patrick_mahoney
100 W
First off, I have no affiliation with anyone in the E-bike business.. I'm just a guy who likes electric motors and bicycles.
I bought a 48V 15Ah Lithium Iron Phosphate battery from Ping via his website last year in May 2009. Since then I've ridden something around 120 commuting trips along my 6 mile corridor to work, and I've recharged the pack around 25-30 times. I usually didn't let it get too low between charging cycles, except winter when I stored it at about 60% charged (ish). My commute is about 12 miles roundtrip but I also use my e-bike for grocery shopping and general errands.
Over this last summer I added a CycleAnalyst to my e-bike and now I can track battery capacity. My e-bike is an REI Marin hybrid with a rear-drive 9Continent M2807 on a 700C wheel, and an Infineon 25A (C3625) controller with regen enabled.
First off, the caveats.
1. I used a clamp ammeter to calibrate the CycleAnalyst. Accuracy on the clamp ammeter isn't fabulous - but it should be within 1%, I'd think.
2. I used the GPS on my iPhone to calibrate the CycleAnalyst. Accuracy on my iPhone GPS isn't great either, and I sort of did a trial-and-error approach to the Cycleanalyst values. But the end result should be close to measured.
3. I have bicycle headlights which are driven off the main pack, but they split off before the current measurement so they are an invisible drain.
4. though the screenshots show a lovely 48V, it actually cuts off if you pull more than 100W out of the battery. It's drained to the cut-off even though it doesn't look like it when you see the resting voltage.
On my most recent trips I drained the Ping battery to cut-off, my CycleAnalyst read:
16.9Ah
with 0.5A back in from regen (2.9% for the curious)
and, not that it's relevant, but my average speed was 15.5mph and total distance travelled was 54.8miles (I pedal too).
The obvious question is, what did my CycleAnalyst read when I first got my Ping battery, but unfortunately I only bought my CA box this spring, so I don't have the out-of-box measurements for my Ping Battery that match apples-to-apples. I do have a drain test that I did with a clamp ammeter on my test bench using a different motor and a different controller that measured 16.7Ah before cut-off back when the battery was brand new.
Still I'm showing a drop in current capacity of 16.9 -0.5 = 16.4Ah vs. 16.7Ah measured when the battery was new. So a drop of 3% capacity over 16 months, and roughly 27 charging cycles. Not at all bad.
While I'm impressed with the battery, I was not at all impressed with the charger that Ping included. It was prone to overheating when I first got it but then the fan died on it about 6 months later, so finally I replaced the tiny (dead) fan with a bigger computer fan and replaced the stock plastic cover with a larger vented metal container.
Patrick Mahoney
Fort Collins, Colorado
I bought a 48V 15Ah Lithium Iron Phosphate battery from Ping via his website last year in May 2009. Since then I've ridden something around 120 commuting trips along my 6 mile corridor to work, and I've recharged the pack around 25-30 times. I usually didn't let it get too low between charging cycles, except winter when I stored it at about 60% charged (ish). My commute is about 12 miles roundtrip but I also use my e-bike for grocery shopping and general errands.
Over this last summer I added a CycleAnalyst to my e-bike and now I can track battery capacity. My e-bike is an REI Marin hybrid with a rear-drive 9Continent M2807 on a 700C wheel, and an Infineon 25A (C3625) controller with regen enabled.
First off, the caveats.
1. I used a clamp ammeter to calibrate the CycleAnalyst. Accuracy on the clamp ammeter isn't fabulous - but it should be within 1%, I'd think.
2. I used the GPS on my iPhone to calibrate the CycleAnalyst. Accuracy on my iPhone GPS isn't great either, and I sort of did a trial-and-error approach to the Cycleanalyst values. But the end result should be close to measured.
3. I have bicycle headlights which are driven off the main pack, but they split off before the current measurement so they are an invisible drain.
4. though the screenshots show a lovely 48V, it actually cuts off if you pull more than 100W out of the battery. It's drained to the cut-off even though it doesn't look like it when you see the resting voltage.
On my most recent trips I drained the Ping battery to cut-off, my CycleAnalyst read:
16.9Ah
with 0.5A back in from regen (2.9% for the curious)
and, not that it's relevant, but my average speed was 15.5mph and total distance travelled was 54.8miles (I pedal too).
The obvious question is, what did my CycleAnalyst read when I first got my Ping battery, but unfortunately I only bought my CA box this spring, so I don't have the out-of-box measurements for my Ping Battery that match apples-to-apples. I do have a drain test that I did with a clamp ammeter on my test bench using a different motor and a different controller that measured 16.7Ah before cut-off back when the battery was brand new.
Still I'm showing a drop in current capacity of 16.9 -0.5 = 16.4Ah vs. 16.7Ah measured when the battery was new. So a drop of 3% capacity over 16 months, and roughly 27 charging cycles. Not at all bad.
While I'm impressed with the battery, I was not at all impressed with the charger that Ping included. It was prone to overheating when I first got it but then the fan died on it about 6 months later, so finally I replaced the tiny (dead) fan with a bigger computer fan and replaced the stock plastic cover with a larger vented metal container.
Patrick Mahoney
Fort Collins, Colorado
