Motor help - PLEASE!

[coombro]

I remember going over DC voltage last semester in class at school. I went and looked in my text book and 12.67 V at 68 dergees F is considered charged. If the dempature drops to 20 degrees F 12.0 V is considered dead. At 68 degrees F a fully charged battery will normally read 13.6 V + or - .2 which = 13.4-13.8V. Just 1 drop in volts can drastically reduce the performance of a 12v battery.

Ah yet you need to figure in the 10% voltage rule. Voltage fluctuation is figured at the 10% rule for operation being ac or dc. 12 volts is 12 volts. His sounds like an amp problem. You can have 12 or 13 volts all day yet if you don't have the amperage to back it up your dead in the water.

[Embrey]

Ah yet you need to figure in the 10% voltage rule. Voltage fluctuation is figured at the 10% rule for operation being ac or dc. 12 volts is 12 volts. His sounds like an amp problem. You can have 12 or 13 volts all day yet if you don't have the amperage to back it up your dead in the water.

yup...mine has read anywhere from 12.3-12.7 for years and still cranks like a champion

[basshuntin]

You can not tell if a battery is bad by reading the voltage when the battery is not under a load. If you can, check the voltage while the motor is cranking. My bet is your battery is bad and your voltage is dropping way down when you put it under a load.

[coombro]

You can not tell if a battery is bad by reading the voltage when the battery is not under a load. If you can, check the voltage while the motor is cranking. My bet is your battery is bad and your voltage is dropping way down when you put it under a load.

Agree 100% like some one said take it to Auto Zone they have a special tester there that will pull it down while testing. . Like that someone said a dead cell will still read 12 volts and run some items, but when it takes a load such as turning over a motor it can't hang.

[floatman]

I have a 200 Merc, the starter was going bad, it acted like a dead battery, if the battery is food might be the starter.

Gary

[floatman]

not food, GOOD........LOL