using a forklift battery

Re: using a forklift battery

BB. wrote: »

There was the Sanyo Mini-split that was a 120 VAC unit--but that just went away a few months ago when Panasonic took them over.

A few other vendors do have 120 VAC mini-splits--But not many.

-Bill

The Sanyo 120 volt unit is gone? That sucks
Re other 120 volt brands, year ago I got a Fridgaire 120 volt mini-split (heard later that many Fridigaire products were unreliable) but so far I've been VERY pleased with it. This past Summer we had the hottest weather, the whole season long, on record, and most days I ran it in AC mode all day, as long as the sun was shining. Don't know what I would have done without it. Efficiency and power consumption? Far, far better than any window AC, and by carefully adjusting the thermostat, I could control it's power draw, holding it at roughly 400 watts max, but many times it was still providing cooling with only 150 watts. That truly amazed me! Also amazing was, unlike window AC, the slow ramp-up of power consumption on startup. Very easy on the inverter. Initially, my idea was to only use it Spring and early Winter for heat when it wasn't cold enough for the wood fire and had no intention of using it as AC, but one very hot summer day, in desperation, I tried it in AC mode and nearly fell over when I realized how little power it used compared to my expectations, and that I could run it all sunny day long and still get my batteries topped up in spite of also running 2 chest freezers and an upright freezer converted to fridge! I just cannot get over what my off-grid system will handle with proper load management. Far beyond my wildest dreams! Of course it helps that initial expectations were not too high

Re: using a forklift battery

There is Good, bad and ugly...

Are you in the Ozarks? I'm in Central Missouri and bought a forklift battery last year and will be attempting what you are Setting up this fall (I should be out working now!)

Good; Your a scrounger, you've bought cheap, love the deal on the Magnum 4024! The forklift battery in a heavy use warehouse could be left with half a life if well maintained, but likely still a good deal, ask them why they are selling, if it has shown reduced life already that might be telling... Forklift batteries are normally defined by a 6 hour discharge rate. If it has 750Amps at a 6 hours discharge rate it might well have 1200 at a 20 hour rate (the rate normally used for solar aplications) There is a spec sheet Here that should offer comparisons with both rates listed.

In central Missouri I normaly have sun with heat, you may have more clouds with the Hilly area. I found that I will be close to utility costs in my rough estimates in this thread. but my utility charges $25 a month before I buy electric. Do you have 8" of insulation in the walls or is it a block wall? 6" of foam below the framing or sprayed in? ^" of foam should be @R30 but if you have wood that traversis the foam it will transmit the heat a bit. If you have it well insulated I think you'll be close. Is the cabin built in the shade or out in the open, this also will make a difference in the amount of A/C you'll need.

On the water heater, an hour to heat 19 gallons is pretty fast, 1500 watt elements are not the norm for that large a water heater, so I question if all is correct with the info. I too, will try to use an electric small water heater off solar, this is NOT recomended or natural, I'll use a timer and heat for 30 minutes at a time while the sun is shining and use a 6-10 gallon water heater. Please note that the inrush water temperature will make a difference if it's 75 in the summer and 35 in the winter the load will be greatly different, the prewarming tank will help a bunch!

The Midnite Classic Lite Charge controllers are as cheap as the 60 Amp MPPT charge controllers and have presets and can be use without special setups, we haven't discussed what type of panels you purchased but since they were cheap I would assume they are NOT 24V nominal panels. Some ignorant Solar retailers sell panels as 24 Volt that are NOT, if you wanted to use a 24V PWM charge controller you need a VMP of around 35 volts, unless they are this high they won't reach charging of equalizing voltage.

I suspect you'll want more array, but your close if your well insulated, I figured I would be close at 4 KW array, but scrounged another 2+ KW of panels on a good deal...

Re: using a forklift battery

mike90045 wrote: »

Water heating, look at the Rheem Soar Aide roof top system. Or anything but PV electric. Direct collection is several times more efficient than PV (only 14% efficient)

If you have to heat water (or air for that matter) with PV electric, look at using a heat pump instead of a resistive heater to get 3 times the heat per PV watt.

Re: using a forklift battery

ozarkgem wrote: »

my mistake. Voc is 44.5 VMPP is 36. I haven't picked up the battery yet. Have to get the dozer going to clear off a place to put everything. Are you totally off grid?

I'm totally off grid at my cabin, and at my new place, I hope to be this fall. The question about the size of the battery in 20 hour rate, Amp hours is an important one in sizing your system. Living "off grid" for me, has to do with knowing how much energy your using. Since your single some things won't be much bother at all, washing machine use is based on a family of 4 with @ a load per day. your more likely to have a load every 4 days. you'll want to 'load shift and do this sort of thing during the daytime, making it easier on your battery.

Your "normal... microwave , toaster, coffee maker and misc kitchen stuff..." will all need to be looked at as you adjust to off grid living. I don't drink coffee, but that will be a heavy load when your system is just getting going, toaster also, I regularly 'nuke' my oatmeal in the morning and that's a heavy load but for a very short time.

Other things will no longer be set and forget, I wouldn't leave the hot water heater running on thermostat, run a 'grey box' timer at least or better manually turn it on when you reach 'float' in the afternoon. A good opportunity load.

You appear to be well setup for running an A/C, the floor insulation is minimal, but 8" in the walls is great! Still I don't think I'd try to run it from the thermostat with out knowing where you stand with your battery. My cabin can likely run 24/7 on thermostat, but it is a tiny building 10x16x 14(tall) (6" walls, 8+ inches in the floor, built in the shade) with about a 1700 watt array feeding a 800Ah battery. but I don't, It's built in the shade and I set a timer to have the A/C come on and hour or so before I get home and I run the A/C window unit on economy mode. It has gas hot water and public water. The A/C and a fridge is about all it runs.

Those panels will run on a PWM charge controller for a 24V system, it won't be as efficient as a MPPT type controller and for the amount of array you have it is probably reasonable to go ahead with a MPPT type charge controller or 2. The Midnite classic lite has presets (you have to set them once with dip switches) If you want to check on your battery status you could use a trimetric meter. You can follow the link in my previous post, if you want simple and cost effective, I think that is the way to go, then again it's the way I went. If you would prefer having more information the outback charge controllers can work with their own metering system and provide a bit more info.

The Classic 150 will handle up to about 2500 watts on a 24V system. We haven't talked about the distance from your array to your battery bank. In setting up a system this is important, as you look at voltage drop over distance.

The size of your battery is important, ask the seller if the Amp hour rate is a 6 hour rate or a 20 hour rate, or ask for the type of battery, all forklift batteries I've seen have this info on the side, likely an OSHA thing. If it just has one Amp hour rating this will be a 6 hour rating and the 20 hour rate will be considerably higher. these rates have to do with the rate of discharge, if it's rated at 750 Amp hours it will take a 125 amp hour load for @6 hours, this type of battery is normally used this way. in solar applications you'll be discharging the battery much slower and it may well be closer to 1200Amp hour for 20 hours or take a 60 amp load for 20 hours. Same battery, this is the rate we 'normally' use when discussing solar battery banks. You can use the link I provided in the earlier post to compare your battery to those listed to get an idea of the true size for solar applications.

ozarkgem wrote: »

I guess the one battery is not enough?

All depends on the size of the battery...

ozarkgem wrote: »

I can always change out my WH for a gas one. I plumbed in a gas line just in case. I could get a gas refer also but I like my ice in the summer time.

If you have real data saying you can heat water it in an hour, IMO it's worth a try, again I'd have it shut off after heating and do this as an opportunity load. I think a fridge is cheaper to do off grid at this point.

ozarkgem wrote: »

If need be I can run the washing machine on the gen set. Its the AC that I will have to work on. Maybe I will just spend the summers in AK. That would be cheap!

I don't think the washing machine is a problem, I've been drying on a drying rack inside, I got use to it in the winter and at worse it takes a couple days for jeans and towels. Front load washers use the least amount of electric.

I think you'll find it rewarding to figure out the solar, I came from 'way off' the grid having started very small and growing into the larger system, not easy and I ended up with lots of spares. Coming from the grid, I suspect you'll find it challenging to live within the amount of electric you've stored.

Re: using a forklift battery

Volvo Farmer wrote: »

I'm not so sure about that. Front load washers use less water, and subsequently, less hot water. They spin more water out of the clothes, but I'm not so sure that their electricity use per load is substantially different than a top loader. The majority of the difference we see on the yellow Energy Guide labels is due to the heating of water.

I test washing machines all the time. Maybe some day I'll hook up a Kill-a-watt and measure the difference. Now I'm curious!

now that would be interesting to hear results on.