So i read recently that thew new HTC EVO 4G LTE (which i just ordered ) is now using a Lithium Polymer battery, rather than the Li-Ion battery in the original Evo 4g (which i currently have.)
My question is, will I be able to use my old car charger and travel charger, that i've been using on my original EVO, on the new Evo with out any problems or risks of damaging the battery? I don't really know a ton about battery technology.
Names of rechargable lithiums
There are nearly a dozen different chemistries of rechargable lithium ion batteries but we will be specifically talking about Lithium Ion and Lithium Ion Polymer as a group.
Lithium Ion cells tend to be either rectangular or cylindrial. They are hard-shelled with a strong casing. They often weigh a little more and come in larger capacity but they are also more sturdy and are hard to puncture. They're often used for laptop batteries and other big packs. These are often called:
LiCo (lithium cobalt, the anode chemistry)
Lithium Ion Polymer cells tend to be thin rectangles in a silvery bag. They are soft-shelled and have an easy to damage casing. They often weigh a little less and come in smaller capacity. You can fit them into smaller devices such as tiny iPods. These are often called:
Lithium Ion Polymer
Despite the structural differences, you should treat them similarly and consider them two versions ('gentle and light' 'tough and strong') of the same kind of battery.
Voltages! 3.6v? 3.7v? 4.1v? 4.2v? 4.35v?
Depending on the design and chemistry of your lithium cell, you may see them sold under different nominal "voltages". For example, almost all lithium polymer batteries are 3.7V or 4.2V batteries. What this means is that the maximum voltage of the cell is 4.2v and that the "nominal" (average) voltage is 3.7V. As the battery is used, the voltage will drop lower and lower until the minimum which is around 3.0V. You should see the number 3.7V written on the battery itself somewhere.
When charging batteries you must make sure that the charger voltage is less than or equal to the battery voltage. For the best battery performance/life you should have them matched.
3.7/4.2V battery and 3.7/4.2V charger: OK
3.7/4.2V battery and 3.6/4.1V charger: OK (but not ideal)
3.6/4.1V battery and 3.6/4.1V charger: OK
3.6/4.1V battery and 3.7/4.2V charger NOT OK!