How to check the battery power???

Question

I have an '86 Cadillac that I did not start for almost 12 months. I charged the battery and tried to get it to start. It would turn-over but would not start.

My thoughts: no spark or not enough gas.

So...I bought a can of starter fluid (spray) to try it out.

A few days later, I hooked-up the charger again and let it get a good charge overnight. Then I tried to start it again the following morning.

This time??? Lights work, radio works, electric door locks work...but the engine will not turn over at all. Hmmm...?!?

I am using a 20-year old charger borrowed from a friend. It is the old rectangle-box type in use for decades. I am not sure how to read the tiny meter-thing on it. I am not even sure if it is accurate.

QUESTION: How can I check the battery (while still on the car) to see how much charge it has?

If the battery is charges but it won't turn-over now at all, could I assume that something has "locked-up?" Starter? Solenoid? What?

Thanks for suggestions.

D*

"Anyway, devout religionists are frequently attracted to and bound to their piety largely because it presumably offers them holier-than-thouness and oneupmanship over non-religionists."

--Dr. Albert Ellis

Lon Stowell · Accepted Answer

Approximately 8/8/03 19:33, Don uttered for posterity:

You may want to remove the battery connections, clean them, then put back.

Cheap voltmeter. Remove the charger, don't turn anything on, and measure right across the battery. 13-14 volts or more is probably charged reasonably well. Leave the meter attached and turn on the lights, shouldn't drop much at all. If it does, may have an internal open.

The battery may not be charged, but most common issue is dirty cabling.

Al Bundy · Answer

Voltage of 13-14 is much too high of a reading while the engine is not running and nothing is turned on. It should be about 12.6V. It could be as much as 13V with a huge 'top charge' that would burn off immediately when a load is applied. A no load check is interesting, but not very helpful. Turn the lights on for 30 seconds and be sure the voltage doesn't drop below about

12.3. The main problem the poster has is starting, so concentrate on that. Keep the meter on the battery while someone cranks the engine over. If the reading drops under 10 volts and the engine is not cranking then the battery could be bad or the starter could be drawing too much current. The positive wire would get quite hot in this case. If the battery reading stays at 12+ and no cranking is taking place, you probably have a bad connection, bad solonoid, or bad starter. You could try beating on the starter carefully with a rubber mallet or wood to see if that gets a start out of it. That would send me towards a rebuilt starter. I paid $38 for a rebuilt GM starter with solonoid last year.

How to check the battery power???

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