SL-C860 Charger and amperage

[zmike]

I have been using my 5500 chargers on my SL-C860 instead of the somewhat flimsy 100 volt charger that shipped with it. I just realized though that the chargers are 2 amps whereas the 860 charger is 1 amp.
I\'m curious if this has any detrimental effects on battery life?

I just recently had to replace my old 5500 battery since its life seemed to be getting progressively shorter between charges (after over a year of heavy use, so no complaints).

[qx773]

It is my understanding that how much current your Zaurus computer or any computer draws from an AC adapter is a function of the computer\'s activities.  Just because the AC adapter is rated at 2 amps does not mean that 2 amps are constantly pouring into your Zaurus.

I was using the 100 volt AC adapter that came with my SL-C760 until I realized that the battery was not getting a full charge.  The charge LED would go out on the computer soon after plugging in the 100 volt AC adapter.  I then tried the AC adapter from my SL-5500, and then the charge LED would stay on.  When the charge LED finally turned off, the taskbar icon for the battery indicated a full charge.  Clicking on the battery icon showed more detail, with an almost-full charge, just one notch short of full.

[raybert]

You must have a defective charger because mine has not exhibited this problem.  My charging light stays on the entire time it\'s charging and, when it goes out, the battery applet indicates 100% charge.

~ray

[qx773]

Another possibly raised by someone in Japan is that the battery might be dying from being overcharged.  If your battery starts to lose its ability to hold a charge, perhaps it can be revived by using a 110v AC adapter if you have 110 volt outlets.

[raybert]

I just measured the output of my charger and my wall A/C.  A/C is ~120 V (which is nominal in the US, despite the fact that it\'s suppossed to be 110) and the output of the charger is 5.3 V.  That\'s pretty nominal too (the Zaurus wants 5V).  If the voltage was significantly higher (say maybe, 6+ V) I\'d guess that this may be a viable idea.  But I doubt 5.3 V will do any harm.  The charger itself may be at more risk since it\'s rated at 100 V, but it\'s probably designed with enough overhead to handle even 120.

Of course, I\'m not an electronics expert; I only know enough about this stuff to get myself in trouble.   So it would be helpful to hear an opinion from someone with more electronics expertise.

~ray

[qx773]

The EA-72 adapter which came with my SL-C760 outputs at 1.8 volts.  The EA-70 adapter which came with my SL-5500 outputs at 5.2 volts.

[jrsjkd]

i just measured my Ea-70 @5.231V.  My EA72 is measured at 5.163...

Im not going to worry about .068V difference.

Im willing to bet you either got a bad reading or have a bad charger.

[raybert]

The EA-72 adapter which came with my SL-C760 outputs at 1.8 volts.

I suspect this is your problem then: bad charger.  This probably explains why your charging light goes out almost immediately.  There is probably a small surge (normal) when you first plug it in, which makes the Z think it\'s on the charger.  But once the voltage settles down to your measured 1.8V, the Z thinks it is then off the charger because 1.8V is probably below the threshold it uses to judge whether it\'s on the charger or not.

I would chuck it and buy a new 5V charger at Radio Hack or something.

~ray

[Talyinka]

Modern chargers chop up the output delivered from the wall into suitable portions, then integrates these across a capacitor to give a stable output voltage.

As long as nothing gets warm things are normally all right. The amps rating is normally a max rating (these chargers use a constant voltage, not a constant current) but that said, depending on the circuit you charge into, it is a good idea to stick reasonably close to the recommended max current because the circuit may depend on the charger to limit the current flowing into the battery. I haven\'t seen a schematic of a SL-C860 so I don\'t kow which components sit in the battery charger circuit, hence this slightly airy explanation :-)

Mentioning it: does anybody have access to a hardware manual for the C860?