I'm thinking of trying to charge my Lenovo Thinkpad X60s battery with an R-14 Powerfilm flexible solar panel.
The idea is to charge the battery with it in the laptop, but with the laptop turned off. I think having it turned On will most likely not work, for lack of supply power.
I think I have a basic Ohm's law type of problem - I've been told that since the wattage of the solar panel is much less than the draw of the Thinkpad, it won't work. I'm not an electrical engineer, although I did quite well in physics. The only problem is, it's been quite a few years (of disuse.)
Here are the numbers :
=======================
R-14 Powerfilm
The Powerfilm is rated at 15.4V and .9A ( ~14 watts)
Lenovo Thinkpad X60s Laptop
The battery is a lithion 14.4v / ~5200 mAh.
I'm not sure if the charge controller is internal or external to the battery, but it's within the confines of the laptop anyway.
=======================
I measured the current draw of the Thinkpad when plugged in - and when OFF (battery charging only) - at .25A and 115v (= 29watts ).
When On, it's something over 50 watts.
I measured this straight out of the wall, before the inline transformer that converts the 110v to ~20v (?). (I'm not sure what the charging voltage is, but the charger says 20v / 3.5A = 70watts - probably what's need to actually power a running computer)
I had thought that the battery charging would charge at a much lower current, like a trickle current, .1C or so, but this is not necessarily the case with Lithion batteries it seems. See Lithium Ion Battery Charging Basics
It's more like .2 to .7C actually.
One idea, if this is not going to work, is to pull the battery off and charge it outside the laptop, but this looks complicated as there are about 8 or 9 contacts on the battery, and I have no idea what is what. It sounds a little risky anyway.
If anyone could be of help that'd be great.
(I tried posting over at RFCafe, but so far not too much feedback.)
Thanks,
Kent
The idea is to charge the battery with it in the laptop, but with the laptop turned off. I think having it turned On will most likely not work, for lack of supply power.
I think I have a basic Ohm's law type of problem - I've been told that since the wattage of the solar panel is much less than the draw of the Thinkpad, it won't work. I'm not an electrical engineer, although I did quite well in physics. The only problem is, it's been quite a few years (of disuse.)
Here are the numbers :
=======================
R-14 Powerfilm
The Powerfilm is rated at 15.4V and .9A ( ~14 watts)
Lenovo Thinkpad X60s Laptop
The battery is a lithion 14.4v / ~5200 mAh.
I'm not sure if the charge controller is internal or external to the battery, but it's within the confines of the laptop anyway.
=======================
I measured the current draw of the Thinkpad when plugged in - and when OFF (battery charging only) - at .25A and 115v (= 29watts ).
When On, it's something over 50 watts.
I measured this straight out of the wall, before the inline transformer that converts the 110v to ~20v (?). (I'm not sure what the charging voltage is, but the charger says 20v / 3.5A = 70watts - probably what's need to actually power a running computer)
I had thought that the battery charging would charge at a much lower current, like a trickle current, .1C or so, but this is not necessarily the case with Lithion batteries it seems. See Lithium Ion Battery Charging Basics
It's more like .2 to .7C actually.
One idea, if this is not going to work, is to pull the battery off and charge it outside the laptop, but this looks complicated as there are about 8 or 9 contacts on the battery, and I have no idea what is what. It sounds a little risky anyway.
If anyone could be of help that'd be great.
(I tried posting over at RFCafe, but so far not too much feedback.)
Thanks,
Kent
Last edited: