Unique Products for Your Boat
  • CMI-ED200-ER - 200A Large Frame Extreme Duty Alternator -J180 Mount

    $789.00 $599.00


     Click Here For International Shipment Info


    For the first time ever Compass Marine Inc. is offering a massive J180 large frame high performance externally regulated extreme duty alternator at sub $1000.00 prices. Our competitors start at $1200.00 and go up from there.

    After many months of testing various large frame J180 mount alternators  & components for performance and heat characteristics, Compass Marine Inc. is proud to introduce the new CMI-ED200-ER. This 200A alternator is a literal behemoth, similar to the massive alternators found on big-rigs, ambulance, rescue and other applications where high output demand, to run high amperage equipment for long periods of time, is required.

    IMPORTANT: This is not a small frame alternator and fitting it to many marine engines, unless it already utilized a J-180 mount large frame alternator, will require custom work on your end. The CMI-ED200-ER has a 15% restocking fee for fitment issues. Please measure twice and purchase once.

    The CMI-ED200-ER is the ideal alternator for charging large AGM, GEL or LiFePO4 battery banks while at the same time keeping costs to a reasonable level. CMI can control these costs because we build these alternators one at a time here in the CMI shop. The only thing we outsource on this alternator is the stator & rotor winding. With no other CMI alternator dealers to drive up the end user cost, our prices on externally regulated alternators simply can't be beat. 

    Pair the CMI-ED200-ER with a Balmar MC-614H and you're still under $949.00 for a 200A extreme duty externally regulated alternator!

    The problem with typical commercial and industrial duty-alternators is they are all internally regulated and not well suited to charging the expensive deeply cycled banks normally found on boats. While fairly robust, they are intended to power aux equipment on these rigs, not to properly charge the batteries, in a healthy manner

    Compared to typical small case alternator, with a maximum running temp in the low 200F range, the CMI-ED200-ER can be run at 255F +/- . This means you can actually raise the alternator temp limit on a Balmar regulator, not decrease it. The CMI-ED200-ER can deliver 125A at a typical idle speed (2000 alternator shaft RPM) and over 140A at a "fast idle" or about 2400 alternator shaft RPM.

    Features & Benefits

    • Dual internal fan design provides maximum cooling even in hot engine bays
    • We use high temp Kester Solder $$$ exclusively during the build process.
    • Smallest & most compact frame of any large frame J180 mount extreme duty alternator
    • Amazing efficiency. At upwards of 68% efficient this means less waste heat to dissipate and a cooler running alt
    • Massive 62mm pulley end bearing
    • Hot forged rotor poles for less magnetic noise
    • Can handle 10,000 RPM continuously
    • Drive end bearing fan keeps the bearing cooler so it lasts longer
    • External & internal bearing protectors keeps moisture out of the bearings
    • Brush holder seal and moisture protection
    • Direct mounted slip rings for less connections and better reliability
    • Massive 14mm slip rings means better contact and less brush chatter
    • 80A avalanche diodes mean longer life and better protection from load dumps
    • Massive rectifier heat sink means lower rectifier temps and longer life
    • Alternator shaft is 7/8" which is also .875" or 22mm


    *In order to keep costs down this alternator has not been spark tested for USCG compliance for use with gasoline engines.

    *Fitment is up to the purchaser. On most sailboat AUX engines fitment will require a custom made mount

    *This alternator does not ship with a pulley. Just let us know what you need and we can get you a price. We can offer dual v-pulley, 6 groove serpentine (custom), 8 groove serpentine or a 10 groove AltMount/Balmar type pulley.

    *Also available in a 250A model with a 3-6 week lead time for the custom non-stock stator & rotor winding.

    Questions: compassmarineservices at gmail dot com