Hi fez,
Well, they have analog ones too. I am not sure what kind of current you are looking for here though. Is 100 amps enough?
I am also not sure how you want to handle the huge current difference between normal charging and starting. When starting the current can go very high so you either need a bypass switch (not as good) or a means to limit the input to the actual meter which is usually a high sensitivity meter. For example, if you were to use a 500 amp meter movement and starting was 400 amps, that would be up near the top end of the meter travel. While charging however, the current could be as low as 4 amps, so that means the reading will be almost lost on the other end of the meter face which will be harder to tell what it actually is.
The old way was to use two diodes back to back across the meter movement or before some set point resistors. That would limit the max signal that the meter itself would ever see even in the event of a large over range signal. For this though i am not sure if you want ot be able to read that 400 amps too or not, and just go with reading the charge current which might range 0 to 60 amps.
If you want to only read the starting current then a high amp meter would do.
If you want to only read the charging current then a lower amp meter would do with a means to protect it from over range signals.
If you want both, then you would probably need a variable scale where below a certain value (like 100 amps) it switches to higher sensitivity.
In the modern age almost anything is possible. For example, an op amp that reads the signal and provides over range protection to the meter movement, with possibly a comparator to automatically switch ranges.
Then there is also the most modern approach which would be a microcontroller. That would provide fast readings too, analog or digital or both.
I was in favor of an analog meter for my automobile voltage also. It's a simple 0 to 15vdc meter cost about $10 USD new. It has fast response that can catch dips when starting, which is important in order to determine battery health. I was going to build a much more sophisticated measuring system that even included a lower frequency scope type display, but realized i can see a lot of the behavior with the simple analog meter. The scope would display the battery voltage while starting over the first few seconds or so on a graphical output display.
So maybe you can indicate how far you are willing to go with this, and exactly what range of currents you would really like to measure.