GoldenMotor.com Forum

General Category => Magic Pie & Smart Pie Discussions => Topic started by: Dennyb123 on March 17, 2010, 03:08:37 PM

Title: Battery Gauge for 36 volt Magic Pie
Post by: Dennyb123 on March 17, 2010, 03:08:37 PM
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
Title: Re: Battery Gauge for 36 volt Magic Pie
Post by: Hardcore on March 17, 2010, 03:38:43 PM
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 :P
Title: Re: Battery Gauge for 36 volt Magic Pie
Post by: Dennyb123 on March 17, 2010, 03:51:43 PM
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?
Title: Re: Battery Gauge for 36 volt Magic Pie
Post by: Hardcore on March 17, 2010, 08:51:46 PM
yes, if you use a 36v battery you should also get a 36v throttle led gauge indicator thingy :D
Title: Re: Battery Gauge for 36 volt Magic Pie
Post by: Bikemad on March 18, 2010, 01:03:08 PM
Denis,
If you can find somewhere to put another 12V battery, you could just run it on 48V instead. (http://www.arhservices.co.uk/GoldenMotor/emoticons/everyday_think_230608.GIF)

Alan
 
Title: Re: Battery Gauge for 36 volt Magic Pie
Post by: Dennyb123 on March 18, 2010, 01:57:39 PM
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.
Title: Re: Battery Gauge for 36 volt Magic Pie
Post by: Bikemad on March 18, 2010, 02:48:05 PM
Denis,
Have a word with Gary Salo (GM Canada) (http://goldenmotor.com/SMF/index.php?action=profile;u=8525) as he might be able to exchange it for you if you're lucky. (http://www.arhservices.co.uk/GoldenMotor/emoticons/fingerscrossed.GIF)

Alan
 
Title: Re: Battery Gauge for 36 volt Magic Pie
Post by: Dennyb123 on March 18, 2010, 02:58:12 PM
I exchanged emails with him last night. He's looking in to it for me.
Title: Re: Battery Gauge for 36 volt Magic Pie
Post by: rostac on May 01, 2010, 11:12:41 AM
May I applied for MagicPie Hub Motor these battery  LiFeYPO4 battery  without  Ballancing  and BMS?
Title: Re: Using LiFePO4 batteries without a [acronym=Battery Management System][color=teal]BMS[/color][/acronym]
Post by: Bikemad on May 01, 2010, 11:37:13 AM
Hi and(https://i.imgur.com/evDSMvT.png)to 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
 

 
Title: Re: Battery Gauge for 36 volt Magic Pie
Post by: rostac on May 01, 2010, 01:39:12 PM
Are it battery blocked  http://www.auto88.cz/_pdf/ts_2009/TS-LP12V40AH.pdf
12V 40A  (combined 4 x 12V = 48V 40A
Title: Re: Battery Gauge for 36 volt Magic Pie
Post by: Leslie on May 01, 2010, 06:54:39 PM
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.
Title: Re: Battery Gauge for 36 volt Magic Pie
Post by: Bikemad on May 01, 2010, 07:16:32 PM
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
 

Title: Re: Battery Gauge for 36 volt Magic Pie
Post by: Hardcore on May 01, 2010, 08:07:32 PM
that's 68v fully charged, the max on mp is what I believe 63v
Title: Re: Battery Gauge for 36 volt Magic Pie
Post by: rostac on May 01, 2010, 09:39:52 PM
http://rostac.rajce.idnes.cz/Lehokolo_Velotechnik_Scorpion_fs/#FE245.jpg
Title: Re: Battery Gauge for 36 volt Magic Pie
Post by: Leslie on May 01, 2010, 11:37:51 PM
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




LOL yeah. 8)  I thought something was a big bit out when I posted that.  I even reposted it ???.  Doh. 

I think I had a dream of this massive pack on my bike not very long after I posted this.
Title: Re: Battery Gauge for 36 volt Magic Pie
Post by: Leslie on May 02, 2010, 12:47:06 AM
Ok Ill work it out.

To get an idea of what the whole pack will look like stacked into as close to square.

One way to look at this.

196L x (161H + 161H) x (128W + 128W)

Or rounded off for a battery box, 20cm X 33cm X 26cm


Have I got it right this time.
 
Actually that's quite acceptable.  Over doubles my capacity for the same weight at 24kg.