Battery Problem - Hard to start

[ElementalFiend]

I've got a battery problem I'm trying to sort out.

1991 240sx hatch

Car has been fine for the last 6 months I've had it. One day it was hard to start. This got progressively worse each day after until it was impossible to start. I cleaned the terminals and that worked for a while. It got to the point where I had to clean the terminals every time I wanted to start the car due to corrosion building up so quickly. So I've replaced both terminals and the car started perfectly for a while. Now the problem is happening again, except there is little corrosion on the new terminals, so I no longer believe that was the cause.

Any idea where I should start looking for the source of this problem? It is a pain to clean the terminals every time I need to go somehwere.

Other info:-The battery checks out fine and has been fully charged. The car starts great once I have a solid connection to the battery.-I only replaced the terminals, not the cable (I don't know how).-I'm a newb.

Thanks for any help.

[r3v_v3ng3]

you can check for voltage drop on yours starter wire (+ to the battery). if its excessive, replace the starter wire to the positive terminal of the battery

[Vegascorbin]

You probably have corrosion in the cable. If you can replace the terminals you can replace the cables.

[ElementalFiend]

you can check for voltage drop on yours starter wire (+ to the battery). if its excessive, replace the starter wire to the positive terminal of the battery

Do I use a voltimeter for this? What is the standard voltage and what would be considered excessive? Thanks.

[Vegascorbin]

Place the black lead fron the meter directly on the negitive terminal of the battery. Place the red lead from the meter directly on the positive terminal of the battery.

Remember this reading.

Car off this reading should be 12.5V or higher. For now the voltage does not matter as much.

Leave the black lead in place and connect the red lead to the high current terminal on the starter (where the big wire connects).

This voltage should be the same as the above reading. If may be off a little (0.2 volts) due to the resistance in the wire. If it is off much more than 0.2 volts then replace the cable. (12.5 at battery, 12.3 at starter OK. 12.5 at battery, 11.9 at starter BAD)

This test is done with the engine off. IT IS NOT ALL INCLUSIVE. There is other testing that can be done both with the engine off and on, but this should give you a quick indication of the condition of your cables.