GoldenMotor.com Forum
General Category => Magic Pie & Smart Pie Discussions => Topic started by: Marlz on September 12, 2016, 04:36:32 AM
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So I have 12 MP4's, 6 I bought a few months ago and 6 I just got.
The ones that I bought before, when you charge them the throttle lights do not come on.
The ones that I just got, when you charge them the throttle lights DO come on.
Anyone know why that might be?
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It definitely wouldn't be caused by any differences in the MP4s, so it must be the batteries that are different (or the way they are wired up).
Some batteries actually state that the power switch must be in the "ON" position in order for the battery to charge, so unless you physically disconnect the battery supply wire from the controller, it will obviously be supplied with battery voltage, and this may be why the throttle LEDs are lighting up while on charge.
If the charger supply has been wired to the output side of the power switch instead of the battery side (either deliberately or accidentally) this would also send the charging current/voltage to the controller as well as (or instead of) the battery.
This may have been done intentionally by the battery manufacturer so that any regen current from the motor can still pass through the charging circuit of the battery's BMS while the battery power switch is turned off, although a suitable diode soldered across the switch connections would have been a much better solution. :-\
It is difficult to understand why your batteries/chargers might be wired like this without knowing exactly how they are wired internally and how the BMS is designed to operate.
- Exactly what batteries are you using?
- Do they have separate cables for the power outlet and charging input?
I would also check that the batteries are actually being charged while the power switch is in the "OFF" position by measuring the battery voltage both before and after a full charge. ;)
Alan
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Hello Alan, and thank you for your reply.
I charged the batteries overnight and they did in fact get charged.
As for what kind of batteries I'm using, 48V 12Ah Panasonic cells (can't recall the exact type) in a dolphin case, built in China.
This case slides into a rack which has a red and a black wire coming out of it which is the power out. The charge input is a socket near the top of the case.
Thanks again.
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I have got a battery of that type too, and I think its a flaw powering the bike when charging, what if someone accidentally touch the throttle while charging, anyway I disconnect the output just in case, I surgest you consider that too ;-)
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Perhaps it is simply an assembly error and the charger lead has accidentally been soldered onto the wrong switch connection, as I can't see why it should be necessary to have a live output during charging.
It would be nice to know exactly why they have been wired that way.
(http://www.arhservices.co.uk/GoldenMotor/emoticons/thinking.GIF)
Alan
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I am sending one of the batteries to someone who knows more about these things than I. I will report back with his findings.