Ping 2.0 Reports

[dogman dan]

Well, EVERYBODY else says lifepo4 dies if fully discharged. I rather doubt that the prismatic economy cells can take it. I sure won't try it at home with a good battery.

Some folks with the equipment to do it have reported pretty close to the full amp hours being delivered by new lifepo4 batteries. Bear in mind, it's a specification, not a verified test of capacity for the particular cells in your particular battery. Any ammount of imbalance or undercharging is going to lessen that starting number as will also any manufacturing variations. I would be tickled pink if my battery was to test out for 18 , my bike, usable amp hours from my 20 ah Ping 1.0. I bought the biggest size so I wouldn't need to sweat it, and have a pretty usable battery when it drops to 70% or 14 usable ah.

 

[jha07]

I got the replacement cells from Ping yesterday and soldered them in place. I also noticed that one cell, the one next to the bank of cells that died looked inflated. It was filled with some kind of gas and because of this, it took up more space than the other cells. I didn't notice this before. It may have happened during the week I was waiting for my new cells. I asked Ping about this and he said that cell is definitely bad. It still reads 3.3v but I changed it out anyways. I was lucky that Ping sent me an extra cell
After everything was reassembled, I hooked up the charger and the pack started to charge. It only charge for a few mins before switching off, and then started to cycle on and off. I left it to balance over night, but when I measured the voltages in the morning, 3 groups of cells were still reading 3.3v while the rest were at 3.8v. Since I just replaced one group of cells, I would expect them to be very unbalanced. Ping saids I should let it charge for 24 hours. But I'm thinking it may take a lot longer than that, since not much charge goes into the cell while in balance mode and I suspect the new cells are in a very low state of charge. I guess only time will tell. I don't want to seal up the pack until all the cells are balanced, so I guess I'll have to be patient.
He also sent me a new 5A charger. This charger is the same size as the 2A charger, but probably weighs 3 times more. There must be some heavy duty electronics in there. I gave the new charger a quick test and found it to be much quieter. The fan on my 2A charger is loud and the charge makes a high pitch noise. The 5A charge doesn't make the high pitch noise, and the fan is quieter. Seems like the 5A charge is a high quality charger.

 

[miro13car]

Hi Greag
I bought LifeBatt HPS3610 battery and 8A charger.
Charger was $175
You can see on LifeBatt web site pack but no charger.
Was shipped from Taipei, Taiwan to Calgary.
MC

 

[aaannndddyyy]

I received my Ping lifepo4 V2 battery today it a 48v 12ah pack here are a few pictures,
It got held up a few days in custumes at Stansted Airport London.





I have all the wire and plugs to make the necessary connections just need to fine a hard case to fit it in.

 

[jha07]

I have all the wire and plugs to make the necessary connections just need to fine a hard case to fit it in.

I'm planning to make a case for mine out of some plywood. The two ends will have thicker pieces so that I can screw 4 thinner pieces to it to complete the box. I will also wrap the pack in a few layers of foam before enclosing it to help absorb some shock.
What have other people done to protect their packs?

 

[ZapPat]

From andy's photo above it looks like I could seperate the battery into two thin modules, as long as I extend the BMS wires a bit. Has anyone done this with Pings's batteries yet?

 

[aaannndddyyy]

From andy's photo above it looks like I could seperate the battery into two thin modules, as long as I extend the BMS wires a bit. Has anyone done this with Pings's batteries yet?

Yes that can be done, just the one white wire would need unsoldering then reattached.

 

[geoff57]

has anyone confirmed if you can series the packs, i sent an email and he said these aren't the new generation yet?

Hi Qwerty,

These new packs are not with new generation BMS that support connection in series. But the new generation BMS will be available soon.

Best regards,

Ping

From: Qwerty Access [mailto:qwertya@gmail.com]
Sent: Thursday, July 17, 2008 4:20 AM
To: pingping227@hotmail.com
Subject: The Brand New 24V 20AH

Can these new generation batteries be put in a series? 24V 20AH + 24 20AH to become 48V 20AH?

hi all
just found this thread wondering what ping had been up to.
anyway I have 2 batteries of his a 48v 20ah and a 24v 20ah I had the 48v on my previous bike but desided to go to 72v total so took a leaf out of the first duct tape thread and put in diodes have a look at the posting it might help http://endless-sphere.com/forums/vi...=t&sd=a&hilit=duct+tape+life&start=945#p60793

 

[jha07]

My first ride with my Ping pack didn't go too well. I was a bit concerned that the battery voltage might be higher than what my controller could handle. I had been using a 48V NiMh pack for months, but that pack never got over 60V when fully charged. I remember being told my controller (crystalyte 20A) could handle up to 60V, but since the new pack was over that, I was a bit concerned. I emailed ebikes about my concerned and was tolded the mosfet are good up to 55V. Over 60 would be pushing the limits of it. So for my first ride, I let the battery sit for awhile so the voltage would drop. It was around 59V when I plugged in it to the controller. It seemed fine when I turned it on. Gave it full throttle and had really good acceleration for a few seconds, then my 20A fuse blew. So I replaced it with a 25A fuse, but of course I forgot to turn off the controller first. So when I put the new fuse in, there was a big flash and the new fuse burned out instantly. So I tried another fuse, this time I turned the controller off. When I turned the controller back on, it didn't work. The motor now has extremely high resistance when I tried to pedal. If I unplug the motor, it frees up like normal. It seems that the controller now blows fuses even if it's turned off. I'm assuming my controller is toast. Does anyone have any experience like this? I wonder if the controller can be fix. Maybe new mosfets?

 

[Anonymous]

.

 

[dogman dan]

Your symptoms are very similar to mine when I blew a controller. Bummer. All that waiting for Lifepo4 and now waiting for a controller.

 

[swbluto]

All that waiting for Lifepo4 and now waiting for a controller.

Waiting seems to be the name of the early-adopter game.

 

[dogman dan]

That was why I rushed to buy another complete kit, in early summer. When I cooked a motor I was sure handy to have another. I noticed all the smartest posters had several bikes.

 

[swbluto]

That was why I rushed to buy another complete kit, in early summer. When I cooked a motor I was sure handy to have another. I noticed all the smartest posters had several bikes.

Which of course couldn't be linked to all the smarter members having more money to spend on e-Bikes, could it?

It makes sense the "smarter members" would be naturally more experienced with eBikes(Experience = smarts in a hobby, right?) and more time in a hobby tends to result in more time to acquire goods and, thus, more goods like eBikes. Learning the lesson of "having back-ups" might also have something to do with that.

 

[dogman dan]

Maybe I should have just said, more experienced members. Some of the smarter ones had two or three so they can ride one while rebuilding controllers on the others. For sure time does accumulate more toys.

 

[Fire Mountain]

Hi all,
I've been following the talk on LiFePO4 batteries and finally broke down and ordered a 48V 20Ah from Ping to upgrade from my 36V 12Ah NiMH from Ebikes.ca. It just arrived, I wired it up, charged it up and took it for a test run: OMG!! I'm so impressed with his service and the quality so far seems excellent. By contrast I bought a LiPo from Brian Howell at Electro ride last year (thinking going more local would be better) and was completely disappointed by broken promises, delay after delay for months and finally a refusal to honor his warranty when it melted down.

To reiterate what many of you have already been saying: PingPing is the ThingKing!!

 

[dogman dan]

Yay! Send us all data, if you have a cyclanalyst. If not, just some stuff about max range max speed, and what you are riding. Let the battery break in for a week first though, it will gain about 2 ah in capacity over the first cycles. And no doubt you know to make a good box for it. At least pad it with a bunch of cardboard on the corners.

 

[swbluto]

It's been nearly new two weeks since the last informative responses. We need data!

Internal resistance, for example.

 

[pwbset]

It's been nearly new two weeks since the last informative responses. We need data!

Yes, more data! Does anyone know when the new BMS will be out that allows for graceful handling of series connections? 72v and 96v Ping needs to happen!

 

[ZapPat]

While waiting for my RMA'd elogger to get back I'll give you what info I can about my 48V 20Ah PingV2.0:

The cells seem to stay very well balanced, all within under 5 milli-volts (<0.005V) of each other after a medium distance run at average power (about 12-15km at 1C average, up to 1.75C intermitant). I think this is really good, but this is my first lithium pack so I'm not sure if it actually is.

Another test run I did yesterday was about 34kms (21 miles), the furthest I've been so far on one charge, and all went well despite some good hills and very strong headwind on the return path. End voltage after letting it sit for a while was 51.8V, so I assume that there is still a fair amount of juice in it, but not sure how much yet. Here are the cell voltages after this run, and after letting the pack sit idle overnight (no recharge at all):

3.258V
3.251V
3.256V
3.255V
3.259V
3.260V
3.251V
3.249V
3.258V
3.252V
3.258V
3.251V
3.256V
3.253V
3.258V
3.258V

So for this larger than usual run the cells are still within 10 milli-volts of each other - sounds good? And I must admit I have given this pack some hard times, but have not brought it down to the low voltage cutoff yet. I'll post more when I get my logger back from Eagle Tree. I'll do a complete discharge test down to LVC, and will post the discharge graph and the pack's measured capacity.

 

[dnmun]

when you run it down to LVC, will you try to keep track of the voltage to the BMS at that point, and if it was changing rapidly or still in the flat part?

you could actually test the internal resistance for us too if you can record the voltage at several different load regimes. will your motor draw 60A? that would be 3C for your 20Ah battery, and we could compare that to a 1C rating of about 10A and by comparing the voltage on the battery under those 2 different loads, we will know where the internal resistance number for these batteries should be. i guess the high load would be a hill and the low load would be pretty flat, those two voltage and current measurements will help a lot.

how many are considering using the BMS diy build kit from gary? even if the ebay prismatic cells are cheaper, isn't the LVC on each individual cell worth the build? then we could be comparing the performance of the ebay batteries to mr ping's packs too, as well as the a123 and lifebatt tests. i would think that the hassle of reversing a cell inside the duct tape pouch in terms of work makes it worth the hassle of building the open source BMS.

i say this because it seems to me that the nature of the vibrations for the pack in a bike may be better absorbed hydraulically by the pouch versus structurally suspended through the end crimp joints of a cylindrical cell. i saw that the first headway packs with the threaded cap are failing and i think the stiff attachments of one to another only by that screw is damaging them in the cap structure, but that is still unclear because of other factors associated with that specific pack. i am waiting for jozzer to build a headway pack with the new threaded cells to decide more.

 

[swbluto]

how many are considering using the BMS diy build kit from gary? even if the ebay priusmatic cells are cheaper, isn't the LVC on each individual cell worth the build? .

Ping's batteries seem to be built such that you have 2-5 parallel groups(To make the necessary AH) which those parallel groups in turn are attached in series to make up the required voltage. Ping's current BMS provides individual LVC to each parallel group, so if one of the cells starts to hit the dust, you'll notice it in the complete discharge test. I did. (It was the 7.1 AH from the 10 AH nominal that tipped me off.) So, effectively, there's "individual LVCs" for all practical purposes, though its accuracy is a bit less for modestly weak cells and for larger parallel groups(I.e., larger AH packs).

I'm actually guessing on Ping's construction for the larger AH packs, but mine follows that description with the same BMS as ping 2.0.

Hey, what are we going to call the new pack version with the new BMS? Ping V 2.5?

Thanks for the information ZapPat! It's nice to see how they stay so balanced(How many discharge cycles do they have on them and at what average DOD?). I'll be looking forward to the discharge test for capacity. :wink:

 

[Microbatman]

Any test data about these batteries?

How do they hold volts under load?

Anyone tested em?

 

[ZapPat]

Here's a post of mine from a while ago in case it might be usefull to anyone:

------------------------
I have one of Ping's new 48V 20AH packs, and I tell you that for "cheap" lithium, this guy is your doctor to go to for an uplift! So far I've pulled 35 amps out of it while riding up hills and accelerating, with no problems at all. Very slight heating of the cells, and a bit more heat coming from the cutoff FETs on the BMS, and very little voltage sag: 0.13 Volts per Amp of current drain. This puts Ping's Ver2 packs them slightly ahead of Headway's offerings, who are not seeming to live up to thier specs so far.

I have yet to drain them over 10Ah yet, so only half capacity used so far. Even after this, the voltage was still around 52V unloaded! The minimum voltage point logged during this trip was 47.9V while drawing about 35.5 Amps, or about 1700 Watts. So far I'm very satisfied! I've boosted a small scooter I have been given, and it seems I will be able to go about 40km if the battery lives up to it's claimed capacity (yet to see).

I've charged the battery at 6 amps using a vicor DC converter and the pack stays cool to the touch - but the BMS doesn't! It's only the protection FETs at the end of the BMS heating up, but not badly since I can touch them without discomfort. Works great! I'll post some discharging and charging curves I've logged on the ping v2 thread later.
-----------------------------------

I still won't have my logger back for another week yet, so you'll have to wait a while for the discharge graphs.

Since I measured 0.13 Volts per Amp of current drain, this gives about 130 milli-ohms of DC resistance total for the pack. The BMS FETs are about 24mohms each, and 4 in parallel, so about 6 mohms for these, leaving 124mohms for the cells. I will see if this gets better after breaking the pack in, since I've used it a bit since then (around 20 cycles with 50% DOD average).

 

[dogman dan]

I suspect the charge limitation on ping packs is related to the bms. Wouldn't you think 1 c charging would be no problem, 20 amps on a 20 ah pack, if you had the right bms to charge through?