For years I have been draining the batteries that power my tools before charging them. It eliminates the “memory” effect that rechargeable batteries are plagued with. Ill use my cordless drill as an example; after driving screws into my deck, the drill gets weak and loses the torque to drive anymore screws. At this point the battery is dead to my purpose, but still has a lot of juice. What I do then is get out the alligator clips, clip them to the battery and look for something on my workbench to play with. Most of the time I use a motor, or a halogen bulb to kill the battery. What I realized is that I could just this power productively, to do something visually stimulating.
Maybe a small fountain with colored water powered by the battery…. Maybe a small fan that blows air past tinsel that looks interesting…. Or how about a strobe light and spinning disc combo! The pattern would change with the amount of charge left. These are my lame ideas. If you had 8-18v to play with, how would you waste it?-- evilpenguin, May 17 2007 laptop battery fire demo http://www.youtube....Pr2CxxvxnlK-s3rtCiA [nuclear hobo, May 18 2007] Seriously overpowered sex toys. Downside: finally running out of charge just as you're hitting your climactic stride. Practice speed swaps.-- elhigh, May 17 2007 With some of the newer cordless tools you are supposed to recharge the battery the instant that you feel a drain in power in order to maintain optimum charge capacity. (Sorry, that's not much help at all is it?)-- 2 fries shy of a happy meal, May 18 2007 ** Danger - Long and tedious educational anno ahead. Reader discretion is advised. **
It depends whether you're using nickel cadmium (NiCd) or nickel metal hydride (NiMH). NiCd are old-school rechargeables that work most efficiently when cycled - that is drained to a low level then fully recharged. Please note I said *drained to a low level* and not completely depleted, because if you were to wring the very last bit of electrical power out of a NiCd the chemical process just might stop completely and your becomes battery landfill (Just kidding - lots of places recycle rechargeables these days). It does not hurt to top up a NiCd battery's charge occasionally. Just don't make it routine or it could become permanently short-changed.
NiMH batteries are newer, at least in the household-use battery world. They have all the down-home goodness of NiCds (they recharge hundreds of times over) without the embarrassment of premature aging (memory effect). As an added bonus, your NiMH battery carries more punch - usually more than double the energy of a NiCd of the comparable size. So you can recharge your NiMHs any time you damn well please.
So, evilpengy, switch to NiMH battery packs for your power tools and stop pissing away electricity, because no matter how entertaining you make it, whatever left-over power you burn off with these assorted frivolous doowhatchamacallit thingys will just have to be put back into the battery when you recharge it. (And if you can't find a NiMH replacement pack then locate your nearest battery rebuild shop. They can convert a NiCd into a NiMH faster than you can say "Flamboyant Battery Killer"!)-- Canuck, May 18 2007 Canuck, respect sir..... thats all I have to say-- evilpenguin, May 18 2007 Lt_Frank - hey, Im very much new to halfbakery. Give me a chance...to....do gooder..?-- evilpenguin, May 18 2007 You could just use the Sony batteries and watch your laptop go up in flames.-- nuclear hobo, May 18 2007 Further to Canuck's fine educational comments - I heard that NiMH batteries will work better if they are kept charged beyond a certain amount. i.e. rather than letting them run all the way down, it's better for them to stay perpetually topped up at over 50% if possible - depleting them as per NiCds can mess them up.-- zen_tom, May 18 2007 //NiMH batteries will work better if they are kept charged beyond a certain amount//
So, presumably, the ideal would be to keep such batteries charged as fully as possible, with only minimal discharge? How about building a small, lightweight battery charger into the power tool itself - I'm thinking that modern switch-mode power supplies could do this, as they are much lighter than old transformer-based ones. Then, just have a lead so that you can plug the on-board battery charger into a nearby mains outlet while you use the tool, thereby keeping the battery topped up at all times. Would also eliminate the need for a seperate charging stand for the battery-packs.-- MaxwellBuchanan, May 18 2007 The memory effect is a voltage reduction which causes some equipment to switch off early. Even NiMH batteries have a small memory effect.
To remove the memory, as previously stated, discharge and charge some full cycles, but don't use something that switches off early like a camera. Also, don't over discharge 'cos this can also damage the battery.
Further to MB's comment: the ultimate is to use a small battery just to bridge those pesky zero volt problems with ac supplies.-- Ling, May 19 2007 Maybe a device that uses electrolysis to convert water to Hydrogen and Oxygen and then later burns them to burn stuff?-- kevinthenerd, Jul 06 2008 there's always the obvious... charge smaller batteries with it.-- FlyingToaster, Jul 06 2008 //...Then, just have a lead so that you can plug the on-board battery charger into a nearby mains outlet while you use the tool...//
corded drill?-- xxobot, Jul 06 2008 random, halfbakery