battery operated gadgets

Re: battery operated gadgets

I am not quite sure what you are asking for... For AC power, a Kill-a-Watt Meter (versions also now available for other countries) is a great start.

For smaller DC loads, one of these Amp*Hour/Watt*Hour meters used by RC guys (Remote Control planes/cars/etc. hobbyists) would be handy too.

Looking for battery powered appliances (like the old Boom Boxes--portable radio/tape/cd players) would usually indicate something designed for more efficient power consumption.

Lighting--there are lots of options out there such as CFL and LED... However, they vary so much in consumption vs light output vs beam characteristics--That you almost have to purchase one of each and test with a Kill-a-Watt or DC Amp*Hour/Watt*Hour meter to see how much power each unit actually uses vs how much use you get from it.

And making your use as local as possible... A CFL may be the better room light. But an LED based lamp would be better for spot/work bench lighting.

I stopped using the big stereo (my old one even used 20 watts on standby) and replaced it with a cheap battery powered AM/FM radio with ear buds and uses a single AAA or AA battery.

Much in the way of conservation requires some modifications to our own behavior--as well as doing our own testing/qualification for efficiency based on yours or mine specific uses.

-Bill

Re: battery operated gadgets

When I was young (may decades ago ), my parents simply used a hand cranked coffee grinder for their coffee (frequently powered by us kids fighting for the chance to turn it).

For a small device like a coffee grinder, assume that it takes 100 watts and runs for 1 minute:

100 watts * 1 min * 1 hr/60 min = 1.67 Watt*Hours = 0.0017 kWhrs per use

However, to heat your 2 cups of hot water... Say 1,500 watt electric tea kettle for 5 minutes:

1,500 watts * 5 min * 1/60 = 125 Watt*Hours = 0.125 kWhrs per two cups

And, if you want to relax in a warm room in front of an electric heater for an hour while enjoying the coffee+paper/laptop reading Google News:

30 watts * 1 hour = 30 Watt*Hours = 0.03 kWhrs for the computer

1,500 watts * 1 hour = 1,500 WH = 1.5 kWhrs for 1 hour of electric heat

So--you really need to evaluate each usage for a cost/benefit ratio... $1-$2+ per kWhr is a realistic estimate for the cost off your off-grid system power (remember that battery needs to be replaced every 4-8 years or so--there is a definable ongoing cost for off-grid power). Using alternatives for heating (propane, solar thermal, etc.) is generally much more cost effective vs using solar electric/PV panels.

The coffee grinder, less than a penny to run it per day. The laptop, perhaps $0.03-$0.06 per hour. The electric heater (I know, just an example) will cost $1.50-$3.00 per hour of use.

Since you have a a solar panel + battery + inverter (?) -- you can estimate how much useful power it will generate per day, and plan your loads accordingly. Some days, you will generate more power than average, and others less than average. It does require monitoring of the battery state of charge + available power from the panel(s) to ensure that you do not draw more power than is available over time (deficit charging) and kill your battery in a few months.

The Kill-a-Watt and Amp*Hour meters I suggested earlier will help you with load planning and monitoring.

A Battery Monitor will help you manage the battery state of charge (and a good quality hydrometer+thermometer if needed, and is flooded cell battery) help you better understand your system and your eventual needs (assuming that you want to go with a larger off grid system in the future).

Here is a nice thread about installing solar in a small RV Trailer (Kevin from Calgary). Includes photos and links to video (including a Battery Monitor).

-Bill