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48V 20Ah lifepo4 lasts only 34 km on 5th cycle
- Thread starter Nicoist
- Start date
Hi,
I've got the same set-up; 1000 GM w/ping 48V 20Ah and I can go an easy 25 miles with no pedaling. The un assisted top speed is 28+ mph.
You might try checking all the electric connections as it seem something isn't right.
Nick
I've got the same set-up; 1000 GM w/ping 48V 20Ah and I can go an easy 25 miles with no pedaling. The un assisted top speed is 28+ mph.
You might try checking all the electric connections as it seem something isn't right.
Nick
dogman dan
1 PW
Battery bought from who, and what does is weigh? There are some rumors of packs that are 14 ah selling as 20's. In other cases I have heard of, round cell 18650 packs have only delivered 14 ah out of a 20 ah pack when used at ebike discharge rates. Usually by the 4th charge the pack is taking all it can or nearly so, but are you leaving it to charge awhile, or unplugging it the instant it goes green light?
It also depends on your terrain. If it's nearly ideal, then you should see more. But if you're climbing up hills or are heading into noticeable headwinds, that distance might not be unexpected. I've also heard that it takes some cycles to get a "full battery charge", so wait until the 10th before panicking.
More technical info would be helpful, like how much Ah your battery has discharged. The CA typically does this as do other meters, but I understand the golden motor doesn't come with that as a default option.
More technical info would be helpful, like how much Ah your battery has discharged. The CA typically does this as do other meters, but I understand the golden motor doesn't come with that as a default option.
Yes I see. I get 34 km with some pretty good pedaling and all flat street terrain, only going top speed ocasionally. The pack weighs 10 kg. I got it from cammy from ebay. I feel like it has much less than 20Ah. I remember seeing a thread where there was a cammy pack cammy opened, it had round cells, which seemed to be disliked. So it probably has those.
No I wouldn't want the cycle analyst, so expensive and too big for me (got me a cheap speedometer for 9,- that's cool)
I will get me a Multimeter and figure out the real Ah myself... Then I'll probably get in contact with the seller and make a paypal dispute out of this because I don't really like to get punked. It should provide 20Ah if it says 20Ah, at least is should be close to it...
Then I might get me a good new pack. Seems like ping is the only way to go at reasonable price, isnt it?
I remember I was wondering why the 48V 15Ah pack also weighed 10Kg. It's probably the same battery!!
thanks all
greetings
nicolai
No I wouldn't want the cycle analyst, so expensive and too big for me (got me a cheap speedometer for 9,- that's cool)
I will get me a Multimeter and figure out the real Ah myself... Then I'll probably get in contact with the seller and make a paypal dispute out of this because I don't really like to get punked. It should provide 20Ah if it says 20Ah, at least is should be close to it...
Then I might get me a good new pack. Seems like ping is the only way to go at reasonable price, isnt it?
I remember I was wondering why the 48V 15Ah pack also weighed 10Kg. It's probably the same battery!!
thanks all
greetings
nicolai
voicecoils
1 MW
Could be 15ah yes...
My two Headway lifepo4 packs can be configured as 36v20Ah. Together they weigh 9.4kg as a comparison. They're made of 24 cylindrical 10ah cells each.
Also, a multimeter will not help you determine amp hours or watt hours delivered by the pack. You need something that is monitoring both current and voltage simultaneously then logging them and computing the energy delivered. The Cycleanalyst does this, so does the WattsUp and DocWatson (powerwerx.com, if you don't want the convenience and extra bicycle features).
My two Headway lifepo4 packs can be configured as 36v20Ah. Together they weigh 9.4kg as a comparison. They're made of 24 cylindrical 10ah cells each.
Also, a multimeter will not help you determine amp hours or watt hours delivered by the pack. You need something that is monitoring both current and voltage simultaneously then logging them and computing the energy delivered. The Cycleanalyst does this, so does the WattsUp and DocWatson (powerwerx.com, if you don't want the convenience and extra bicycle features).
voicecoils said:
Depends on the user's sophistication. If he's measuring the current(assuming he can measure that much battery current with his multimeter), then he can estimate by doing some pseudo-integration in his head. I.e., "I was running 30 minutes at 10 amp average and 30 minutes at 15 amp average. The means I was running at .5*10+.5*15=12.5 amp-hours".
Wouldn't be accurate, but it should be able to tell whether or not it's even close to 20 ah. At 20 wh/km maximum , then 34*20 =680 wh which is no-where near the theoretical ~960 wh a 48v20ah should be getting, so it seems a fairly crude measurement should be able to tell.
dogman dan
1 PW
Hmm. weight sounds about right for a 20 ah, but the range sure should be longer. Are you sure you are leaving it charging enough to fully balance it? If not, it may have arrived with some dead cells, which would lessen the range a lot. Darn, this is the first I remember seeing of a problem with a new Cammy pack.
Yes that is exactly what i was gonna do. I'll measure the amperes (the multimeter I get can measure up 10A) during idle run (the wheel not touching the ground) and then leave the bike running fulll speed with a fully charged battery with free wheel and see how long it takes until it cuts off. Then I can determine the Ah, should be very accurate this way.
Hmm no I usually don't leave the batt charging much more when the red light turns into green.... should I?
The battery has about 52V after full charge and about 45 when it's empty, at cutoff.
So the average figure is 48,5 V, so it should be accurate if I use 48,5 V for calculating the Ah.
Yes the cycle analyst is a nice tool actually, but it's hard and expensicve to get it here in europe...
thanks for your help!
greetings
nicolai
Hmm no I usually don't leave the batt charging much more when the red light turns into green.... should I?
The battery has about 52V after full charge and about 45 when it's empty, at cutoff.
So the average figure is 48,5 V, so it should be accurate if I use 48,5 V for calculating the Ah.
Yes the cycle analyst is a nice tool actually, but it's hard and expensicve to get it here in europe...
thanks for your help!
greetings
nicolai
Hi
Sounds like a 15ah pack, could also be low voltage cutoff on a bad cell tripping out as well, I wouldnt do a no load test to check the pack capacity, it will take ages and it wont really prove much as you may get much more AH out of the pack at small C rates, you say you didnt want the CA because of its size but would rather use a multimeter :? you really just need a watts up meter, they are 40 dollars and small like a box of matches, this will tell you your min voltage, max amps, power consumed in watt hours, nice and simple, it is useful to know this information if not when just diagnosing problems such as this.
If they have sold you a 20AH pack and it is actually a 15AH pack then you must go back to them, its early days for this stuff I think that folks should go with Ping as he seems the most reliable of the bunch at the moment and his after sales service is very good.
Knoxie
Sounds like a 15ah pack, could also be low voltage cutoff on a bad cell tripping out as well, I wouldnt do a no load test to check the pack capacity, it will take ages and it wont really prove much as you may get much more AH out of the pack at small C rates, you say you didnt want the CA because of its size but would rather use a multimeter :? you really just need a watts up meter, they are 40 dollars and small like a box of matches, this will tell you your min voltage, max amps, power consumed in watt hours, nice and simple, it is useful to know this information if not when just diagnosing problems such as this.
If they have sold you a 20AH pack and it is actually a 15AH pack then you must go back to them, its early days for this stuff I think that folks should go with Ping as he seems the most reliable of the bunch at the moment and his after sales service is very good.
Knoxie
dogman dan
1 PW
yes! You do need to leave it plugged in overnight, especially the first 10 cycles or so. By unplugging right away, the battery is not being allowed to balance!
When brand new, you need to leave it charging at all times when not riding to fully balance the cells as they break in. This could definitely cause a lot less range since the undercharged cells will be soon drained, causing the whole pack to cut off. It is also think it is a good idea to avoid riding the pack to cut off for a few cycles too. I know you are dying to know what the range is, but I think it's kinda unwise to drain the thing completely untill it gets more balanced. Hopefully the range will improve a bunch when you get more balanced. However, with some other sellers, notably mr lau, some packs have been sent out with nonfunctional cells. I hope you don't have that problem. Good Luck!
When brand new, you need to leave it charging at all times when not riding to fully balance the cells as they break in. This could definitely cause a lot less range since the undercharged cells will be soon drained, causing the whole pack to cut off. It is also think it is a good idea to avoid riding the pack to cut off for a few cycles too. I know you are dying to know what the range is, but I think it's kinda unwise to drain the thing completely untill it gets more balanced. Hopefully the range will improve a bunch when you get more balanced. However, with some other sellers, notably mr lau, some packs have been sent out with nonfunctional cells. I hope you don't have that problem. Good Luck!
dogman dan
1 PW
HMMM. I justs looked at a bunch of ebay lifepo4 sellers ads, and there seems to be some that post a 48-20 at 10 kg and others including Cammycc say 12kg for a 48v 20 ah. Something is fishy for sure if the pack weighs 10kg and the specs say it should be 12! Maybe it is really only a 18 ah pack or something. Interestingly, the mr lau, known to be unable to deliver 20 ah packs seem to also weigh 10kg.
Thanks for your input. I'll consider all yaw said.
Today I could measure the amperes in idle run, it's 1,48 Ampere. Few days ago I already tested how long is goes with wheel in air: 9,1833 hours. So that's 1,48 Ampere * 9,1833 hours = 13,59 Ah!! It's obvious that this can't be no 20Ah battery. I'll notice the seller now.... I'll keep you posted on how it turns out....
Today I could measure the amperes in idle run, it's 1,48 Ampere. Few days ago I already tested how long is goes with wheel in air: 9,1833 hours. So that's 1,48 Ampere * 9,1833 hours = 13,59 Ah!! It's obvious that this can't be no 20Ah battery. I'll notice the seller now.... I'll keep you posted on how it turns out....
:lol: While dishonesty may permeate all domains, wishful thinking had people hoping that it wouldn't be so(Especially since it seemed like an emerging competitor for roughly the same quality product, which is generally felt the marketplace needs.).
dogman said:
Hi,
We do really sorry, because of our worker's mistake, we have sent the wrong battery to this buyer, our worker sent the 48V15AH instead of 48V20AH, we do really sorry for this..
We have replied the buyer, we will help the buyer solve the problem as he/she want...
dogman dan
1 PW
Way to go Cammy. 
Unfortunately if he takes a refund on the difference in price he will then have a battery that will be used at a higher c rate than the one he chose, and will not be likely to last as long. Mistakes happen, but how come the customer couldn't tell by a label what sise battery he had? Hope you don't have a pile of mislabled packs in the mail.
Unfortunately if he takes a refund on the difference in price he will then have a battery that will be used at a higher c rate than the one he chose, and will not be likely to last as long. Mistakes happen, but how come the customer couldn't tell by a label what sise battery he had? Hope you don't have a pile of mislabled packs in the mail.
dogman dan
1 PW
Yay! and no endless resorting to paypal dispute proceess.
