Battery Charging Question - High Voltage?

Hi,

The short version: Would a charger rated for 5.7V 800 mAh damage a Li-ion battery designed to be charged at 5V 1A?

The long version:

Not strictly a flashlight question but it does apply to Lithium batteries in general so I'll take a chance. Apologies in advance for an OT question....

I've just changed from a Nokia mobile phone to an HTC Hero and I've seen adapters for changing the Nokia chargers to the HTC compatible Mini USB connector.

The HTC manual states that the battery is a Li ion 5V 1350 mAh and should be charged at 5V, maximum 1A (which is the stated output of the supplied charger).

I have a bunch of old Nokia chargers breaking down to 2 types:

The newer small pin type charges 5V 350 mAh. This looks fine for charging the HTC in an emergency (if a little slow).

The older type with a large pin charges at 5.7V 800mAh. Here's my concern, is 5.7V going to do any harm?

Any advice would be much appreciated.

Cheers!

Dave

Can you double check your units? Current is not measured in mAh.

Sorry! I put the "h" on the current values by mistake. Doh!

Cheers

Dave

Personally I would not play such "mix and match" games. The power adapter for a phone is often matched to the phone. If the phone has a USB charging cable you can plug the phone into a genuine USB power hub, but otherwise you should not plug it into other power sources.

in your phone there is a regulator circuit which step down the voltage supply to battery, it should be safe to use such adapter.