I just ordered a 150amp alternator from Eagleelectronics on ebay. Others on here recommended them.

I installed a Webasto heater recently and a couple times I have been left with a dead battery (after I used the heater, started the car, took a short trip and then tried to start the car again). I was going to go with the 120amp version, but the 150amp was only $15 more and I have injection line heaters and I have a 15amp ceramic heater sitting on the shelf that I have considered installing. So I figured I might-as-well do the 150 vs the 120.

I have read through several alternator upgrade threads. I realize that I need to upgrade the wiring from the new alternator to the junction box.

My questions are-
What size wire would be sufficient from the alternator to the junction box for a 150amp alternator? What types of stores carry this wiring?
Do I need to upgrade any other wiring in the system? How about the ground strap or starter wiring?

Thanks!
-Ryan

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2009 ML320 Bluetec
1985 300CD
1981 300TD

Past Mercedes
1979 300TD
1982 300TD
2000 E320 4Matic Wagon
1998 E430
1984 300SD
1980 300SD