12 volt car battery

[balterzar]

Are all 12volt batteries the same (don't mean size or connections) the rating

[Electrochem]

No. They vary quite a bit.

Batteries for diesel engines tend to be heavier duty, because of the higher compression ratio.

[BillyNoMates]

Absolutely not. Different cars have different electrical demands so some batteries are more beefy than others.

The rating is usually given in Ah or Ampere Hours which gives an indication of how long the battery would take to discharge when passing 1A.

There is also a cold cranking value which gives an indication of the short-term capacity when starting.

Generally diesels have higher capacity batteries fitted and larger cars with all the accessories etc.

Because of the differences, different capacity charging systems are required too.

[noseyno]

What battery for a 20 hp outboard. THANKS