Ping 48v 15Ah real world current ability

[alfantastic]

I'm going to purchase a Ping 48v 15Ah battery for my summer build.
I would ultimately like to couple it to a 45A controller, and wondered if anyone in the community has had experiences with this battery at this kind of current drain.
It would only require the full 45A from the battery for up to 1 minute, with a nice rest in between.
The specs are shown below.
I see that it is capable of delivering 60A, but then it shows a cut-off protection at 40-50A???
I have no doubt the battery can deliver the maximum current, but don't want to end up with the BMS shutting down trying to protect the pack.
Has anyone drawn high currents from this pack set-up without any problem?

48V 15AH V2.5 LiFePO4 Battery Pack
Max Continuous Discharging Amperage: 30 Amps
Maximum Discharging Current: 60 Amps
Discharging Cut-off Protection: 40-50 Amps

 

[dogman dan]

Your plan is garanteed to fail. Use a 15 ah ping on up to 25 amp controllers.

45 amps will kill it. Perhaps very fast, but sometimes people do get a really good set of 64 cells with zero weaklings and run a 20 ah pack on a 40 amp controller a suprisingly long time. But for every one of those, there are several that kill a ping running a big controller in less than a year.

Only needs this for one minuite? What is it, a drag race? You want to start reading away the next few weeks of all night in the lipo section.

Or at least start looking at a 20 ah pouch cell A123 pack from here. http://www.emissions-free.com/

I did some racing, where I took a 48v 15 ah ping and hit it with 13, 30 amp spikes per lap for 12 laps. Discharging only about 6 ah, it was still sagging like crazy from all the amp spikes. When I charged it, it was crazily out of balance, and took forever to return to normal. The pack was very new btw, about 20 cycles. Pings cells just can't hack big amp spikes. They can do it, but they don't handle it well at all.

 

[alfantastic]

Thanks for your reply dogman.
I did chuckle when you mentioned drag racing
I have a couple of hills to climb, where it would require the maximum current draw for no longer than a minute.
The rest period is the gentle slope on the other side.
I'll take your advice and use a 25A controller, as I don't want to cook the battery, and they aint cheap
As for drag racing...... Mmmmmmmmmm, now there's an idea.

 

[dogman dan]

Or limit amps with a CA if your big controller has a CA plug.

For hills, I recomend choosing the right motor winding. For instance, don't get the crystalyte HS model, choose the HT model.

My favorite hill motor is the 9 continent 6x10 winding. Very slow, but climbs hills up to 15% on 48v 20 amps. Typical windings tend to be limited to about 10% grades. You will see amp spikes with a 25 amp controller, but only for short enough duration that you don't pop the bms.

If you like gearmotors, get the 8t mac or the 10 t. Don't go for a 6t for hills.

There are some racers here. Hunt down Live for Physics videos some time. The shoe flying as a guy wheelies off his bike is hilarious.

 

[alfantastic]

The MAC 10T from Cellman is on the top of my list, and I was going to get his 45A controller, but wasn't sure if the Ping was up to these kind of current draws.
He sells a 30A controller, which may be a nice compromise between performance and battery reliabilty.
When a controller is marked as 30A, does that mean that it definitely won't allow current draw past this figure, or can it still spike beyond this?

 

[neptronix]

Let me add that exceeding 2C is never good on the pings. ( that would be 30A on a 15AH battery )
Over a long period of time, you will damage those cells, they will puff, and die on you in a year or two. These batteries can last quite a long time if ran a bit under spec!

48V on an 8T MAC will do about 30-32mph on a 26" wheel. It will want 20-25A constant. When you hit a hill, it will want over 30A to keep the speed up, so on 25A, you'll be dropping speed rapidly unless you weigh in the mid 100lbs . That's pushing it for a 15AH ping battery.

All the controllers he's sent me run at a bit higher amps than advertised. If you want the ping battery to last the >1000 cycles you pay for, it would be best for you to get a 20AH ping, or investigate into something with higher discharge if you don't really need the range.

20AH is wonderful on the 8T though. On 36v, if i pedal along, i can get a bit over a 30 mile range. That's the mark where range anxiety starts to fade away

So my recommendation to you, if you want a ping.. 20AH 48v.. 12FET controller.. dial the amps down to 35A with a programming cable, which is OK since you'll only be drawing that on hills or from a dead stop.. and have a ball.

 

[dogman dan]

30 amps would be the upper limit. Bear in mind, say your motor has a 30 amp controller and a top speed of 25-30 mph. Well at top speed, not into a headwind, there is simply no way that motor will be drawing 30 amps. 15-20 amps cruising is likely.

What will be happining in a case like this, is the motor will try to pull 30-40 amps in the first foot off a stop sign. This will happen for an instant, then the controller will cut it back to 30 amps max. As you get going to say 10 mph, the motor will spin up to an rpm where it does not need all 30 amps anymore, and amps will continue to back down till you arrive at the amps needed to cruise full speed.

So on the flat, you could push a 15 ah ping to a 30 amp controller. Nevertheless, the advice to upgrade to 48v 20 for a 30 amp controller is sound advice. You have a big hill. And up that hill, the motor may well pull 2c for a full minuite. Much better to lowe that c rate for a set of ping cells. Get a 25 amp controller if possible.

How tough is this hill anyway? 48v 20 amps is going to get you up 10% grades just fine. You won't have to have more power.

The other solution is obvious. Get your battery from cellman. His battery has a much higher amp rate. Then run the big controller all you want. Cellmans 48v triangle battery is superb.

 

[Doctorbass]

Maybe i could give you my own experience with the ping 48V 15A signalab v2.5 battery.

Back in 2009 i ordered 7 kit ( battery + 5A charger) from ping.

All those was used on 48V 35A stock Crystalyte digital controller and a 9C 2807 motor that was reaching 50km/h on 26" wheel

The C-A was recording burst Amax of 58A sometime and during acceleration the max sustained power was around 2500W wich is around 45A. ( I had Fluke calibrated all controller shunt as well)

We never had any problem with any battery due to this poweer usage over all 7 battery.

We only got 2 problems due to the charger that cut ( It was the input surge supressor on the Ac line) and Ping sent us 2 replacement cahrger. And one problem with one of the BMS charging mosfet that blew. Ping sent me 2 replacement BMS ( one for replacement and one for prevention as i requested) all this without any extra fee.

3 years later these battery still work great.

Maybe a great advice that could help is to disconnect the 16 pins cell connector from the BMS during storage of the battery. this will keep all cell balanced and will not drain current to the cell 1 to 4 like it usually do to power the BMS

Doc

 

[dogman dan]

You are the exception to the rule. One question I have always had with your bikes is how hard do they really get used? How many cycles, how deep are the cycles, and what does the CA say thier real world c rate is? I could put a 10 ah ping on my wifes bike, give her a 100 amp controller, and I garanfrockingtee you she would never exceed 10 amps, ever. So no problemo.

I tend to make recomendations based on my real world use, which could well be considered destruction testing.

I can only assume the guy asking could well be climbing a hill as big as mine. He could easily be doing so, untill we get him to cough up the real data on what his ride is like. We need to know length of ride, how often stops are required, speed he'll be riding, does he pedal at all, does he pedal to start off, how much does he weigh, will it be upwind one way, will it be uphill upwind, how long is the hill, what is the grade of the hill, and how cold or hot will it be?

I can only say, ignorant of answers to all those questions, that my general advice is to not use a 15 ah ping with controllers bigger than 25 amps. If you look at Pings recomendation, mine will actually exceed his.

But in the end, what amps the controller is potentialy putting out means nothing. What matters is what the rider actually uses, depending on how and where he rides.

 

[alfantastic]

Thank you very much for everyones, clearly experienced replies.
There's only really 2 big hills, approximately 17% each, no longer than 100 metres long. Maybe not big to some :lol:
I always intend to add plenty of human effort on these.
My ultimate goal is to provide good assistance, but without popping the BMS halfway up.
According to the ebikes.ca simulator, I've gestimated that the motor shouldn't need any more than 19A on the flat.
So the battery will be getting a fairly mild beating, most of the time.
Can anyone point me to a thread that explains motor windings and relation to speed/torque, please. Thx.

 

[Russell]

Ping was offering a higher power battery to those customers who asked, I think he called it "version 3". Don't know the price for them but it used much better cells.

DOC, I thought you got these (????)


-R

 

[neptronix]

30 amps would be the upper limit. Bear in mind, say your motor has a 30 amp controller and a top speed of 25-30 mph. Well at top speed, not into a headwind, there is simply no way that motor will be drawing 30 amps. 15-20 amps cruising is likely.

On the 8T MAC motor on 26" @ 36v, i cruise at 15-20 amps. 48V is going to be higher like i said. Above 20A constantly on the flats.

What will be happining in a case like this, is the motor will try to pull 30-40 amps in the first foot off a stop sign. This will happen for an instant, then the controller will cut it back to 30 amps max. As you get going to say 10 mph, the motor will spin up to an rpm where it does not need all 30 amps anymore, and amps will continue to back down till you arrive at the amps needed to cruise full speed.

The 8T MAC is an amp hungry motor and does not respond like this, it basically eats the maximum amperage your controller can provide until it hits the loaded speed. It is not like your high turn count DD motors. It is not like my slow wind magic pie either.

How tough is this hill anyway? 48v 20 amps is going to get you up 10% grades just fine. You won't have to have more power.

Maybe on your low turn count direct drive motor, but not the MAC. To maintain the speed needed at 36v, my 8T MAC needs 36-40A constant to keep up 24-26mph. On 48v, that figure is even higher. Otherwise, you drop speed rapidly, then drop out of the efficiency band of the MAC motor, and just make waste heat. If we were talking about a 10T or 12T MAC, the amp figures would be lower.

The other solution is obvious. Get your battery from cellman. His battery has a much higher amp rate. Then run the big controller all you want. Cellmans 48v triangle battery is superb.

The A123 battery would be a good choice here.

 

[neptronix]

According to the ebikes.ca simulator, I've gestimated that the motor shouldn't need any more than 19A on the flat.
So the battery will be getting a fairly mild beating, most of the time.
Can anyone point me to a thread that explains motor windings and relation to speed/torque, please. Thx.

You picked the wrong motor.

Select the BMC_V2Spd.
Change the controller to the 40A unit.

The speed is approx. 30mph and the amp draw at cruise is 27 amps.
Run it on the 20A controller and you will lose 3.2% of your efficiency due to not feeding it enough amps. And you drop 3mph.

Hit a hill and the amp requirement increases massively, and if you do not feed it enough amps, you lose tons of speed, like 10-15mph of speed, verging on stalling. Adding pedal power helps a lot here, but a hot motor and lower range due to lower efficiency is not ideal.

The 10T motor plus 48v will do about 24mph, require less amps on a hill ( due to lower speed ), and have a lower amp draw while cruising, about 14A. This would be OK to use with a 15AH ping.

The 10T MAC is equivalent to the BMC torque motor.

 

[alfantastic]

Whoops, my bad.
I used the BPM 36v 500w @48v, assuming coz it had the same wattage and top speed, it would be fairly similar.
Things are never simple, except me :wink:

 

[Doctorbass]

You are the exception to the rule. One question I have always had with your bikes is how hard do they really get used? How many cycles, how deep are the cycles, and what does the CA say thier real world c rate is? I could put a 10 ah ping on my wifes bike, give her a 100 amp controller, and I garanfrockingtee you she would never exceed 10 amps, ever. So no problemo.

I tend to make recomendations based on my real world use, which could well be considered destruction testing.

I can only assume the guy asking could well be climbing a hill as big as mine. He could easily be doing so, untill we get him to cough up the real data on what his ride is like. We need to know length of ride, how often stops are required, speed he'll be riding, does he pedal at all, does he pedal to start off, how much does he weigh, will it be upwind one way, will it be uphill upwind, how long is the hill, what is the grade of the hill, and how cold or hot will it be?

I can only say, ignorant of answers to all those questions, that my general advice is to not use a 15 ah ping with controllers bigger than 25 amps. If you look at Pings recomendation, mine will actually exceed his.

But in the end, what amps the controller is potentialy putting out means nothing. What matters is what the rider actually uses, depending on how and where he rides.

All 7 packs kits was with version 2.5 BMS and i only asled Ping for the BMS that can take 40A continuous and to add fiberglass sheet on all sides for the battery on special request wich he did perfectly.

These ebikes was for my familly and on all those i would say that 60% that are for men are used at their full potential ( My uncles saw my ebikes and are expecting to get good performance and good off road and hill and WOT) as well 8) The 40% are their wifes and kids. and as well have a bit lesss WOT and hill and offroad.

They use them all 3 seasons except winter where they store them and keep the battery in my recommendations for storing.

My uncle keep the battery in the 80% use like i recomanded but sometime they 100% empty them accidently as well. but they rebalance no prob.

I also had installed 40A 32v car fuse in serie with the battery and the fuse contact are melting on some wich usually happen when 35-40A up to 60A current are draw.

Their C-A indicate between 15 and 35Wh/km average as they said.

I also tested personally all these battery at 2000W continuous with a high power resistive load of around 1.3ohm before to let them to use them and recorded their Ah and Wh. All was above 15Ah and 728Wh on arrival.

Doc

 

[gensem]

Ping is sold as a 2c battery mainly for two reasons.

The mosfets on the BMS ll overheat if you try to push over 40a for some time. (Heatsink anyone?)
The cells do take 3c-4c without sagging much until you have 75-85% of the charge depleted, after that the battery does get very HOT and ll sag alot and ll probably hurt the pack.
Im not saying that you should run it on 4c nor that it has to be 1C.
Im just imagining that Ping rates it low to avoid returns and if something has to fail let the BMS fail first, which is cheap and easy to replace.

Either way I cannot say much about lifetime running higher C, I got the lipo virus and im not using my ping anymore.
Try to get a higher C battery like A123, most people around here outgrow small motors in a week and the fun stuff needs much more current.

 

[dogman dan]

That's some outstanding results Doc. I know of some others that have seemed to get away with murder, running a 5304 at 40 amps on a 20 ah ping. Pretty amazing, and definitely better than the typical results when people run a headaway hard at it's max specified c rate. Shows that QC is very good at pingbattery. One runt cell like is typical of fleabay batteries would not have stood that.

But I'll still stick to recomending A123's or lipo for people that want 45 amps. Nothing wrong with a few bursts of 2c on those hills. I just can't bring myself to say, " get a ping for 45 amp controller though" 30 would be fine, particulaly since the majority of the ride is flat.

Neptronix, please tell me you aren't seriously recomending a fast winding BMC for a 17% grade hill.

I think you misundersood me. I never said a " normal typical" hubmotor winding will climb 10% efficeintly. Just that it can without overheating immediately. On 17% grade, it better be a very short hill. 2 miles of it would kill typical kit motors.

Nice thing about short hills is you can charge 3/4 of it on momentum. So you might not want to go to too slow a winding. Hit that hill at 25 mph for sure.

 

[neptronix]

I did misunderstand that we were talking about the 8T here. It's an awful choice for the job. Then you misunderstood that i was recommending the 8T.

Double K.O.
Anyway we can both agree that a slower wind, like something that does 20mph on 36v, would be best, yah?

 

[dogman dan]

Definitely. You suggested a BMC motor, that I was thinking was closer to 30 mph on 48v.

17% Ughh. That better be a short hill. My super slow winding dirt bike motor at 72v would struggle with that if longer than half a mile.

 

[neptronix]

Nah, i said the MAC/BMC would do a little over 30mph, which would be unsuitable and eat amps for breakfast. The next post down i said the 10T would be best. Where i missed things is that i thought the OP was looking at an 8T MAC/BMC motor, so that's my bad.

Also, you ought to try out the magic pie.. torque central, dude . I think it would be better for your application. It sure as hell can handle some continuous wattage. If you run 72v, it would be perfection for you.

 

[El_Steak]

My experience is similar to DoctorBass. I ordered a 48V 15ah v2.5 pack from Ping in 2009. I ordered my pack shortly after doctorbass and got the same BMS and the PCB sheets.

I first used it with the standard ebikes.ca 20 amps controller but quickly upgraded to the 35amps controller (same as doctorbass). The 35 amps controller would spike to 40-45 amps under hard acceleration/hill climbing so I added a limit in the cycle analyst to force it down to 35 amps.

I used the pack for a season and then sold it to a friend when I went LiPo. Last I heard, he still uses it to commute to work almost every day (spring, summer and fall) and has had no issue with it. He uses a 40amps controller with the same 35amps limit on the cycle analyst. He uses it with a 2805 amp hungry motor and he rides full throttle all the time.