| Power Budget: Ranger 29, solo San Francisco to Hawaii in 1996 | ||||||
| Equipment | amperage | useage/day in hours | voltage supply | amp-hours/day | total amp hours over 16 days | |
| Running Lights: 2 bulbs | 1.6 | 8 | house | 12.6 | 204 | |
| masthead light: 1 bulb | 0.8 | 8 | house | 6.4 | 102 | |
| masthead strobe | 0.8 | 8 | house | 6.4 | 102 | |
| Interior Lights | 0.8 | 2 | house | 1.6 | 26 | |
| VHF | .25/5 | didn't use it | ||||
| GPS | ? | 1 | portables | |||
| Bilge Pump | ? | didn't use it | house | |||
| HR radio receiver | ? | 1 | portables | |||
| Knot/Log | self-generating | Total 434 amps | ||||
| Depth | didn't use it | |||||
| battery capacity: 240 amps | ||||||
| 3, 80 amp-hour batteries | ||||||
| With the above minimal-electricity-use scenario, steering was done entirely by Navik Windvane or by hand. I had no SSB radio. | ||||||
| Interior light at night was provided by flashlights. I had a small 5 watt solar panel, which supplied about 3 amps a day and 50 for the trip. | ||||||
| I ran the lightning charger once for about 3 hours about 2/3rds of the way through the trip. It has a 30 amp alternator on it, so that put | ||||||
| 90 amp hours back in my batteries. 90 + 50 + 240 = 380… | ||||||
| So, in other words, somehow I got to Hawaii in one piece using quite a bit less juice than I budgeted for, here. | ||||||
| Power Budget: Santana 3030, solo San Francisco to Hawaii in 2004 | ||||||
| Equipment | amperage | useage/day in hours | voltage supply | amp-hours/day | total amp hours over 16 days | |
| Running Lights: 2 bulbs | 1.6 | 8 | house | 12.6 | 204 | |
| masthead light: 1 bulb | 0.8 | 8 | house | 6.4 | 102 | |
| masthead strobe | 0.8 | 8 | house | 6.4 | 102 | |
| Interior Lights | 0.8 | 4 | house | 2.4 | 38 | |
| VHF | won't use it | |||||
| GPS | portable batteries | |||||
| Bilge Pump | won't use it | |||||
| SSB | 1.5/25 | 1.0/0.25 | house | 8 | 128 | |
| Knot/Log | self-generating | |||||
| Depth | won't use it | |||||
| Autohelm (ST 1000/2000) | 1 | 10 | house | 10 | 160 | |
| Leptop PC | 4 | 1 | house/battery | 2 | (9 days only) 18 | |
| Sat Phone | 1 | portables | ||||
| Total: 752 amps | ||||||
| Notice that adding the autopilots and moderate useage of the SSB has nearly doubled my energy requirements. | ||||||
| My Daily energy consumption is something on the order of 90 amp-hours a day, or a bit more than draining one battery. | ||||||
| This means I really need to charge every day either by running the engine or having a significant solar contribution, or both. | ||||||
| The laptop PC will be used every day for the first 8-9 days to download Weatherfax. After that, the decisions have been made and there's not a lot | ||||||
| you can do about it, so... I'm assuming it will take about an hour to download the WXFX and stare at it and make decisions. | ||||||
| The big unknown is whether I'm going to do e-mail out there. Right now, I doubt it. I assume I'll hand-steer about 6 hours a day. | ||||||
| The windvane will steer about 6-10 hours a day. The autohelms will steer about 6-10 hours a day. The ST 1000/2000 are actually | ||||||
| rated at 500 mA, but let's assume they're working hard, so 1 amp draw. When it's dark outside, I like it dark inside. That's part of the whole | ||||||
| thing, so I won't run interior lights that much. I assume I'll have a solar panel that's a little bigger than the one I had in 1996, and I like the flexible | ||||||
| ones so let's say I'll be generating .6 amps, 10 hours a day with the medium-sized one. That's 6 amps a day. | ||||||
| Generating Capacity | ||||||
| Storage…240 amp-hours…3, 80-amp hour batteries, two primary, one "spare" | ||||||
| Solar input over 16 days, assuming 6 amps/day = 96 amps…OK, call it 100 amps. | ||||||
| Ok, the "spare battery" is a truly a spare. I'm starting out with 160 amps in the two working batteries. That means I need to generate a minimum of 600 amps | ||||||
| while I'm out there from the engine or other source, probably at least 30-40 amps a day to keep from draining one battery.. | ||||||
| About 100 of those come from the solar panel, which leaves 500 to go. | ||||||
| If I use the engine and that 35 amp alternator (which really puts out more like 30 useable amps), that means I have to run the engine for 17 hours, minimum. | ||||||
| I really need to charge with the engine every day even if the solar system is putting out what it's supposed to. | ||||||
| Adding another solar panel (at $177) should put another 6 amps a day into the batteries for a total of 12.. Considering that I hate to run the | ||||||
| engine, maybe I'll buy another solar panel. Well, except that 12 amps a day is still really not enough. I need to put more like | ||||||
| 80-90 amps back into my batteries each day, really, Then again, running the engine for three hours burns 1 gallon of fuel, or less | ||||||
| and at $1.50 a gallon, engine time is cheap compared to solar. My primary fuel | ||||||
| tank holds 11 gallons, which is enough to get me there, especially if I carry another 5-7 gallons in a jerry can on board. | ||||||
| Also, the rate of transfer of electrons is SO much faster using the alternator that is solar worth the money? | ||||||
| I can also just forget using the autohelm and run the windvane all the time. Two solar panels plus using the Navik, | ||||||
| running bare essential nav lights and the hand-held strobes….the panels plus the Lightning generator should be able to keep up if the engine quits. | ||||||