NW-HD5 Batteries - Cheap alternatives

[KiNeL]

I discovered something interesting about batteries today.

The BST 36 battery for the Sony Ericsson J300i phone is physically identical in every respect to the LIP880 in the HD5, the only obvious difference being that HD5 is Lithium Ion whereas the J300i is Lithium Polymer.

Having done a bit of research it appears that the difference between Lithium Ion and Lithium Polymer is one of physical construction not chemistry and they should therefore be directly interchangeable but I haven't tried it because:

A. I already have a 2nd LIP880 and
B. They are 49.99 Euros (I'm in Germany at the moment Oktoberfesting!).

The REALLY interesting thing though is that BST 36 batteries and chargers are available for peanuts on Ebay, albeit from Hong Kong, and I'm seriously thinking of buying one for the charger if not the battery.

Just type BST 36 into Ebay

[drmoze]

Looks like it has about 10% less capacity than stock. But still a great deal: charger and battery for about $12....

[vonjeff]

I believed that you can't use BST36 in HD5, although the size seems similiar, but the polarity of BST36 is reversed (+/-). Beware, it may damage your precious HD5.

[KiNeL]

Originally Posted by vonjeff

I believed that you can't use BST36 in HD5, although the size seems similiar, but the polarity of BST36 is reversed (+/-). Beware, it may damage your precious HD5.

Tnks for the tip, hard to believe but I'll check it out.

[mrtbag]

Also worth noting:

The BST36 I think is 3.6v 780mA

The Lip8800 is 3.7v 880mA

[drmoze]

Can someone check the polarity on these batteries? This would be a great spare. The slightly lower capacity won't harm the player--still plenty of juice for a spare.

[danwalton]

so is there any way to test this, cuz if it works then its a fantastic find!

[KiNeL]

I'm not in a position to check myself at the moment but I do see that + & - are marked on the LIP880 so maybe they are marked on the BST 36 also, I don't recall when I was looking.

Maybe someone can pop into a phone shop and have a look.

[vonjeff]

Ok, I've uploaded the BST36 image.
Sorry that I can't upload the LIP880 photo, but you can compare with your own.
The position of opening for cathode / anode is different and the polarity is reversed.

[KiNeL]

Seems to be so unfortunately

http://i.expansys.com/i/l/l124543.jpg

http://www.stoneaudio.co.uk/resource...ip880thumb.gif

Bummer

[drmoze]

Any chance another cell phone battery would have proper polarity? Any way to check on this?