We have a remote piece of heavily wooded property.We are working on putting a Mongolian Ger on the land.We plan on living in it full-time and add solar as our means of power.In the meantime we commute daily.Would it be possible to power our tiny homestead with batteries that we recharge daily in our two cars.Or we also have the option of charging them at our jobs.Is this a feasible option?
Yes, it will work in the short term. Your car alternator system is regulated and is not designed for deep charging, it will only surface charge.Car batteries are not a deep cycle battery and are designed for constant recharging. Your batteries will have a much shorter life than if you used a trickle charger at work. What you will eventually need are large deep cycle batteries, they are made to work with a off grid system. A small deep cycle sealed battery and a charger made for sealed batteries used at work will get you by until you have your solar system up and running. But be careful !!! carrying your battery from car into your job is liable to get acid on your clothing and ruin it ... also carrying batterys is heavy work!
Not all who wander are lost... J.R.R. Tolkien
posted 4 years ago
Excellent points.I had wondered if there are very good solar batteries that we could charge at work.So when we are able to afford the solar panels we would not have the added expense of new batteries.We are not planning on using an enormous system.
We could use a dolly or cart to haul the batteries from the yurt to the car and the car into the building at work.Also how would the battery know how it is being charged?Is the power not converted before it is used to charge?
If I understand you correctly ,you are asking about the charge rate ? In your car, a regulator allows the alternator to charge the battery hard for just a few moments after starting. This replaces the power that was used to start the engine. After that your regulator severely limits the amount of charge allowed into the battery, just enough to keep the voltage up. This does not work well for charging off grid batterys . Buying proper deep cycle batteries
is a must for off grid use. Having a proper charger for your deep cycle battery is also a must if you want them to last . As far as what brand of battery to buy ? The choices are endless. I have just been investigating a new style of off grid battery that claims to be impervious to cold! A silicon salt battery. If you plan on a small power system and do not need cold resistant batteries then a "Trojan T 105 " size battery (golf cart size) could be a good match for you. You do not mention your location , things available here in the US may not be available other places. Here is a link to my favorite alt energy catalog , it is chock full of information on batterys and all other things off grid.http://www.backwoodssolar.com Good luck with your new home.
You want to be using a deep cycle battery for your off grid out of car power consumption.
Many cars come with two batteries - one for starting the engine and one for low current uses such as running interior lights and satnav/entertainment systems. This second one is a deep cycle and the car's charging system is built to charge it safely.
If you have an older/basic car with just one battery, then the problem is that the alternator is probably putting 40-50 amps into the battery whenever the battery's voltage is below about 12.5V. This is too much for most deep cycle batteries. Rule of thumb is max current in Amps should be no more than 1/5 of the battery capacity in Ah.
E.G. 100Ah battery could be charged at max 20A. But check your battery because some prefer even lower currents.
You can buy charge regulators very cheaply that work from a car, and are designed to safely charge a deep cycle batt. Buy one, and problem solved. But you will need to run your car for several hours to charge from nearly empty to nearly full.
Thank you all for the responses.If it takes several hours to charge a battery how do I find out how long it will take to discharge a battery.I am assuming that our biggest draw will be a television and a gaming system.We also may need to run a dehumidifier and some lights.I am just at the beginning of this journey so I still have so many unknowns.
Sadly vicki it doesn't take long at all to discharge a battery. How long is the million dollar question that every person off grid wants to know. How big your battery bank is determines how long it takes to discharge. You must be careful which appliances you own, some draw large amounts of power to do the same thing another might do with a fraction of power. winter will use more power than summer. Lighting is a big one... led lights use a fraction of the power that an incandescent light does, compact fluorescent is better but not good enough. My old smaller tv used 5x the power than my larger new one does. Refrigeration / freezing should be in your thoughts as well... consider propane for that. Steve is correct with what is available and his guess of several hours to recharge. If you are traveling to work several hours a day then that could work for you. If you are idling your car at home it will cost more in fuel running your car than a small gas generator would.
If you are going to live in a ger, will you also have light power requirements?
If you base your system mainly on usb powered devices and use several batteries designed to carry multiple recharges for them, you can easily recharge them most anywhere, including your car. An additional benefit, when you ask to charge at work or another stop or visit, you are presenting a cleverly employed piece of common consumer electronics. If you ask to charge a power supply for "personal electronics", most people will be very understanding, if you tote in a dolly with a couple golf car batteries... results may vary. Its like when we tell people we have no television, we have been offered soo many tvs!
Lighting, water pumping and communications power is quite easily within the range of your resource, commuting and destination charging. You will likely need a larger battery for long duration whole-room lighting and pumping shower water, but every home operates differently, foot pump faucets, gravity, daylighting only, you can never tell how someone lives.
A couple small deep cycle batteries, say 35 or 40 ah, or maybe one or two larger, 80-100ah batteries could work for spartan services than could actually be pulled off with maximum effect on your homestead situation. I have made this work. The reason for two batteries is for a relay of electrons. A battery of this size can be charged by a car through an appropriate charger. If you can adjust charge current, you can spread the charge demand on your car electrical system over time instead of drawing heavy.
Another way is the use of cordless hand and outdoor power tool battery and charger systems.
This is especially cost effective if you use electric power tools, especially outdoor yard tools, chainsaw, lawn mower, etc. The main thing i like about this is that they charge quick when they are lithium or even nimh. Most of these chargers draw between 60 watts 80 watts and max out around 200w. This is very doable with a vehicle set up and arent too crazy to plug in for opportunity charging, even in some public places. An EGO, GREENWORKS or RYOBI mower/chainsaw battery holds a lot of power, lights, comms, showers! This is a great investment in equipment if you intend to go with solar electric, on grid and especially off grid.
In the photo is a system that i use for portable power. It was made from scrap materials and equipment and i built in a couple hours for someone leaving in a hurry for burning man. I got it back and i use it for powering our house during system shutdowns for battery maintenance and as a general back up. It is very basic and has no exotic parts, no bells and whistles, just power in 5vdc, 12vdc and 120vac with multiple charge inputs and power outputs. It has an inverter, aa/aaa battery fast charger, lighter plug, 12vdc common electronics power jack, basic fusing, solar charge control and could use a multi voltage converter for laptops and such, and also, a battery and input switchgear.
Rv/Marine electrical equipment from blue sea, and parts from powerwerx are great for a nice project, especially the blue sea fuse block distribution with ato type fuses.