Running a 18volt li-lion battery

[novel8]

I have this edger that uses this battery and the manual says after using it a few times, let it run till your battery is dead and then immediately recharge it and it would finally be at its full capacity. How does one run a battery like that, not looking like a jerk standing there with the on button depressed and holding the running handle? One can be standing there for at least about 10 minutes or more. Of course if you have a large area to do, than that may not be a problem...but i use up close to 15 minutes till my lawn area is done. The manual says it last about 30 minutes. on a full charge. Sorry, not too saavy on batteries.

[Jeff The Drunk]

Just use it until it dies. LIon batteries are not too choosy. I have a pair for my Hitachi drill and just used the drill until each one died. Once a lIon batter dies it dies fast so you won't be trimming weeds at 30 rpm forever.

[DA]

They must have forgotten to edit the manual after switching to a new type of battery. Unlike NiMH, Li-ion batteries don't have memory effect so no need to fully discharge them. In fact, running them unnecessarily may shorten their lifespan - they are susceptible to overheating, so why would you heat the battery by discharging it for no good reason?

------------------------------------- /\_/\ ((@v@)) NIGHT ():::() OWL VV-VV

[ransley]

Does it actualy say run dead, or run down. Be safe dont run it dead, from the little ive read running it dead may permanently harm itm possibly reversing a cells polarity. There are a few sites you can google to learn battery facts

[ransley]

For Nicad its technicaly dead at about 1.2v a cell or just when the tool slows, everything I use with LiIon shuts off at its low set voltage to not harm the pack. Tool manufacturers dont put in low voltage cutoffs on any tools ive seen. They make their high profit $ on replacement packs they hope to sell you. Do other research before following what may be a chinese translation that cold ruin your pack before youve used it, dead may have been meat to say Run Down, and that to me means just when the motor slows down. I have 18 yr old Nicads from not following manufacturer instructions.

[krw]

1.1V/cell or even 1.0V per cell is the normal threshold. The nominal voltage is just over 1.2V. There is a lot of energy below 1.2V and not much below 1.1V. The real danger here is reversing (reverse charging) a weak cell. If you can guarantee that no cell will have less than 0V across it (+ to -) you can run NiCds right down to zero. In a multi-cell battery this isn't feasible, so the 1.0V or 1.1V per cell numbers. What you say here is true, except that the battery LiIon pack is specified by, if not made by the tool manufacturer. They choose to put the smarts in the battery instead of the tool because it's easier (only one battery to keep track of). If they were out to sell batteries they could just as easily sabotage the battery pack as the tool. LiIon needs this protection because of the dangers of fire and lawyers.

Good advice.

[ransley]

So all LiIon packs have a circuit to protect them? If so thats good. I dont think manufacturers really care if you hurt a pack, the only way I learned of a batteries properties and what harms them is through RC racing and reading technical data supplied from battery charger manufacturers that push cells for maximum power, and articles about battery care from RC racers. Heat, constant cycling, and running a Nicad dead are a few things none of my battery power tool manufacturers include as tips to get maximum life from a pack. I think they know the sooner you ruin it, the sooner they sell you a new pack at full price, so many kits you almost get the tool free, but battery packs are expensive. I take the easy route on batteries, I dont abuse them, and have had long life with them.

[krw]

I've never seen one that didn't (sold to an end-user). Some are more sophisticated than others, but LiIon pretty much requires such coddling. Even with it, I'm sure you've seen the news reports of laptops catching fire or otherwise burning people. Packing power densely always has its problems but LiIon has been particularly difficult to tame.

Well, once the warranty has expired, they don't care. ;-) I tend to buy several tools from the same manufacturer so get the extra batteries "free", for exactly the reason you state above; replacements are expensive. I've also had them (NiCds) rebuilt successfully.

I found Bosch 12V LiIon batteries on sale at the BORG a while back for $15 (I think they got rid of the Bosch rechargeable line and were clearing inventory). I bought all they had (four).

Yes, you're smart to not push them to the limit. Another thing that will kill them is leaving them in the sun on a hot day.