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imported post
y'all:
I've often thought of building a battery pack for my old bike using left-over NiCads, Lithium-ion, or Nickel hydride batteries but I've learned it could be a big mistake.
Normallead-acid batteries have such a high internal resistance that they can only pass so much current even under a dead short. This self regulation is a safety feature in that a dead short may cause some sparks or a blown fuse, but that's aboutall.Usual automotive and motorcyclebatteries (Gell-Cells, Lead-Acid, Sealed Lead-Acid) are used because they are easy to charge using simple circuitry, they provide voltage regulation without added devices, they're safe and they don't cost much.
On the other hand, super batteries (NiCad, Lithium-ion, or Nickel metal hydride) batteries can pass hundreds of amps in a split second and an accidental momentary short can cause a severe meltdown or even an explosion. Uncontrolled charging current can do the same. Manufactured super-battery packs usually have an on-board ESC or regulating device to limit the current flow along with a sophisticated charging circuitto make sure they operatesafely.
I've oftentaken apart a laptop battery pack and wondered what all those extra circuit boards are for....well, that's what they're for.
I've also discoveredbuilding a home-made battery pack using super-batteries, including the control circuit for current limiting and charging cycles is well beyond my capabilities as an experienced electronics builder, however there are some commercial items from china I saw recently that sound promising as well assome from this supplier:
http://www.tekbattery.com/battery_prices.html
You'll note the price even for a small battery pack is around $1000 CAN. probably more than my bike is worth!
Also, soon to be available:
http://thekneeslider.com/archives/2007/02/02/lithium-ion-polymer-motorcycle-batteries/
I guess I'll just stick to my normal Yuasa 6N6-3B....about $20 every 4 years, rather than make my bike a bomb.
I've also learned to check my battery fluid level every week in the summer and make sure the fluid is well over the plates, replacing it with distilled water. If you do that, your cheapstopper-top batterywill last as long as a sealed unit.
hmmmm....that's about 2 cents.
Sparkle