YOU HAVE TO TURN IT ON
Actually, I learned this past week that if it is a gel type battery, you can get a false positive on the battery, so it looks like it is fully charged but actually is not. You can take the battery to your dealer to see if he can charge it or you need a new one.
My 2005 Honda Forman rancher ATV dies unable to start or shift back to neutral when checking battery still says it is fully charged. Could it be a regulator problem?
Our original battery had to be replaced about 4 months ago (we have a 2005 500). The battery showed it was fully charged --- but it wasn't. This was the original battery that came in the car. You might take the battery out and take it and have it professionally checked at a parts store. We thought something else was wrong with the car since it wouldn't turn over, but it turned out to just be the battery.
To charge the battery in a 2005 Cadillac, first ensure the vehicle is off and locate the battery, which is typically found in the trunk or under the hood, depending on the model. Connect the positive (red) jumper cable to the positive terminal of the battery and the other end to a charged battery or a jump starter. Then, connect the negative (black) jumper cable to the negative terminal of the charged battery and attach the other end to a grounded metal surface on the Cadillac. Start the charging vehicle or jump starter, and let it charge for a while before attempting to start the Cadillac.
The first thing I would check on, would be the battery not holding charge(bad battery), The battery terminal should be tight and VERY clean, Alternator not putting out enough juice to keep the battery charged. Or the starter is weak and looking for a replacement..
Bad alternator- not charging battery enough to keep vehicle running check with a volt meter A fully charged battery should read approx. 12.8 volts without engine running With engine running should read approx. 13.8-14.2 volts
A fully charged battery is designed to maintain the parasytic load on an idle vehicle for 21 days. After that period (in most cases) the battery will have been drained and will require either charging or replacing.
You can pull out the metal key that won't work in the trunk and then jump start the car from the battery.
It would depend on the condition of the battery and if the battery charger has a jump start mode.
The parasitic load on this vehicle will discharge a FULLY CHARGED battery in 21 days. What is the condition of your battery and the climate to which it is exposed? You can check to see if the load on this vehicle is excessive. Parasitic (Sp.?) should be 0.07 amps. If over this check as suggested by next answer. Something is drawing power. Possibilities are a under-hood light, courtesy light, glove box light, etc. Another possibility is that the battery needs replacing. vehicle is 2005, is battery the original? sounds like the battery needs replacing a battery that sits idle does not have much of a life span
Check the new battery, check connection cables (the most possible reason but not necessary), check your antitheft system, some of them will not allow start after the battery power outgage.
You, in all probabilty have either bad battery connections, a bad battery or the start solenoid. I would say the connections are the problem.
If you look close you will see that there is a tube to direct air to the battey box. This provides a cooling effect while driving and the battery is being charged.