Our boat came with an internally regulated, Leece-Neville 105 amp alternator. It couldn’t keep up with the high charge acceptance rate of our new 500 Ah LiFePo battery bank; it worked too hard and got too hot and finally quit on us. Plus, it looked like it had been sprayed with salt water at one time.
So when our alternator took a crap, we already had a pretty good idea of what we were going to get as a replacement. We’d briefly done some research on alternators a few years ago and had decided on a Balmar. We went with Balmar because they’re a proven name with a long track record in the marine electrical industry. This alternator is not some glorified, repackaged automotive alternator. It is designed and built specifically for the marine environment.
Spinning one of these high output alternators requires upgrading the drive belt to serpentine. On our Perkins 4-108, that means also changing the water pump with a serpentine pulley machine-pressed in place. And also installing a new lower pulley on the crankshaft.
What We Bought
We bought a 60-series Balmar 150 amp alternator, MC-614 programable smart external voltage regulator, and a Balmar serpentine pulley conversion kit. The external voltage regulator has programable features that protect the alternator, the battery bank, and the engine from damage. These high output alternators can reach temperatures of over 220 F, and remotely mounting the regulator helps protect the sensitive electronics inside from failing.
We ordered everything from PKYS in Annapolis, and it shipped directly from Balmar. If you’ve seen our New Alternator Part I video, you know that the crankshaft pulley didn’t fit. We contacted Balmar and sent everything back to them. They then sent everything back to us with the explanation that the crankshaft pulley was within their machining tolerances. So we were on our own to make it fit.
Making it Fit
Instead of taking it to a machine shop and having them grind it down by 0.015 of an inch, Rich taped some emery cloth to a socket attached to his drill, then spun it through the opening very slowly. It worked and the pulley slides on correctly now.
The next hurdle was the engine bracket. First, the new alternator has a 1″ or 2″ foot to bolt to the bracket. Our bracket has a 2″ opening. Actually, it’s a little larger than 2″ and the Balmar foot and bushing is a little under 2″. So we had to add a washer to make it fit.
Second, the bracket itself was a 1/2 inch off. Rich had to weld a piece of metal to the end and drill the bolt holes a little longer. Once bolted together it fits correctly.
Resources
Thankfully we didn’t have to reinvent the wheel on this one. RC Collins at Marine How To has some great articles on upgrading marine charging systems and I refer to that site often for technical information.
- Marine Alternator Installation – Tips & Tricks: https://marinehowto.com/marine-alternator-installation-tips-tricks/
- Programming a Balmar External Voltage Regulator: https://marinehowto.com/programming-a-balmar-voltage-regulator/
- LiFePO4 Batteries On Boats: https://marinehowto.com/lifepo4-batteries-on-boats/
