Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  

Go Back   > >

Electronics, Lighting, & Gadgets HRM, GPS, MP3, HID. Whether it's got an acronym or not, here's where you'll find discussions on all sorts of tools, toys and gadgets.

User Tag List

Thread Tools Search this Thread
Old 03-11-10, 02:11 PM   #1
Thread Starter
Join Date: Apr 2004
Location: Cincinnati, OH
Bikes: Too numerous to mention
Posts: 33
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Using AA Batteries to Power Magicshine?

I've read some posts about alternate batteries for the magicshine. They inolved using lithium batteries and a protection circuit.

Could one simply power magicshine with six AA batteries in series? I realize that you would only get approx 2400 mah instead of the 4000 mah that the magicshine battery produces. But there are also some advantages:

- I could take advantage of my advanced AA battery charger (maha 9000)
- Alternate batteries and battery replacement is cheaper (6 x $2.50) vs $40 for magicshine.

Would the indicator light on the back off the light head still work?
Would I need a protection circuit?
mcahill844 is offline   Reply With Quote
Old 03-11-10, 07:02 PM   #2
Seņior Member
ItsJustMe's Avatar
Join Date: Sep 2005
Location: Michigan
Bikes: Windsor Fens, Giant Seek 0 (2014, Alfine 8 + discs)
Posts: 13,737
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 420 Post(s)
I imagine the indicator just goes by voltage. It'd go off at a different time.

Sure, as long as the voltage is in range, I'm sure it'd work fine. I have a friend who is using two MagicShine lightheads running off his 48 volt eBike pack using a couple of buck voltage converters.

The protection circuit on the LiIon is simply in case the wires fray and short out - if you have never seen what a LiIon does when shorted without protection circuits, check YouTube. It would be "exciting" to have that happen on your bike while riding.

NiMH doesn't like getting shorted either, but the effects would generally be limited to getting really damn hot and probably melting the plastic it's in, not exploding, catching fire or jetting around on a rocket of steam.
Work: the 8 hours that separates bike rides.
ItsJustMe is offline   Reply With Quote
Old 03-12-10, 10:21 PM   #3
Senior Member
Join Date: Sep 2007
Location: Seattle
Bikes: Litespeed, O'Brien, Specialized, Fuji
Posts: 271
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
It's probably worthy of an experiment. I can think of some things to maybe consider.
-Yes, you'd get half the runtime.
-6 AA NiMHs is maybe 7.5v. It's not clear to me if the lighthead itself has any minimum voltage shutoff to protect the powerpack from overdischarge (or if it's in the battery pack circuit). If so, it's probably nearly 7v, IIRC. If your NiMH pack has some resistance between each cell, and they start to sag near 1volt each, you might be out of light, or get a stepdown.
-The NiMH pack - I don't know of any good holders with low resistance and easy changeout. The resistance of the springs in common holders is a big problem.
-You could try a 6P2S pack (2 parallel stacks of 6 series) for more current. Bigger and heavier than the LiIon, tho.
-Maybe consider 7 in series, but the max voltage (maybe about 9.8v fresh off the charger) might be too high for the MS head regulator board (maybe designed with 8.4v max in mind).
Litespeedlouie is offline   Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

All times are GMT -6. The time now is 02:57 PM.

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.
  • Ask a Question
    get answers from real people!
Click to start entering your question.