What battery

[MiRaGe]

Hi

I have a b18c6 engine in my car, doesnt have a a radio, just a toad alarm. I have a Odyssey pc680 battery currently and some days it struggles to crank it and others turns it straight away. The battery is in the back with 0 gauge cable going from the back to the fuse box, to the starter also, from the battery neg to the car chassis, have cleaned all the grounds too.

Is it the battery at fault or would it be the length of the cable? starter motor is good.

Did think about getting a new battery but wouldn't know which one to get for the back of the car. I wouldnt get an Odyssey one again I don't think.

 

[Vtex]

Is it struggling to start after a few days sitting or the day after doing a short drive?

Did you run the negative back to the engine bay or ground it in the boot? Check check and recheck your grounds for corrosion and good connection.

How did you prove out the starter motor? The comutator can dirty between the poles can cause high resistance and poor current flow in places and not others.

If you have a multimeter you should check the battery is full (<12.7vdc would be pretty full) before you crank it each day and see what results you get.

If the battery is full cable length is unlikely to affect it if works some days and not other, but you could check it with a meter for a nice low resistance (>0.1ohms), give the cables a wiggle too while checking the resistance in case you have a break. Also check your resistance from the battery negative to the ground strap off the engine, then the starter motor housing to battery and the starter housing to engine ground strap. Again should be very low. Check cable insulation is not worn through somewhere as well.

Unlikely, but try get another battery for a few days if you want to prove that out without diving into the electrics.