biker349

hi, i have a 2004 cl600 it uses a water cooled 180 amp alternator. the 2000-2002 cl600 uses the same alternator, but it is only rated at 150 amps and is half the cost of the 180 amp alternator. question is will using the 150 amp alternator cause any problem in my 2004 cl600?
thanks for your input.

Welwynnick

Doesn't the early alternator have totally different mounting? The water cooled alternator has a water port in the mounting itself, to take the water directly from the block.

Nick

Exotic-metal55

I would stick with the 180 amp, these cars use a ton of juice and you may not be worth having low voltage issues.

biker349

as far as i can tell this is the same exact alternator, water cooled, but is rated at 150 amps instead of mine at 180 amps.

biker349

i may be ignorant so please help. i thought the main function of the alternator was to keep the battery charged and all systems ran off the battery. am i wrong. once my alternator was bad and i charged the battery fully and drove 30 miles to a repair shop with no issues. of course i didn't run the a/c, or lights. so does the amperage of the alternator effect the electrical systems and cause low voltage issues if the battery is charged?
thanks

Welwynnick

The reason for the V12TT having such a huge alternator is not to charge the battery very quickly (the battery can't accept such a high charging current) - its to run all the hungry electrics on the Maybach while the engine is running.

If the 150 amp alternator is water-cooled and is form, fit and function interchangeable, I would say interchange it!

People sometimes get a bit obsessive about using exactly the right parts and consumables. My "proper" battery went flat when I left the lights on at work, but I still got a jump start from a MINI! That has a tiny battery, but it started fine. I bought a used but good BMW 530D battery, and have zero issues. I wouldn't cut corners with fluids and filters, but I happily use commercial standard ABC hoses and Korean tyres. Some details aren't worth worrying about too much.

The main thing with electrics is try to keep the battery between 12.4V and 14.4V at all times to maintain the chemistry and avoid damage, and never let it go below 12.0V. Fully charged is 12.6 to 12.7V, depending on temperature, and with the engine running, the charging voltage wil be 13.2V to 14.4V. It doesn't take a huge charging current to achieve 14.4V - certainly much less than 150 amps! Depending on the capacity and condition of the battery, it will be more like a tenth of that.

So for our cars, 180 amps is a bit overkill for the sake of standardization (while the Maybach was still in production). Good overkill though, as it probably reduces the risk of the rectifiers and regulators overheating, so it will probably improve reliability in that oven of an engine compartment.

Nick

PS. Just remembered - I thought our cars used 210 amp alternators? Maybe there are various standards depending on market? Nothing much to worry about though - our alternators are still more powerful than anyone else's starter motors!

biker349

great write up.
thanks

biker349

okay, still researching. i believe the 150 amp has the plug for the alternator with 2 grooves on the bottom and one on the top. my 180 amp is reversed with 1 groove on the bottom and two on the top. i believe the plug will still work, but i don't know if this will reverse the polarity, or cause a malfunction. any ideas? i'm trying to locate a cheap 180 amp voltage regulator part# F00M255203. any help is greatly appreciated. you can find all parts for the 150 amp water cooled alternator. the 180 amp is almost impossible to find and it was produced at least from 2003-2006. go figure.