miami_B wrote: ive had a bit of trouble starting it though, the battery it came with is only a 70amphour one and it appears to be too small for the holding bracket underneath it. what size battery is recommended for this model? it jumps starts easy enough so i figured it must just be because its too small? also when it was running it was at 15.2 on my mates voltmeter.
its 1984 and been stood for quite some time so there's obviously going to be some corrosion/wear and tear issues. Anything else i should look out for? ill get some pics of the pair of them up soon aswell
From your description, you should remember that the electrics also corrode given enough time. So you should also check, preferably replace, the battery earth cable, the battery plus cable going to the starter motor (thick and heavy), and the plus cable between the alternator and battery. All these carry the most current in automotive electrics, and any bad cables or dodgy joints will mean trouble.
Also if it's been standing for a long long time, the battery may be completely dead and if it can't accept a charge the only solution may be to replace it.
I'm running a 55Ah battery on my 360GLT. Yes there's a lot of free space in the holding bracket. But battery technology has also slightly advanced in 25 years. What matters most is actually the cold cranking amps (CCA) rating in the battery. The amp-hour rating tells you how long you can go on cranking the starter if the engine doesn't want to start, or how long you can go on driving when the alternator stops working. The CCA rating tells how much current the battery can deliver in a cold environment. And compared to more modern car, these 300s don't have that much things that consume electricity.
some web page wrote:
Cold Cranking Amps is a rating used in the battery industry to define a battery's ability to start an engine in cold temperatures. The rating is the number of amps a new, fully charged battery can deliver at 0° Fahrenheit for 30 seconds, while maintaining a voltage of at least 7.2 volts, for a 12 volt battery. The higher the CCA rating, the greater the starting power of the battery.
So, conversely, if the starter only takes, say, 100 amps, a higher CCA rating will mean that the voltage will drop less (due to less internal resistance in the battery). Which is a good thing.
Of course, a good battery isn't worth anything if the cables are corroded, green and manky. Also even a good battery will die very soon if the charging system (alternator) isn't working properly or if the charging voltage is too high.
But as it's much more expensive, there's really no reason to do so.