells or best of all, individual cells? If not (I'm guessing it's not) it might help to compare voltages charged against voltages when discharged. Some bad cells might get close to normal when charging, but then fall pretty far under load, or have a diminished capacity.
The problem is with looking at charged packs, is that unless each cell is handled by a BMS, it might miss a bad cell while another cell becomes overcharged in compensation (hence voltage of a pack might not seem that bad in the charged state), and becomes damaged. Longer term the problem then cascades and more and more batteries succumb.
In particular I'd be focused (at first) on the lead cell in each subpack.
As background I noted the Dewalt packs are monitored in groups of 2. I'm guessing Ping is managing each subpack as a unit - that would miss out on a lot of cell information. When I run them I've tapped each battery so I can monitor individual cell volts (and charge individual cells) if need be.
Besides each of the 5 subpacks, are there any leads you can tap on smaller groups of cells or best of all, individual cells? If not (I'm guessing it's not) it might help to compare voltages charged against voltages when discharged. Some bad cells might get close to normal when charging, but then fall pretty far under load, or have a diminished capacity.
The problem is with looking at charged packs, is that unless each cell is handled by a BMS, it might miss a bad cell while another cell becomes overcharged in compensation (hence voltage of a pack might not seem that bad in the charged state), and becomes damaged. Longer term the problem then cascades and more and more batteries succumb.
In particular I'd be focused (at first) on the lead cell in each subpack.
As background I noted the Dewalt packs are monitored in groups of 2. I'm guessing Ping is managing each subpack as a unit - that would miss out on a lot of cell information. When I run them I've tapped each battery so I can monitor individual cell volts (and charge individual cells) if need be.
Rassy
1 MW
Bug500 wrote:
I think the problem is probably your BMS.
I have 48V 20AH packs from anna, but the packs and BMS appear to be identical to Ping's My controller is a WE BD36 with 35 amp limit, but the battery kept cutting out. After getting a Watts Up and wiring it ahead of the BMS, I found the BMS was cutting out at about 30 amps. I first restricted my throttle to about a 25 amp setting, but I missed those other 10 amps on hills. Now I am discharging while bypassing the BMS, but plan to beef up the BMS cutoff so that I can retain the low voltage protection the BMS provides.
I think the problem is probably your BMS.
I have 48V 20AH packs from anna, but the packs and BMS appear to be identical to Ping's My controller is a WE BD36 with 35 amp limit, but the battery kept cutting out. After getting a Watts Up and wiring it ahead of the BMS, I found the BMS was cutting out at about 30 amps. I first restricted my throttle to about a 25 amp setting, but I missed those other 10 amps on hills. Now I am discharging while bypassing the BMS, but plan to beef up the BMS cutoff so that I can retain the low voltage protection the BMS provides.
Rassy
1 MW
As Bill said, it may not be the BMS. When you check the subpack voltages after (partial?) discharge you should be able to confirm this. Just a thought, since you are so close to the 2C limit, does the motor want more amperage for the same amount of power as the voltage of the battery starts to sag? i.e., you may just be tripping the High Amps cutoff of the BMS. If that is the case, you can reset the BMS by cutting off all power (Unplug the controller?). Then when you hook up or turn on everything you will be good to go again.
Just a note, aren't the subpacks of the Ping batteries made up of 4 cells in the 20AH version?
Just a note, aren't the subpacks of the Ping batteries made up of 4 cells in the 20AH version?
Thanks for all the input. I guess the first test I'll run is to discharge the batt and then check voltages. I was planning on doing this today but thunderstorms and electric bikes just don't seem like a great combo. If the voltages on the subpacks are still pretty close perhaps bms modification or bypass will be an option.
