Jim:
Car batteries are designed for one thing and one thing only – delivering a bunch of power for a very short period of time. Said time is measured in seconds, not minutes, hours, or days.
I have been living “Off the Grid” for fifteen years, and can assure your readers that vehicle batteries can only handle 3-5 complete discharges before they are useless, i.e., after but a few discharges they cannot be recharged and expected to hold said charge. Ergo, they are the wrong choice for any task where discharge exceeds the constant charging input into the battery. They will not last, and the monies and the time procuring and cabling such will have been wasted.
If one intends to utilize batteries and a charger of whatever source to power lights or equipment of any sort, only use “Deep Cycle” types as the plate construction used in these is designed for multiple deep-discharges. The number of discharges varies given the size of the battery itself, and can range from as few as 100 to well over 2,000. Yes, in the case of batteries, size matters.
Another little hint: When engaged in the mathematics of power generated in relationship to end use, whether from solar, microhydro, wind, or fuel powered generators, remember that when using a battery to “store” generated power, factor in a loss of 6% of the power produced due the requirements of the chemical reaction in the battery. Period. And never forget that “Volts X Amps = Watts”. If you don’t model your production and usage with these numbers in mind, say goodbye to your batteries.
On the way out the door, one more bit of advice, this on “Phantom Loads.” Many of the appliances we buy today are never actually “off”, even though one believes such is the case. A few decades back, the appliance manufacturers decided to stroke our egos because having to wait a few seconds for an appliance to “warm up” was frustrating. Now such a wait would border on a personal insult. We demand “instant on” from everything, and this comes with a price. Even “off”, many of your appliances consume power. Either you pay the power monopoly for it, or if “Off the Grid”, you deplete and perhaps even destroy your batteries.
The easiest way to find how much your favorite appliance is robbing you is to buy a little device called a Kill-A-Watt [electricity usage monitor]
Solution? Whether “Off the Grid” or dependent on a power monopoly, put all such appliances on power strips, and when you want them truly off, shut down the power strip. Then “Off” really means “Off”. There’s no point in paying for something your aren’t using, and if out there pioneering, ignoring this will destroy your batteries, Good Luck! – J. Mo
James,
I noted with concern one item in the recent blog article: How to Capitalize on Urine, Car Batteries, Wood Ashes, Bones and Bird Schumer, by Jeff M. He recommended using car batteries for lead to cast bullets from. As a caster myself I have learned that this is an extremely hazardous thing to do. The lead plates in car batteries are impregnated with arsenic and calcium to aid the the chemical reaction to generate electricity. Melting these down will generate arsine gas which is highly poisonous. He also recommended using lead wheel weights. [Traditional lead alloy] wheel weights [made before the recent switch to zinc] are the preferred metal for most bullet casters. While they contain about a quarter of a percent of arsenic they do not contain calcium and do not generate arsine gas when melted. Safety First!
God Bless, – Jim E.