Battery temperature is an important charge parameter.
Fortunately batteries have great deal of temperature inertia and as they are usually stored below the waterline the temperature fluctuations are not great.
High current charge sources can heat up batteries. I have never sailed on a boat that has enough charge capacity for this to be a significant issue, but it will be interesting to see if this is the case my new boat
Nevertheless, for most boats, where the charge sources are insufficient to cause significant battery heat, simply manually modifying the battery set points to cope with different seasons, or locations, is generally close enough, but take the trouble to make the changes.
To charge the batteries as quickly as possible the battery voltage set points make a big difference. If you want to adjust the battery set points close to the limits battery temperature compensation is important.
Alternator temperature is very different. This has nothing to do with health
of the batteries but the the health
of the alternator. It is not practical to manually control the alternator temperature. The alternator may be 60įC or more above the air temperature.
So the options are to install:
A large frame modest output alternator that will never overheat
A small frame very low output alternator that will never overheat
A large frame high output alternator with alternator temperature compensation
A small frame modest output alternator with alternator temperature compensation.
All of the above can work
reliably, providing you are aware of the limitations and compromises.