Not about coffee, but… There are now available vacuum cleaners that run off 18 V (20 V?) used for power tools (you can get a Dyson version, but then the whole discussion about saving costs is out to lunch). If you have a power tool on board, a vacuum like that can save your house battery a bit. I happen to have all my power tools from Ryobi, so I got a Ryobi version. Works well enough that I use it occasionally at home, as well.
Marek From: Della Barba, Joe via CnC-List <cnc-list@cnc-list.com> Sent: Wednesday, October 18, 2023 3:10 PM To: Stus-List <cnc-list@cnc-list.com> Cc: Della Barba, Joe <joe.della.ba...@ssa.gov> Subject: Stus-List Re: [EXTERNAL] Re: Sizing an inverter You can, you just have to think it through. My wife can dry her hair, that draws about 50 amps for 5 minutes or so. I can’t run my cabin heater at 500 or 1000 watts off the battery, it would run the battery dead before the boat got very warm. Given most of our C&Cs were designed to be relatively light boats without huge battery banks, we are mostly a poor fit for trying to use high-draw AC house appliances running off of batteries. I use an AC vacuum and an AC coffee grinder, but I don’t try and use an electric coffee pot. Using the stove is far more efficient as far as turning fuel into hot water. What is it you want to run on the boat? Joe Della Barba Coquina From: Richard Bush via CnC-List <cnc-list@cnc-list.com<mailto:cnc-list@cnc-list.com>> Sent: Wednesday, October 18, 2023 8:56 AM To: cnc-list@cnc-list.com<mailto:cnc-list@cnc-list.com> Cc: Richard Bush <bushma...@aol.com<mailto:bushma...@aol.com>> Subject: [EXTERNAL] Stus-List Re: Sizing an inverter Paul, If I understand your point, it is that we shouldn't be relying on battery power for any appliances or coffee pots...etc.; is there any alternative that doesn't involve solar? thanks! Richard 1985 C&C 37 CB; Ohio River, Mile 584: Richard N. Bush Law Offices 2950 Breckenridge Lane, Suite Nine Louisville, Kentucky 40220 (502) 584-7255 On Wednesday, October 18, 2023 at 07:12:19 AM EDT, Dreuge via CnC-List <cnc-list@cnc-list.com<mailto:cnc-list@cnc-list.com>> wrote: Hi Chuck, First off, 12V * 100 A*hr = 1200 W*hr. But keep in mind that A*hr battery ratings for a 100 A*hr battery is tested typical at 5 amps(or 0.05C). That is your 100 A*hr is 5A * 20hr. At this rate the battery is only providing 12.5V * 5A = 63 Watts. At higher current loads, your effective battery capacity will be much much less due to Peuket Effect losses. In fact, a 100 A*hr rated lead-acid battery at 100 amp load would only provide about 20 A*hr of energy(and lots of heat). To add to the insult, lead acid based batteries like AGM should not be depleted below 50% capacity to limit damage, so reserving 1 battery for start leaves only 50 A*hr for your house bank at loads of about 5 amps. At a 20A load, the 100 A*hr (50 A*hr effective) only provides 60 A*hr (30 A*hr effective). That’s about 30 A*hr / 20A = 1.5 hrs of use. A 1000 W inverter could draw a max of 1000W / 12.5V = 80 Amps (but likely higher due to a voltage drop). This would drain your battery in 6 - 10 minutes. I gave a talk to some local Hams about Solar Off-Grid Systems. I posted the slides on my blog (see link below). On slides 5 & 6, I discuss battery discharge capacity and bank sizes. https://svjohannarose.blogspot.com/2021/10/solar-off-grid-system.html On Johanna Rose, I have a 2000W inverter charger. When I run my microwave, it draws about 100A from a 560 A*hr LiFePO4 battery. Like Dennis, I have my inverter connected to my panel powering all AC loads except for my A/C unit and water heater. The inverter has a built in transfer switch which automatically (and smoothly) transfers to shore power when available. - Paul E. 1981 C&C Landfall 38 S/V Johanna Rose Fort Walton Beach, FL http://svjohannarose.blogspot.com/ On Oct 17, 2023, at 7:27 PM, via CnC-List <cnc-list@cnc-list.com<mailto:cnc-list@cnc-list.com>> wrote: OK, an DC/AC Pure Sine Wave inverter looks attractive I've heard some boats have 1000 watt, some 2000watt and some 3000 or more. What size inverter is right for a boat equipped with two 100Ah AGM batteries? One battery provides 12v x 100ah: 1200watts. My system can provide 2400 watts but I usually reserve one battery to restart the engine and run on the other battery. Does the inverter get fed from a bus common to both batteries, or to the selector switch marked, "Off, 1, both, 2"? Thanks, Chuck S Please show your appreciation for this list and the Photo Album site and help me pay the associated bills. Make a contribution at: https://www.paypal.me/stumurray Thanks for your help. Stu
Please show your appreciation for this list and the Photo Album site and help me pay the associated bills. Make a contribution at: https://www.paypal.me/stumurray Thanks for your help. Stu
