hey alco or anyone knowledgeable about deep cycle batteries and inverters -
I have wanted to do just that - but am totally electronics ignorant.
I hear and read stuff about the batteries "off-gassing" and they need to be "vented", etc. Can you please give me the skinny on all this? You can PM me if you want. Watts, volts, etc. is beyond me.
Are all "marine batteries" deep cycle?
Any experienced suggestions for brands of batteries and inverters, and specific battery-inverter teams to use for general inside the house power outages would be much appreciated. Thank you very much.
look at eham.net, they have a lot of info about aux power and generators, hams want to be on the air in an emergency, they have lots of plans and how tos for ham station power, most just keep a deep cycle battery, these come in two common sizes 24 and 27, the 27 is 100 amp/hr rated, is the one most used.
you can use any automotive battery charger for them, you can hook them up with jumper cables to your car and your car will charge them. you can float them on your ham radio power supply to charge them, the small generator i mentioned has a 12 v output to handle battery charging. next figure out what you want to run and get an inverter large enough to give you more watts than you need. watts=volts X amps , so look on the device you want to run it will be rated in amps or watts, if it is amps multiply by 110 (volts) and this is the watts of the device.
for things with motors you will need extra starting power a motor uses a lot more power to start than to run once it is started so figure more power,battery will not last long with a motor load on it, so unless you are planning to make a large battery bank forget the frig/ freezer. then buy a inverter large enough to handle the watts of power you need.
plan on not discharging the battery below about 1/3 or its rated amps or about 10.5 volts (as the battery is discharge the voltage drops- you start with about 13.8v for a fully charged battery), this can damage the battery and reduce its life, also slow discharge is better than rapid discharge. slow charge is better than rapid charge, battery should be charged at about 10%
of its rating so a 100 amp/hr battery should be charged at about 10 amps. with the type of system we are talking about you are just making a large computer UPS, you can add as many batteries as you want hooked in parallel to add all the power you want, and can add to the system as finances permit.
the average 100 amp /hr deep cycle battery is about 70-80 bucks, there are a lot of more expensive battery types out there but lets keep it simple for now. keep these batteries fully charged and they will last you 10 years of so. not all marine batteries are deep cycle there are marine starting batteries, not good for this use, you want deep cycle, the thinner lead plates in starting batteries will not hold up to deep discharge. off gasing is a problem is you charge heavily in a confined space, so they need ventilation, the hydrogen will build up and a spark can cause an explosion, keep your batteries in an open area. this is not a great big problem, charge slow, dont put the batteries in a closed box, allow for ventilation.
the good news is that many inverters are set up to automatically shut off at 10.5 volts. some will auto charge your battery, some will switch from line power to battery power on their own and back. some are modified sine wave some are pure sine wave, if you are running a lot of electronics you want a pure sine wave, if you are running some lights and a fan it wont matter much.some guys will buy a small pure sine wave for electronics and a larger mod sine wave for larger items. the mod sine wave are much cheaper than the pure sine wave.
there is a lot more but this will give you an idea as to what you are looking at.
alex
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(plus a gun or two)