The electronics for rechargeable flashlights are usually in the charger. Flashlight itself is typically just battery+switch+bulb. Rechargeable batteries do have a LIMITED life. Sometimes you can revive old batteries with special charging methods, but the batteries are still near/at the end of their useful life.

Your best options are to replace battery or just buy a new flashlight.

Key word "Electrician" not "Electronic Engineer". What do they know about battery technology. If it is Ni Cads replace them with same a/hr. This is normal they can last depending on memory effect 6-12 months. They like to leak also.

This is good advice form Dave,

I had a Yaesu 2m/70cm Handheld that needed a new battery pack at a cost of £42.00, so I took apart the dead one and replaced the 6 AAA NiCd's for less than a tenner, plus they had a higher capacity than the originals so lasted longer. Although it wasn't designed to be dismantled, with careful precision, dexterity and a spot of glue to finish off you couldn't tell that it had been repaired and I had a better spec battery pack than if I'd coughed up more than 4 times the cost for a replacement.

Type of batteries & ratings ???

If you have had it for several years, there is a good chance it is an incandescent lamp type. By now the LED type torches have gotten so good and so cheap that it is probably better to just buy an entirely new one.

Last Christmas I bought a pair from Costco. They have a super capacitor which is charged by a solar cell, and also have a couple of button cells for when the capacitor is used up. When I tried them, I liked them so much I went back and bought a bunch more for Christmas gifts. After nearly a year of regular use, I've never needed the batteries. The only negative I've heard is from one friend who left one in the hot sun on the dashboard: it how has an angled front end, and is probably no longer waterproof, but it still works! I keep one in the door pocket of my car, and have had no problem.

you can see them at http://www.hybridlight.com/.

I did NOT check to see if they have any distributors in Israel...