LightningSafety for small sailboats

P-14
P-15
HMS-18

P-15

• P-15 wiring diagram from Bill Nolan

P-19

• Wiring, electrics, power consumptions, charging systems, etc.

Lots of battery and charging info at batterystuff.com.

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johnb210: Kerrie Lynn II mods - Scroll down to the bottom for a discussion and data of P-19 electrical consumption

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From the Trailer Sailor BBS:
Ray, P19 #953 "Water Wings", Lake of the Woods asks:
I have a Honda 8hp outboard on my P19. I recently stuck a voltmeter (set on the 20 range) into the output socket on the motor while it was running at medium throttle. I was unable to get any voltage on the meter although I could measure the battery voltage on the cord leading to my battery. This led me to believe that my motor is not charging the battery. I checked the fuse on the motor which seemed ok. Any comments or ideas short of bringing the motor into the shop?

mgpalmer: Try repeating your voltage measurement using the AC setting of your multimeter. It's quite possible that you were measuring the output before the rectifier, and if so, you will only see floating AC at that point.
You should always get a voltage measurement where the wires connect to the battery — you're simply measuring the battery voltage. This measure will be in the 10-12-13 V range when not charging, depending on battery state, and in the 14-16 V range when charging.
A much better measure of the charging state is to measure the current into the battery. This requires breaking the connection and putting a meter in series with the battery, with multimeter set in ammeter mode — a good place to do this is to remove the fuse and put the ammeter across the fuse connectors. I'm not sure of this particular charging circuit, but I suspect ~4 amps of charging current would be possible (order of magnitude guess).

Charging Systems

Motor Driven

Refer to Fig. 28 below, a wiring diagram typical of small two (or four) stroke outboard motors. Click the image for full sized version.

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Solar

Regulated or Unregulated

Shore Power

Single and Dual Battery charging

Combined Systems

It is possible to combine some or all of these methods in a boats power system.