Two alternators vs one big fat one?

[halcyon]

Any opinions from the cognoscenti about the virtues or otherwise of having two 80A alternators (say) rather than a single large one (120-150A for example)?

Our 54HP Yanmar drove a 110A Balmar alternator until it unfortunately departed for the great alternator party in the sky and we were faced with a bill of about £800 for a replacement. In the end we found a 95A one for half the price but really with a 550Ah house bank we need a bit more than that so given a bog standard 80A alternator can be had for less than half that would it make more sense to modify the engine mount and have two of those instead?

Is this easy/practical? Are there kits around to do it or is it a custom job?

At least if one gives up there is another one to limp along on.

Back in the 80's we supplied a lot of systems to Sealine and others that had twin engines with own battery and a service bank. The VSR allowed each engine to charge it's battery then the service bank, so both charged service bank. This worked fine as back then alternators were small, thus giving a slower charge rate and slower voltage rise. Once you got to the threshold of the lower regulator voltage it would start hunting then stop working, leaving the higher set one to do the work. These systems are still working after 30 years without a problem, so the theory worked.
Balmar do, or did a regulator that had outputs for two alternator drive circuits, thus both charged without hunting or one dropping out, but the cot was very high.

Brian