[C320-list] Hitachi Alternator Output Curve

[Jeffrey Hare]

Hi Karl,

External regulator would burn this alternator out pretty quickly.

   If you go with a High Output alternator that's capable of delivering
current in the 75-100A range continuous, this would knock down your charging
time to a few hours (in theory).  The Balmar as Dick suggests is a fine
alternator for the 75+A range.  I installed an AmpTech 125. I've seen over
110A out of it with pretty-much  discharged batteries.  Had the batteries
pretty much back in shape after a few hours.
 
   If you choose Orlando's suggestion of using the compact honda generator,
(which is a very cool generator, BTW) you'd be much better off with an
upgraded shore power charger. The Freedom 20 Charger/Inverter is 100A shore
power charger and has an 2kw inverter built in.  Has the added benefit of
giving you AC for short periods of time without needing to plug in the
generator. (www.BrokenLegDave.com has them for $859.00)

  The stock ProMariner is only a 20A charger rated at up to 480AH per day
theoretical. So, 50% discharged batteries would theoretically take ~12 hours
to fully recharge this way.  Your choice there would be whether to run your
engine with stock alternator for ~8-10 hours, or run your generator for
~8-10 hours.

To fully recharge a battery, you'll have to put back each and every amp hour
you consume from your battery, plus some.  

-Jeff


-----Original Message-----
From: Karl Mielenhausen _/) [mailto:kmielen at iwon.com] 
Sent: Sunday, May 21, 2006 4:37 PM
To: C320-List at catalina320.com
Subject: [C320-list] Hitachi Alternator Output Curve


My Japan Yanmar has the Hitachi 55 amp alternator (LR155-20). 

Has anyone out there with this alternator and a battery monitor actually
determined the output curve for this alternator?

For example: 40 amps for 20 min, then 30 amps for 20 min, then 20 amps for
20 min????

I'd like to determine how many amps I can put back into the batteries when
on an extended cruise away from shorepower. Would I be better off by
motoring 60 mins straight each day or two blocks of 30 minutes?

Also, has anyone fitted this alternator with an external 3-stage regulator?
If so, what sort of improvement have they seen?

I estimate daily consumption when cruising at about 110 AH.

Thanks for any info...



Karl Mielenhausen

2000 C320 Hull#690 "Silver Lining"

New Bern, NC

http://members.cox.net/mielen/

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