looks like i am going lipo sooner than i had hoped... :(

[Diamondback]

on my ride home from work tonight, at speed (about 40km/h) on an otherwise un-lit cycle path, all my lights quit and i have no power

i looked down at the CA and it's still illuminated, but none of the characters are displayed. only the little green back-light is on.
the controller is off. i turn off the battery then back on and everything returns to normal. as soon as i turned on the cycle lumenator, everything quit again

I repeat the process a few times. i leave the lumenator off, and just reset the BMS again. i notice that as soon as i touch the throttle, it quits again (this is becoming annoying)...
reset number 3 (or is it 4 ?) i cycled through the screens on the CA and i see minimum voltage is 46.4V. at only 8.8AH. this is on a 15AH battery. ive never taken it past 10AH before.
it has only around 300 cycles on it, most of those very light at around 5-6AH only.

looks like im going to hit up Methods for a set of his lipo LVC boards shortly....

if there's anyone in the Sydney area that wants a ping v2.5 48V 15ah (8AH usable) and 5A charger, make me an offer.


im looking at zippy 6S 8000's running 2 of them in series for 49.8V FOC (i terminate the charge at 4.15V)
i think that the 8000mah will be sufficient for my future needs.

Jason.

 

[knoxie]

Thats a good thing? if you are only running a couple of packs make things easy just use lipo buzzers for your LV alarm and charge with an RC charger, nice and easy, been doing this for 2 years now with no problems 8)

 

[Diamondback]

that's my intent (at first anyway) to just run 2 6S bricks then charge them individually. assemble in series to ride.

im just a little dissapointed in the ping battery. i had thought it would last for maybe 700 cycles. not the 300 odd it has on it now.

ill go lipo as soon as my budget allows. then once i can add in the LVC boards, ill feel safer. in the mean time ill just run some lipo alarms.

Jason.

 

[dogman dan]

I'm sure you will love your lipo, but do take a peek at the ping, and see if something obvious is wrong, like a disconnected wire to the bms. Or something toasty looking on the bms itself. Only if you verify that you have dead cells is your ping toasted now.

 

[knoxie]

Hi

Well Lipo is an upgrade but it is a shame that the battery has gone south, its most likely only 1 cell thats causing the issue though, if you have just 2 packs in series on Lipo then there isn't much point running LVC alarms that monitor cell level, simple buzzer is cheap and effective, from my experience with these packs as long as you don't take them right down they stay well balanced, sure cell level LVC is preferable but its only going to catch the 1 pack in your case which would most likely be on its way regardless, the trick is to use your CA also and keep an eye on AH, you can of course set LVC in your CA too.

I started off using the buzzers and worrying about them, I only use the buzzers when on long rides, I dont use anything in the week on my commute as I never take the pack down more than half way.

You can get dual or quad channel RC chargers that make charging super simple and safe, don't go bulk charging unless you understand fully what you are doing, simple cheap RC chargers are great and work just fine, its so much better to keep things nice and simple

 

[MadRhino]

You should test each cell in your ping pack, for it could be cheap to repair and would last much longer.
Not that I disagree going Lipo, but your Ping might be useful at times.

 

[Diamondback]

ill have a look at the ping and see which cell is dead (assumption at this point) but i was thinking of going lipo anyway.
it's lighter and i usually only use 6-8ah on my longer rides so carrying the heavy 15ah ping for no real reason.

i have a Hyperion EOS 0720i SD3 charger, so i can charge 2 packs at once. so charging is a breeze.
and a 24V 41.7A power supply to run it, so i can charge at up to 20A per channel. the zippys can handle 2C charge rates.
so i can charge them at 16A, though most of the time ill just use 1C, unless im in a hurry to charge up.

those 6S 8000 zippy's im looking at are only $90 (au) each. so ill get two of those in a week or 2 and im good to go.

Edit: Update

just finished charging the ping after the ride home. all leds light up at 59.84V and 8.9ah from the charger.
looks like one or more cells has lost capacity and is only capable of 8AH or so. ill keep using it until i get my lipo's,
and monitor the voltage on the CA.

with a 12S setup, i should set the LVC on the CA at 36V (3v per cell) ? or should i set it at 38.4 (3.2V per cell) ?
3.2 would be safer i guess. ill run some 6S lipo buzzers too (on the longer rides)

Jason.

 

[MadRhino]

You don't want to discharge Lipo as low as 3.2v. I usually discharge to 3.7 and never go below 3.5, not much time left to ride after that anyway and Lipo is really happy between 3.7 and 4.15v.

 

[Diamondback]

so a LVC on the CA of 44.4V ?

that's only around 5.4V from full to empty. is that correct ?
ill also run the lipo buzzers on the longer rides.

Jason

 

[DAND214]

I don't understand why you would buy only 2 packs.

8ah is what you are usung now out of the Ping and it's not enough. So why would you just get 8000mah packs and run them to theier limit? You never want to discharge a LiPo dead.

i would get 12s4p setup and be safe than sorry.

That's just my opinion, 8Ah is not enough!

Dan

 

[Diamondback]

I will probably end up with 4 bricks. My budget wont allow more than the 2 at first.
I would probably still run them as 2 packs in series.

Minimizes the risk of connecting something wrong. And most of my rides use only around 6ah or so.
Just in the last week the weather has been really good, so I decided to ride to work. That's a 42km round trip.
I average 10 wh per km for the trip. So I need 420wh usable if I'm going to do it on one pack.

I calculate 318wh usable from 12S 8000. Allowing 80% DOD.

It means that until I get the second pair of batteries, I just have to go a bit slower.

The idea would be that I would ride to work on one set and ride home on the other.
But that has to wait. I can probably swing the first pair of batteries in about a month.
The second set will have to wait until July when I get my tax refund.

Jason.

 

[dogman dan]

Yup 44v cutoff for the RC lipo, but that's resting voltage. Once you determine what your usual voltage sag is, you can lower it just a tad more. So if you sag 1v under load, you could go ahead and run a 43v lvc. It would cut off at 43v under load, and when you stopped it should still be at about 44v.

Keep that ping topped up and unplug the bms once you are on the lipo. Later on maybe you can sell off the good cells to somebody. Or get some ping cells and fix it.

 

[Diamondback]

sounds good.

thanks for the advice / info.

Jason.

 

[Diamondback]

looks like once again, i have jumped to conclusions and it now looks like i owe Mr Ping another apology.....

i think the problem is another equally unlikely cause. something is wrong with my cycle lumenator.
tonight the BMS quit with only 4.8AH used. i was like WTF ???

then when i reset the BMS, it would light up the cycle analyst for a few seconds then immediately fade awaw to just the green
screen, no text. i did this several times, same result. i then turned off the lumenator and everything returned to normal.
i had full motive power again. rode home at full throttle around 40km/h, the BMS didn't quit once !

once i got home, resting voltage on the ping was 52.1V. at a complete stop, i turned the lumenator back on.
guess what happened next ?

52.0
51.9
51.8
51.7
51.6
51.5
51.4
51.3
51.2

power off !
bingo !
the BMS quit again with the same symptoms as before.

seems there is some kind of short or other large power drain in the lumenator causing the BMS to trip.

ill send Justin an email and ask if they have ever seen this behavior before. it's not under warranty anymore.

so as i have already pulled the trigger on the Lipo's, i will now ride the ping till the weekend to cut off
(haven't done that for a full 15A before) if i confirm that it is ok, ill try selling it locally cheap.

that will pay for a second pair of the zippy's.

if it is ok after-all, ill be asking only around $250 for the battery and 5A charger.


Jason.

 

[dogman dan]

Maybe keep it anyway and do some long tours on the weekend? Unplug the bms and it will store for a long time fine.

 

[Diamondback]

if it is ok, and it seems likely that it is, i would rather have the funds for a second pair of lipo bricks.

can't unplug my BMS anymore. as a part of my initial trouble shooting, i removed the plugs and soldered the wires
direct to the BMS. we had initially suspected faulty BMS plugs. turned out to be a dry joint on the BMS somewhere.

so once i got the new BMS from mr ping, i had no plugs so i had to solder the new one in too.

hasn't been an issue so far.
if im not going to ride for a few weeks (3 weeks or so) i just check the resting voltage and if needed
i plug in the charger for an hour or so, just to top it up again.

im looking forward to the lipo's not sagging like the ping does. even at a modest 1C it still sags lots.
the zippys i have ordered are rated at 30C, ill be drawing less than 2C from them. should have virtually
no sag at all.

if i have a second set, that will give me more than enough power for even my longest rides.

Jason.

 

[Diamondback]

update, confirmed that the battery is fine. rode home from work tonight full throttle most of the way.
combined with the ride in, i drew well over 10Ah from the battery, and not a single BMS trip.

also, Justin has given me some instructions to try to see if i can solve the lumenator issue.
if i can't get to the problem, i can send it back to them for trouble shooting.

worst case, i guess i can always run it on a separate supply independent from main power,
though that's kinda a hassle having to charge more than one battery, so i would like to avoid that if possible.

Jason.

 

[Diamondback]

guess what the post man delivered today !

my first 2 6S 8000's.....

have to order 2 more once i sell the ping.

Jason.

 

[dogman dan]

zippy 30c 8 ah. Yumm. Makes me wish I didn't have a big stack of 5 ah lipo already.

4 of those, and you have reet neat complete 44v 16 ah. Enough for most people to do anything they want. 20 to 30 mile range.

 

[docnjoj]

So what happened to the Ping/light thing? A working Ping, even if you have to fix it is really a value. I had to tear mine down 2 years ago and went from 48 volts 20AH to a 36 volt split by getting rid of bad cells. A new BMS and the salvaged cells and it is still going 2 year later. Ping makes good stuff and it is not that hard to fix them.
otherDoc

 

[Diamondback]

As far as I can tell, there is nothing wring with the ping.

The problem is with the lumenator. I'm still working with
Justin to try to get to the bottom of its issue.

I had already ordered the lipo's when I found out it wasnt
The battery that was faulty.

That's why I'm going to try to sell the ping.
I would rather have the lipo power instead of the ping.
Nothing wrong with it. Just that for most of my rides
Im using only around 6ah or so.
So I'm carrying the 15ah battery when I don't really need to.

And I would rather see the ping go to a good home with someone
That really will use it.

Jason.

 

[Diamondback]

Update.

went for my first ride today under lipo power.

some interesting observations from a first time lipo user....

according to the CA, i drew 3.5ah of the available 8ah. so i should have had batteries that were just over 50% SOC
at the end of the ride.

testing with my cell checker once i got home reveals that there is less then 50% ?

pack data from the end of the ride.

pack 1

c1 3.808
c2 3.807
c3 3.807
c4 3.811
c5 3.813
c6 3.809

delta 0.006

22.86 V total
37%


pack 2

c1 3.814
c2 3.813
c3 3.813
c4 3.818
c5 3.816
c6 3.815

0.005 delta

22.88 V total

38%


45.74 pack total voltage at the end of the ride.
voltage at the start of the ride was just on 49.7V

i don't know what to believe. the cell checker of the ah drawn on the CA ?

it is interesting to note the very different discharge curves of Li-Po vs LiFe
the LiFe pack would remain at a fairly constant voltage for the entire ride, only sagging a little under load.

while the LiPo doesn't sag like the LiFe does, it's voltage does not remain a constant at all.

can someone please help me to understand these numbers ?

Jason.

 

[sn0wchyld]

Update.

went for my first ride today under lipo power.

some interesting observations from a first time lipo user....

according to the CA, i drew 3.5ah of the available 8ah. so i should have had batteries that were just over 50% SOC
at the end of the ride.

testing with my cell checker once i got home reveals that there is less then 50% ?

pack data from the end of the ride.

pack 1

c1 3.808
c2 3.807
c3 3.807
c4 3.811
c5 3.813
c6 3.809

delta 0.006

22.86 V total
37%


pack 2

c1 3.814
c2 3.813
c3 3.813
c4 3.818
c5 3.816
c6 3.815

0.005 delta

22.88 V total

38%


45.74 pack total voltage at the end of the ride.
voltage at the start of the ride was just on 49.7V

i don't know what to believe. the cell checker of the ah drawn on the CA ?

it is interesting to note the very different discharge curves of Li-Po vs LiFe
the LiFe pack would remain at a fairly constant voltage for the entire ride, only sagging a little under load.

while the LiPo doesn't sag like the LiFe does, it's voltage does not remain a constant at all.

can someone please help me to understand these numbers ?

Jason.

i'd say you'd used a bit more than 3.5 ah, but not a whole lot. the 8 ah will be from 4.2 to 3.0 volts, so dont expect more than about 6ah out of your pack if you're beeing conservative with your charging... (4.1-3.6 or 7).

what does your charger say its putting into the pack? this will let you know if the CA is off with its numbers
how many cycles have you put on the batts before installing em? capacity usually improves over the first doezen or so cycles.
and how cold was it? as they all suffer capacity loss when its cold out (I notice a big difference from mid 20's to mid teens).

 

[Diamondback]

this was the first cycle of any kind on them. temperature today was a little cool but not too much.
i think most of today was around the 17c-19c range.

my charging regime with lipo (even my RC car and boat ones) is to terminate the charge at 4.150V per cell.
i have the LVC on the CA set at 42V (3.5V per cell).

i am currently charging them to storage only at the moment, it will be a few days until i will ride the bike again.

so i should figure on 6ah useable on the batteries ?
guess that makes much more sense with the numbers i saw on the cell checker.
no way am i going to let them get to 3.0V per cell or less. 3.5V is low enough.

thanks for the info.

edit / update....

storage charge completed.
according to the charger it delivered 2023mah & 2095mah respectively and the batteries are now back on 67%


Jason.

 

[sn0wchyld]

this was the first cycle of any kind on them. temperature today was a little cool but not too much.
i think most of today was around the 17c-19c range.

my charging regime with lipo (even my RC car and boat ones) is to terminate the charge at 4.150V per cell.
i have the LVC on the CA set at 42V (3.5V per cell).

i am currently charging them to storage only at the moment, it will be a few days until i will ride the bike again.

so i should figure on 6ah useable on the batteries ?
guess that makes much more sense with the numbers i saw on the cell checker.
no way am i going to let them get to 3.0V per cell or less. 3.5V is low enough.

thanks for the info.

edit / update....

storage charge completed.
according to the charger it delivered 2023mah & 2095mah respectively and the batteries are now back on 67%


Jason.

yep, sounds like the ca is off by a bit, and that is kinda cold... I'd suggest cycling the batteries on the charger another couple of times... using lipo straight out of the bag is a bit risky. If there's something wrong in the cell then there's a good chance it'll start to show its ugly head in the first few cycles (not a guarantee, but its good practice none the less). Doing these cycles on the charger is a bit safer than doing it between your legs on a bike...
Its good to discharge the pack without balancing (if you're charger does that at all). that way if any cell is drastically weaker/stronger than the rest it will show clearly by the time the pack is empty.

personally I have my CA set to 3.65volts. You can always put it a bit lower if you need to 'limp home' but I found that with all the packs I've bought their balance starts going way out below 3.65v. keeping them above this is good for cycle life and charge times (less time balancing).

hope that helps mate. and welcome to the dark side...