Hi guys, I am trying to build a system by which an 18v. 10w. solar panel charges a 3.7v 6600maH Li-ion battery pack, this one to be exact: -

http://www.tenergybattery.com/index....d=123&Itemid=1

I have experimented (using my mobile phone) with connecting up a regular car mobile phone charger (converting 18v panel input into ~ 5.5v output ) with some success. However, I am concerned that connecting this directly to my tenergy battery pack will cause problems as I know that li-ion batteries are easy to destroy without the correct protection circuits.

The information with the tenergy battery states that the protection for overcharge/discharge is built in to the pack but the webpage also seems to imply that protection circuits such as

Rechargeable Batteries & Battery Chargers - Protection circuit Module ( PCB ) for 3.7V Li-Polymer Battery (8.5A limit)-PCB1S

and

http://www.tenergybattery.com/index....mart&Itemid=27

are required??? What do you guys think of all of this?? Can I just whack my solar panel output onto the battery terminals via my mobile phone car charger or am I missing something???

Also, I have noticed whilst trying to charge my phone with the solar panel that it works perfectly, but when the power goes off for whatever reason (eg sun going behind a cloud) the phone doesnt start charging again when the sun reappears.. is this some kind of protection built into the mobile phone charger??????????

I am a bit of an electronics noob so I would be most grateful for any help as I am finding very little useful info in google searches and tenergy and the battery websites dont reply to queries...

Thanks in advance