Hi All,
I've got a MagicPie5 laced up in 29" mountain bike wheel with a 52v lithium battery. Have had a ton of fun with this setup. It's been reliable and consistent in it's power delivery for 3 years. Recently, it seems like the controller won't put power down above a certain speed.
I usually see about 700-1100watts at full throttle above 12mph, tapering off to 650 as the bike climbs up to 27mph.
Recently, the system has been very cleanly and smoothly tapering off and holding 12mph at about 350 watts with throttle at full position. Throttle response is clean and smooth, no jitters. Any percussive or other kind of troubleshooting manipulation of the throttle provides the same results..
Clean and smooth control of power delivery that tapers off as speed reaches 12mph as if the throttle signal is maxing out at roughly 50%. This will remain consistent for the entire ride. A reset of the controller by fully disconnecting the battery seemed to fix the issue for about 5 minutes at a time in the past.. more recently hasn't resolved the problem even temporarily so I could be mistaken and this can be taken with a grain of salt.
Battery and DC current:Battery is in good health, 3 years old, 250 cycles.
52v - 14S4
BMS is 30A
Cells in 14s4 arrangement are capable of 40A continuous.
Solid 30A provided consistently while below 12mph.
I have replaced the main DC current wiring all the way from the
BMS inside the battery chassis through to the last 1-foot of the MP5 wiring harness. Lots of power and torque available below 12mph. Nothing seems to be limiting available current for the controller. The voltage drop is minimal while the problem is happening and is in line with expected vdroop @ 350 watts load.
Just off of fully charged, resting will be ~58.0V and will drop to ~53V under full load 30A. The same battery and charge state above 12mph will only drop to ~55V and 350w load... so doesn't seem like a current limiting issue before the controller.
Throttle + Signal wiring:
Replaced throttle with a new hall sensor based unit.
Tested new throttle independently of the rest of the system and it puts out a throttle signal range of 0.86v to 4.05v without any issues. I wouldn't consider the new throttle as a potential cause as the issue predates the new throttle by about 6 months.
Replaced the throttle wiring (ground and signal) from the MP5 Control Harness' waterproof "throttle and lights" connector all the way to the throttle itself.
Other / MP5 configuration:There are no accessories, horns, lights, displays, PAS sensors, etc.
It's just the battery, CycleAnalyst Shunt ( CA NO THROTTLE, wired directly to MP5), hall-based thumb throttle, and the MP5 controller.
Controller:I've opened it up to inspect and there is no debris, no corrosion.. all clear in the hub. The hall sensor connector is secure and seated nicely. The stator windings are connected securely to the controller and I've made sure the spade connectors aren't loosely fitted. I didn't look very carefully at where the throttle signal comes into the controller at the time.
Any thoughts?
Thanks very much!!
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