Here's a few tips for keeping batteries working OK:-
Keep terminals clean and connectors tight and greased with vaseline
When changing a battery, undo and spread the clamp apart a bit so it goes down the full length of the terminal post. Tighten the clamp.
Never hammer the clamp onto the post - the casing may crack and always leak acid
Avoid rapid charging - 4 amps will be much less damaging than 10 amps, particularly for a fully discharged battery
Keep batteries charged when the car is not in use
Re-charge a battery that has been left discharged at a very low rate, maybe 1/2 to 1 amp for days - it may recover well enough to do a year or two more in our cars
Keep an eye on the fluid level in hot weather - most are now sealed cells, but some may suffer evaporation.
Top up only with pure water (fridge defrosting ice is fine)
Problems:-
Acid Leaking from posts - very hard to stop this once the seal is damaged
Corrosion of terminal clamps - often caused by acid leaks - clean off, use sodium bicarbonate solution to neutralise, grease; repeat treatment if needed
Battery overheating/boiling - over-charging fault - probably the voltage regulator, but less common with (lower powered) dynamos than alternators
Batteries may freeze and crack in extremely cold weather - fully charged ones are less likely to suffer
Keep + terminal covered by insulation to prevent possible shorting by seat springs (plastic flap may have been fitted originally)
If your early Type 3 has a metal top, be very careful not to touch both terminals or + to frame
Dave.