Battery Gauge for 36 volt Magic Pie

[Dennyb123]

I just finished wiring up my Magic Pie. I'm running 36 volts to it. batteries are fully charged reading 39 volts. When I switch on the pie, the battery gauge on the throttle reads empty. My thumb throttle that came with the pie says 48 volts on it. Is this why the gauge always reads empty, because it's not getting the 48 volts? Any suggestions to fix this problem? By the way, I haven't road tested the bike yet. I'm waiting for new shifters and free wheel to arrive.

Thanks,
Denis

[Hardcore]

it show empty when under a sertain voltage and for 48v that's about 44v or so. you won't get anything else then empty, sorry

[Dennyb123]

If I order a 36 volt thumb throttle (BAC-0100
36V), will this work with Magic Pie, and will it give me the proper battery reading?

[Hardcore]

yes, if you use a 36v battery you should also get a 36v throttle led gauge indicator thingy

[Bikemad]

Denis,
If you can find somewhere to put another 12V battery, you could just run it on 48V instead.

Alan
 

[Dennyb123]

I wish I could. I've all ready purchased the 36 volt charger, fabricated the rack, and found a trunk bag that fits the 3 batteries perfectly. My next build will definately be 48 volts.

[Bikemad]

Denis,
Have a word with Gary Salo (GM Canada) as he might be able to exchange it for you if you're lucky.

Alan
 

[Dennyb123]

I exchanged emails with him last night. He's looking in to it for me.

[rostac]

May I applied for MagicPie Hub Motor these battery  LiFeYPO4 battery  without  Ballancing  and BMS?

[Bikemad]

Hi andto the forum Rostac.

Using LiFePO4 batteries without a BMS is not recommended.

The BMS is there to ensure the cells remain balanced during charging, but more importantly to monitor and prevent individual cells from being discharged too low, as this causes irreversible damaged to the cells, which is far more likely to happen if a BMS is not used.

So to answer your question, LiFePO4 batteries without a BMS can be used with the Magic Pie, but only if you're prepared to risk destroying a perfectly good pack that will probably fail prematurely without a BMS.

Alan
 

 

[rostac]

Are it battery blocked  http://www.auto88.cz/_pdf/ts_2009/TS-LP12V40AH.pdf
12V 40A  (combined 4 x 12V = 48V 40A

[Leslie]

reposted.

Those batteries are too big.

196mm X 161mm, 128mm X4 will get you 800mm X 650mm X 512mm of battery..

Is this going on a bike?

They will fit in a good sized trailer.

[Bikemad]

Those batteries are too big.

196mm X 161mm, 128mm X4 will get you 800mm X 650mm X 512mm of battery..

Leslie, I think you may have slightly miscalculated, you'd actually need 64 of those batteries (4 x 4 x 4) to take up all that space!

Alan
 

[Hardcore]

that's 68v fully charged, the max on mp is what I believe 63v

[rostac]

http://rostac.rajce.idnes.cz/Lehokolo_Velotechnik_Scorpion_fs/#FE245.jpg