New Battery??? I have several TI-15 calculators that do not work at all. Can I replace the batttery? They are also solar powered so I'm not sure if this is the solution, but I hate to have to toss them just b/c they won't turn on. Thanks

Certainly looks like it friend !
There you go !
https://www.ifixit.com/Guide/TI-36X+Pro+Battery+Replacement/25507

You don't. The 30X IIs runs on both solar power and a 2025 lithium battery. If you need to replace the 2025 battery, see this.

This is a battery-powered calculator. There is no solar panel. It uses two GPA76 batteries.

Here's the official word from TI on replacing the 30XA's batteries:
http://epsstore.ti.com/OA_HTML/csksxvm.jsp?nSetId=103095

You can't recharge it. It is a solar calculator with watches battery. You need to change the battery.

The BA-35 takes two A-76 batteries.

The BA-35 Solar doesn't take batteries, being powered exclusively by the photocell.

It is battery powered. You simply need to replace the battery. This website may help you.

http://www.calculatorsource.com/ti-30xa.html

Hello,
If they are solar powered and if the power down button is not functionning I would not worry about them. Usually battery powered calculators have an automatic power down feature, and sometimes solar powered machines as well. The only free thing we get is the sun's energy. Maybe not the only one (oxygen).
Hope it helps.

Hi,

The only solution which can be tried is replacing the battery.

Goodluck.