Notebook Battery Chargers?

Nilatir asks: "Here at the University where I work we're checking out Dell notebooks to the students in the library and our main lab. While this is proven to be good for the students I'm having a hard time managing the batteries for the notebooks. By eliminating the floppy drives and using wireless APs to access network shares we were using two Li-Ion batteries in every Latitude and getting almost 8 hours of life a day from them. But, due to some students undying dependence on floppy disks, we were forced to drop down to one battery which will only last half the day at best. We now have an extra battery for each notebook with no way to charge them (even Dell's docking station has no charging bay). Have any slashdotters run into a problem like this and how you all resolve it? Does anyone know of external battery charging station for notebook batteries?" Will laptop makers ever learn that this is one of those accessories that would sell like hotcakes?

Comments

spare laptops

[dnight]

I have the same problem, and we actually try to use one of the laptops that hasn't been checked out yet to top off the batteries. It's a pain in the ass, but at least the Latitudes have the LED battery indicator on the battery, and stop flashing the laptop power light when the tthings are charged.

It's one of the most damned expensive external chargers I've ever seen, though.

Some Laptop Companies Offer These

[JLester]

I know Compaq, HP, and some specialty educational "mobile lab" companies make laptop charging stations. They have a space for the laptop and one extra battery for each. The one I looked at even had a spare power plug so the student can go to the station, plug in the laptop, swap the batteries, and unplug the laptop without shutting down or losing their work. I'm not as familiar with Dell, but at least call their education department and check with them. If they sell mobile labs, it's a good bet that they have something similar.

Jason

EE Department?

[mary_will_grow]

I will assume this college of yours has an electrical engineering department. Ask one of us! We are friendly especially when project ideas are accompanied by a case of beer!

A different approach

[joshuac]

why not an external USB floppy, and keep the dual internal batteries? Check out the floppy drive as a seperate item only for the students who feel they need it. That also buys you the ability to check out drives capable of handling different media beyond what the modular drive sold with the laptop (1.44MB floppy?) could handle.

Re:Hack

[cybermace5]

It's one idea, but anyone who tries it deserves an all-expenses-paid trip to the Darwin Awards winner's circle.

If you try this, you almost certainly WILL lose property, and in the extreme case, life. Batteries aren't so innocent anymore, now that the days of ni-cad batteries are over. The power densities and chemistry are more powerful and more volatile. A Li-ion battery WILL EXPLODE IF MISTREATED. Chargers for these batteries include microcontrollers to precisely monitor and control the battery; in fact this is required by law.

Never, ever mess with the battery. You'll be better off finding a solution that provides the correct DC input to the laptop's power jack...like the power adapter that came with the laptop.

Re:another alternate floppy suggestion

[crow]

On my Latitude C640, you have one battery-only bay, and one that you can swap between battery, floppy, and CD/DVD. There are only two bays, so you have no option for two batteries and an internal floppy.

However, there is a cable that will plug into the docking station port and connect to a drive that you would normally use in the bay. So it can be done, but hanging a drive off of a cable is a pain.

a Google question

[extra88]

It's clear from a Google search "dell battery charger" that they've offered chargers for at least some models of Dell laptops. I gues you'd be helping yourself if you specified which Dell models you had.

Dell Documents - Battery Charger Note this page is from their Asia Pacific site.

Dell Introduces Thinnest, Lightest Latitude Notebook Ever

Li-ion charger ICs commonly available cheap

[xtal]

You can get a battery charger IC cheap cheap cheap from any number of sources now. Most come with a example application that details how to build the charging logic. Do not attempt to charge a li-ion battery any other way, they will explode violently. I've had coin cells go off like small grenades by pulsing them with 1A @ 12V (don't ask).

Steve

Re:Li-ion charger ICs commonly available cheap

[xtal]

The extra terminals are usually control logic. A little investigation can reveal what they are, or you can do what I did: I got a half dozen Compaq notebook batteries for $5/each surplus and smashed up the cases and took out the cells, and made my own packs sans logic (with charger chip). I forget what I was doing with them now though, but with 20 or so li-ion cells you have about the same power as a mid-size lead acid.

Lead acid batteries don't need much in the way of charging intelligence. If they're 12V, the cheapest solution is to use a trickle-charger from an auto store.

The coin cells, heh.. well, I needed to use my meter and back in the day the only one I had was a crummy radio shack piece of junk that took coin cells. I figured if I pulsed some current into 'em, I'd get some measurements. It worked until I got greedy and did it a few times, then it went off with a LARGE bang and almost embedded itself into my arm. Not recommended.