Battery recommendations needed

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Bill Watson
Bill Watson Registered Users Posts: 4
I'm pretty scared of getting shocked so I've always steered clear of electrical work.
I'm an old carpenter and I'm used to risking my life working way up framing roofs but a little shock?......terrified. O well.

I finally decided to bite the bullet and get set up for emergency electric so I did some research and found the great stuff everybody says about Northern Arizona Wind & Sun. I shopped around and kept coming back here and just bought their RV/Van Kit With 140 Watt Module and MPPT kit and expect delivery this Monday.

I'm wondering if somebody can help me out with a little advise on battery selection.
My first thought was to run right out to Amazon and get a couple VMAXTANKS 155's for 600 bux and free shipping.
Now, I've crapped and fell back in it a few times in my life and before doing $600 worth of that again I figured I'd ask people who actually know this stuff what they thought.

I don't plan to light up France or anything but I'd need a small heater, a few lights, a small refrigerator and a few other similar items for myself and a couple other people.
I need to steer clear of fumes so I'd need sealed units and I've seen enough bad press on gel so those are out.

Thanks for any advise,
Bill

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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
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    Re: Battery recommendations needed

    Welcome to the forum Bill.

    Gee, we've got so many bills around here it looks like Parliament (Congress)! :D

    Are you telling me NAWS sells a kit with a single 140 Watt panel and MPPT charge controller? What do they expect people to do with that? TWO 140 Watt panels, yes, but one is only going to supply about 8 Amps at best.

    Which brings us to the question of what are you going to be doing with it? Emergency back-up power is not very economical this way, and one small panel isn't going to charge much battery at all.

    Which brings up "a small heater" (epic fail; electric heaters chew up lots of power) "a small refrigerator" (we've got a whole thread about how bad they are) and "other people" (sure-fire formula for dead batteries even if they're family).

    This is another cart-before-horse case. If you could determine how many Watt hours you need to supply then it's easy to figure out how big a battery is needed and how much solar to recharge it. But maybe you don't even need the solar; the small panel could be used to maintain the battery while nothing else is happening and then when it really needs a charge you fire up the gen (if no mains power) and use a stand-alone charger.

    Definitely avoid the gels as there are very few actually suited to RE use (although arguably they're good for stand-by power). AGM's cost a bit for the stored power compared to flooded cells. Those ... well the fumes/gassing issue is sometimes exaggerated but it depends on where you have to put them.

    Don't be worried about getting a shock as all this stuff is low Voltage except on the AC side.
  • Bill Watson
    Bill Watson Registered Users Posts: 4
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    Re: Battery recommendations needed

    Ok, staying small and mobile's going to be bigger and tougher to lug around than I'd hoped.
    I'll throw some more money at it. Another panel or two, a good battery rated for what I want to do, a couple new blankets and don't throw away the cooler just yet.
    I also want this for deer/turkey hunting, fishing and camping up here in the Adirondacks and want a quiet setup that doesn't stink like gas.
    I'm trying to kill a few birds with one stone.

    Me? Government? That ain't happening.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,477 admin
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    Re: Battery recommendations needed

    More or less, 500 WH per day is good for some lighting, small radio, charging a cell phone, etc.

    1,000 WH per day--You can add a laptop computer and a small water pump for faucet/shower/etc.

    3,300 WH per day--Add a refrigerator, washing machine, well pump

    10,000 WH per day--A pretty much normal electric life (using natural gas for heating/cooking/hot water, no A/C).

    etc....

    In general, for small/seasonal systems--Look at using propane (refrigerator, heating, cooking) and/or other fuel sources to keep the electrical power usage/system size small. For 9+ month homes, an Energy Star rated full sized refrigerator is pretty nice.

    For emergency backup power, a Honda eu2000i or similar Yamaha inverter-generators are pretty nice and hard to beat.

    Get a Kill-a-Watt type meter (for 120 VAC @ 15 amp circuits) or a DC AH/WH meter for DC circuit power.

    A neat tool for use around DC power/battery banks is a DC Current Clamp DMM.

    Once you have a system--A Battery Monitor (Trimetic or Victron or similar) is pretty nice to have/understand what is going on with your system.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Bill Watson
    Bill Watson Registered Users Posts: 4
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    Re: Battery recommendations needed

    Thank you.
    These are guidelines I can use.

    Bill
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
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    Re: Battery recommendations needed

    Actually you can run the 'frige and water pump on less than 3kW hours a day (says the man who does). But yes, the little things add up fast and the big things add up even faster.

    Then there is the difference between supplying the Watt hours and supplying the Watts:
    You may run a microwave for a couple of minutes and it uses a very small amount of Watt hours (33) but in the time it is running it pulls a lot of Watts (1000). In that time it is on the inverter must be capable of the 1kW as well as supplying any other loads running at the time, and so must the batteries (1kW = 100 Amps on 12 Volt, 50 Amps on 24). These short, large loads can be the most difficult to plan for. Sometimes they aren't worth it.
  • Bill Watson
    Bill Watson Registered Users Posts: 4
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    Re: Battery recommendations needed

    Thank you. This is stuff I'll keep in mind.
    I'm just now going to order another panel, the same make/model as before.
    I've got it in mind to get a half dozen as time goes by.
    I'm ordering a battery today, too. I'll end up with a few of those in time, too.
    No point in doing stuff halfway.

    Bill