Jaypee
Head-Fier
- Joined
- Nov 13, 2009
- Posts
- 77
- Likes
- 0
Hey all, long time since I've posted here! My M3's are still rocking hard and I love them. Since then I took on a different kind of a project.
I'm building a café racer -inspired motorcycle from an -86 Honda XBR. You can read about the build here if youre interested: http://www.thumperclub.com/smf/index.php?topic=4853.msg31972#msg31972
I've run into a corner with the electrics of the bike, with battery choosing and charger cirquit design to be exact. Now I know this has nothing to do with portable audio, but I also know there are a lot of people here with vast knowledge regarding batteries and their characteristics so I'll ask away.
The concept:
The bike has been stripped of most of the useless (to me) electronics and the remaining parts have been replaced with more modern devices with lower power consumption:
- No electric start, only kickstart
- All lighting, except the headlight, have been replaced with LED.
The idea behind this was to minimize battery weigh and dimensions or even eliminate the battery all together. Besides the lights, the bike needs power to produce spark (ignition is CDI type http://en.wikipedia.org/wiki/Capacitor_discharge_ignition).
The problem:
The bike originally had a 12V 12Ah lead-acid battery, mainly because of the high current draw of the starter motor. Since the bike is now kickstart only, my battery rating requirements are minimal - just enough to produce spark and maybe keep a few of those LED's lit before the getting the bike to run - I've estimated it somewhere around 2 - 3Ah's. I initially thought about using a LiFePO4 battery (and still might if I can build a good enough current/voltage limiting cirquit) but they're really picky with the charger input parameters and the alternator is not.
The problem doesn't lie in finding a battery, thats easy, but making the battery last with the alternator.
The alternator is rated 170W/5200rpm. I've been told by people that if I put a 2Ah battery directly in the place of the 12Ah battery, the alternator will boil the battery with excessive current. There is a regulator/rectifier unit after the alternator which should keep the voltage in check, but now I need to make sure the current doesn't get too high.
Conclusion:
I have an alternator designed to charge a 12Ah battery and I wan't to use it with a smaller one. I need a cirquit that can monitor and limit the amount of current (and possibly voltage as well - just to be sure), that flows to the battery.
Hopefully some of you can help me out, thanks!
-Jaypee-
I'm building a café racer -inspired motorcycle from an -86 Honda XBR. You can read about the build here if youre interested: http://www.thumperclub.com/smf/index.php?topic=4853.msg31972#msg31972
I've run into a corner with the electrics of the bike, with battery choosing and charger cirquit design to be exact. Now I know this has nothing to do with portable audio, but I also know there are a lot of people here with vast knowledge regarding batteries and their characteristics so I'll ask away.
The concept:
The bike has been stripped of most of the useless (to me) electronics and the remaining parts have been replaced with more modern devices with lower power consumption:
- No electric start, only kickstart
- All lighting, except the headlight, have been replaced with LED.
The idea behind this was to minimize battery weigh and dimensions or even eliminate the battery all together. Besides the lights, the bike needs power to produce spark (ignition is CDI type http://en.wikipedia.org/wiki/Capacitor_discharge_ignition).
The problem:
The bike originally had a 12V 12Ah lead-acid battery, mainly because of the high current draw of the starter motor. Since the bike is now kickstart only, my battery rating requirements are minimal - just enough to produce spark and maybe keep a few of those LED's lit before the getting the bike to run - I've estimated it somewhere around 2 - 3Ah's. I initially thought about using a LiFePO4 battery (and still might if I can build a good enough current/voltage limiting cirquit) but they're really picky with the charger input parameters and the alternator is not.
The problem doesn't lie in finding a battery, thats easy, but making the battery last with the alternator.
The alternator is rated 170W/5200rpm. I've been told by people that if I put a 2Ah battery directly in the place of the 12Ah battery, the alternator will boil the battery with excessive current. There is a regulator/rectifier unit after the alternator which should keep the voltage in check, but now I need to make sure the current doesn't get too high.
Conclusion:
I have an alternator designed to charge a 12Ah battery and I wan't to use it with a smaller one. I need a cirquit that can monitor and limit the amount of current (and possibly voltage as well - just to be sure), that flows to the battery.
Hopefully some of you can help me out, thanks!
-Jaypee-
