Electricity

Solar Energy - Electricity - sample setup cost

Battery Power Management

  • Excellent explanation by expert - this post and rest of the thread. Why you want 6V in series, how to set generator to power battery charger (and not directly AC), how house battery can kill car starter bat.
  • % Of Charge and resting volts using $20 digital multimeter
  • All you need to know about batteries: Glossary and why AGM is best (can be charger much faster)
  • Keep batteries charged and clean; plus safety: remove all metals to avoid welds (including personal jewelry like rings).
  • Trojan recommends to charge max 10% of Ah (less when almost charged), so when charging by genset, topping off is slow charging = waste of fuel. Some people (with solar) charge only bulk (max) rate, and charge more often instead, if needed.
  • Ask dealer to keep your batteries charged while in weeks-long maintenance.
  • Taking care of your batteries and saving energy/water when boondocking.
  • Bigger gens are quieter and you may need them: A/C uses more energy in startup.
  • Intelligent charger can prevent fire caused by boiling up overcharged batteries.
  • golf-cart batteries can be replaced by cell, $200 for 225Ah. AGM are sealed (no vapors) for triple price.
  • Battery tips discharge to 80% or less
  • Adding batteries - place then close by, same health, bad one can take out a good one, and vent them.
  • Battery expert
  • Flooded lead acid batteries are either lead calcium "maintenance free" types, or lead antimony — has caps and need to add water periodically. Most deep cycle batteries are lead antimony, since the "maintenance free" types (lead calcium) are sealed, but have low tolerance for "deep" discharge (below 40-50%). Lead antimony has higher tolerance for deep discharge, but they self-discharge faster. On balance, lead antimony is better suited for RVs,
  • Gel Cell: Good for boats,replaced by AGM. (absorbed glass mat). Expensive but "maintenance free"
  • true way to know state of charge of a battery is to check its specific gravity. Troublesome. go by battery voltage: digital display. Get the battery "at rest". first thing in the morning, before first light if solar.
  • battery failure: Overcharging. Depends on temperature: less if hot, more if cold.
  • Buying batteries "H5" means battery was manufactured in August ("H") of 1995. Buy more recently manufactured of same date.
  • Batteries 101: types, care, charging and 102: multimeters
  • Good summary - capacity, advanced charging.
  • Life cycle - How discharge level (10%-50%-80%) has effects on battery lifespan
  • Why AGM
  • 3 stages of charging

Saving Watts

  • Extended fuel tank, inverters, saving wats - and use candles.
  • Microwave uses A LOT of amps. Incandescent light bulb too: fluorescent lamp is better and LED is best.
  • unplug unused appliances - they draw (a bit of) power even off.
  • Clean your battery - debris can leak currents, even small leaks will kill battery.
  • Charge all small battery powered items ( cell phones, laptop batteries etc.) when driving
  • Fantastic fans work with very low power draws and move an amazing amount of air cooling your rv boondocking rig.
  • If you pay for power in RV park, make pic of power meter when you hook up, and unhook,

Inverters

  • Inverter do and don't tips
  • maybe having couple small ones is better that single big. Big 2000 watt takes 1% to power small appliance which needs 30 watts.
  • Inverters draw a small amount of power, even when there are no loads. Always switch them off when not in use
  • Most power inverters are “modified sine wave”: OK for micro wave. But for TV, computers if you are have problems get more expensive ‘pure sine wave’ inverter.
  • Inverters also will protect delicate electronics from power surges. Run computer on the inverter, even when plugged into shore power.
  • Autoformer When the RV park power drops it boosts the voltage up to 10% by lowering the amps. Less than 104 volt would kill your A/C, $3K to repair.
  • Inverters and chargers - 3 stages with lowering voltage to avoid boiling. Or at least set a timer.
  • Charger with Equalizer - for wet batteries.
  • Inverter with 90% efficiency: avoid if not listed (too low).
  • Amp hour meter: measures amps in and out. Helps avoiding discharge below 50%.
  • The typical vehicle alternator stops charging as soon as the vehicle battery is fully charged. Regulator shuts down the current and house batteries are no longer charged. A quick solution is to turn on the headlights: regulator to allow the current to flow again, and the house batteries will be recharged. A complete solution would involve installing an after market three stage regulator.
  • Turn off inverter - don't waste amps.
  • Microwave is rated in "cooking watts". Very inefficient, can take twice the power to deliver the "cooking watts". "800 watt microwave" likely requires 1600 watts of power to run.
  • charge controllers — "on-off" type: set at about 14.8 volts. When the voltage reaches that level, the controller then completely cuts off all current. They can be very hard on batteries, reducing battery life. Pulse width modulation is better.

Tips

  • RV outside A/C plugs are exposed to weather: Home Depot sells male and female plug ends (to repair an extension cord). I filled them with a silicon compound, to keep them water tight, and plug in.
  • Extension cords - with such big amperage, improper cord is fire hazard. Too long cord can lower voltage - and damage appliances.
  • Pull all the shore power cable out of the compartment - coiled in produces heat.
  • If your fuses are not labeled, pull them one-by-one and label which appliance stopped working.
  • Wire connectors able to withstand RV vibrations
  • Using multimeters - basics required from each RVer.
  • In parks with marginal voltage, the closer your site is to the panel box, the higher voltage you'll have. Avoid sites which are at the far end of the electric park's installation.
  • Surge Guard - protects from surge and undervoltage.

Light bulbs

  • pro-con of types LED are sensitive to over-voltage. xenon bulb will last longer than the equivalent halogen bulb, and is less sensitive to "finger grease".
  • replace with a portable LED, clamp on, all powered by rechargeable batteries.

Generators

  • Cheap Chinese gensets huge thread
  • Generators - same fuel as MH - even diesel. Need to work at least 2 continuous hours per month under load. Always run on low or no load for several minutes before shutting down.
  • used generator with very low hours: in worse shape as one which has actually been used.
  • Autoformers — can make up for a 10% drop in voltage.

Modifications

12 Volt debate: Get a book Living on 12 Volts with Ample Power. You can go to amplepower.com to see if they are still selling it (it's like 20 years old) or you can search the Internets to see if there's a reasonably priced used copy. It's basically a whole book about adding up your loads and meeting them with battery power through an inverter.

There's also a companion publication (about 50% overlap) titled Wiring 12 Volts for Ample Power which would be worth having if you also found a relatively cheap copy of it.

Blurbs for the books: http://www.amplepower.com/primer/.

a battery separator has relays, and thus has no voltage drop across the contacts. The battery can then be fully charged. isolators use semiconductor diodes, and have up to a 1/2 volt drop across the diode.

Sportsmobile has been using battery separators.

Most appliances won't be able to tell the difference between modified sine and true sine (If you run a stereo or a traditional TV you may get some static in the signal) and you won't need true sine unless you want to power something like an oscilloscope in your van. The power cords for laptops, my PS2, and your xbox all convert the power into DC before it even gets into the unit, so you won't notice a difference between sine and modified sine.

The most I've seen people do on a budget is maybe purchase a separate 300 watt pure sine inverter just to run a desktop computer off of if they don't have a laptop in their bus.

many disagree:
http://www.busconversions.com/bbs/index.php?topic=9475.0

Pay special attention to "boogiethecat"s posts…..

If that's not good enough, google "square VS sine wave"….

when you throw in the number 2000 watts your not talking simple. For this kind of capacity you are going to need at least 2 batteries and I would suggest 4 six volt battery's. If you want simple I would suggest 1 Wal-Mart marine battery, No more than a 700 watt inverter and plan to draw no more than 200 watts except for short burst. This will run your computer, charge your phone, play a small TV, and provide a couple small draw lights. You can't do all at the same time for long without needing more batteries. I also suggest you get the battery box that is available for the marine battery to store your battery. when trying to decide if and where you will have enough space you can measure one of these battery boxes and build your shelves to fit over it. That inverter and all batteries need to be close together. I use sticky back Velcro to mount mine right on top of one of the battery boxes. In my Astro I use one marine battery, a 750 watt inverter and a 100 watt inverter. The 750 watt is the one Velcroed to the battery box and the 100 is wired right out the back of this inverter. I have two inverters to size the inverter to the job.

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