Magnum energy ms4024 love it… outback fm60 charge controller. We install magnum outback and some kisae on the entry level systems… I’ve hade a trace inverter as well. Schneiders are good but if you hit that level I prefer the outback radian series.
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Changed gears a bit, going with 48v system instead of 24v so I can use the two controllers I bought. I’m looking at some of the big inverters such as the Sigineer 12000w. Can multiple smaller inverters be used together?
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Al I was recommended the MPP Solar 60 amp charge controller by John Daniel on YouTube and I really like it. I stuck with MPP Solar when I needed a big inverter and got a PIP-5048MG. 5kW and 48 volt battery bank only. 220-240 volt AC output only. 120-450 volts PV array input. Remote generator start/grid utility backup. $800 shipped in two days from Taiwan. I like it mostly because it can handle my heavy power tools (it surges to 10kW) and it is a three-in-one inverter, charge controller, and battery charger in one for under $1000. It will accept 90-270 volts AC to charge the batteries or run loads. Plus it has a lot of features like prioritizing using PV over the utility to run loads or charge batteries, etc. I tried plugging it into my neighbour’s house and it charged my batteries at night with 120 volt “grid backup” but it has only solenoids to pass grid power through which means when the sun comes up and it switches from grid-backup mode to inverter mode the AC voltage on the output socket goes from 115 volts to 230 volts. I tell you: 230 volts will spin up my 115 volt window air conditioner real quick!
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Al: multiple small inverters together. Yes! That is another reason I went with MPP Solar PIP-5048MG: I can stack three inverters together to make 15kW of three phase power. Up to nine units will stack together to output 45kW continuous or 90kW surge power.
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I believe Shneider inverters can be stacked up to 254 together. That is some massive power.
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Thanks Brian, this gets frustrating trying to weed through all this stuff. I bought 2 midnite kid controllers, I think I can use 1 with( 3) 265w panels series 2 parallel, and the other one 2 series 2 parallel according to their on line sizing tool. I’m trying to figure what inverter(s) to use, because I may use lithium batteries, so I need one that can charge both lith.or acid batts.
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So my inverter puts out only 230 volts AC. I use a step-down transformer to run 110 volt appliances. Another thing is that my neighbor’s air conditioner went out and he said I could connect to that 230 volt circuit until next summer. In exchange, I am his emergency power source during the next outage. I would plug in and then the AC output would always be 230 volts and I could keep my batteries fully charged during the night, but I have a 4kW PV array and I only use 2500 watts overnight so my batteries only discharge 25%. So I don’t really need grid backup right now. Ask me in six months when I need electric heat in my tiny house to keep my pipes from freezing! Hopefully I will have woodgas power at that time and still won’t need grid power overnight.
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Your inverter doesn’t have two 115v legs to make the 230v?
No, mine was designed for British/European/Australian power : 220-240 volt two line only. I use a 5kW transformer for 115 volt appliances. “Offgrid Steve” on YouTube has discovered a way to combine and split the two line 230 volt AC from a PIP inverter through two transformers to create three wire split-phase 115/230 volt power.
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Today I found myself using 110 volt AC power and taking it for granted. I was just using it as I used grid power without thinking about it.
In my short 6 month experience with solar power/battery power I have seen that there are two kinds of solar PV systems in this world. The first kind are poorly designed undersized systems that underperform, require constant maintenance, and fail prematurely. Extremely expensive. Example : “Pure Living for Life” did virtually everything wrong and after two or three years they gave up on solar and went back on grid. Worst of both worlds. The second kind are well thought out, well designed, properly installed, properly maintained systems that just work, and work without thinking about it every day. Cost effective. Example: “Handeeman.” Also my system works so well I just use my power like I have so much that I would just lose it if I didn’t use it. So I leave stuff on all day because I never know when I’ll get home from work. Never had a problem. I do need a way to keep my batteries warm and vented this winter, but I also need to keep my pipes from freezing.
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9 08-18
Sounds like you are on a good path to energy independence.
As for space heating and for warming batteries, etc, I would firstly aim for increased insulation and attention to air infiltration to reduce energy losses. And for the actual heating I would aim to use biomass directly.
In theory if superinsulated, (R60), a home might need very little supplemental heating, but I think in practice for comfort in temperature fluctuations at least, a small airtight stove would fit the bill ideally.
Also nothing wrong with a dump load, but that will heat 12 hours out of sync with the greatest need, and winter solar won’t likely have excess capacity.
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How did you know I have no envelope or insulation in my house?
9 08-18
Hopefully you are joking. 
I was just speaking from a general knowledge of North American housing, and my read / approach to energy efficiency.
I feel by far the greatest energy gains are the ones you never have to expend in the first place, same applies to money self sufficiency, a topic you seem to already have a great handle on.
Thinking small and efficient will always give the greatest benefits, the targets to comfort and security are more easily reached.
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Garry, not joking. After my gasifier is finished I need to create that envelope by replacing two big doors that don’t seal and wrapping my house to create that envelope. Then finishing the ceiling and insulating. My travel trailer is sealed and insulated, though, and that is the space I condition now. I did spend the winter of 2016 in my house with a Barrel Stove. Very toasty warm near the stove, cold over near the bed. Freezing cold in the morning but I always had hot coals on the stove in the morning.
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Back to Al F’s question: What kind of inverters have you used?
Al I also would like to move toward Lithium batteries. I made sure that I could control the charging voltage on both controllers I bought so I could use them with lithium batteries. Then I bought and read the manual for my 5kW controller, and it said not to use lithium batteries, only lead batteries. I think the main difference is that lead batteries need a constant float current when full, but lithium batteries need zero current when full. Plus lithium batteries should have a brain box BMS to control cell balancing and prevent overcharging. Some say it’s optional; my controller supplier’s desire to limit liability insists on no lithium with their equipment. Maybe I will try it next year. I would just set my controller to charge lithium batteries to only 90 or 95% state of charge, and the “float” current would take 24 hours (or whatever) to overcharge, but by that time the night loads would bring the charge back down.
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I read the data sheet from Panasonic 18650 lithium cells but didn’t memorize it. It details exactly how to charge them: constant current and constant voltage and so forth. It can be done with a power supply. I would study lead acid charging algorithms versus lithium charging algorithms to make sure it was legit, but I would fear lithium charging with lead controllers.
Lithium batteries definitely need a battery management system. The cells that make up the bank will charge at different rates and lithium batteries don’t like over charging as in they will get hot and burst into flames. Over time the difference in cell charging rates will mean that while your entire pack reaches 48 VDC one row of cells can be well over the safe cell voltage while another row which charges and discharges slower will be well under voltage. With lead acid or nickel iron batteries the issue of cell balancing isn’t much of a problem the old non sealed batteries will just boil off water with the excess charge in some cells while others ballance out and you top off the water then all is well.
For the cost and longevity I would buy nickel iron before lithium unless I needed to transport the batteries like in a car or I had access to a salvage set from a Tesla or other EV. Then with salvage I would want to get the battery management system. A Tesla battery pack is actually designed to vent the flames out the sides of the car under the doors. There are videos of pack failures where flames are rolling out from both sides. Not common but it can happen. There has been alot of talk online about what will happen with insurance and lithium batteries.
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I have been looking at li-po batteries, was ready to buy until I looked more. Their life span is only 500 cycles, so I’m back to forklift battery. I found a guy in NC that rebuilds them. I’m going to see if he will sell individual 2v cells without the steel case. I read with proper care some are getting 20+ yrs. out of them.
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Frank lifespan is so dependent on depth of discharge with lead that it is very difficult to judge much by how many years people get. If someone got 20 years I would suspect they only discharged 25% of the battery pack at any one time. The issue with depth of discharge is 2 fold one it decreases lifespan faster but 2 if you only discharge the batteries 25% and they loose 50% of the original capacity you dont notice because they still have twice the capacity you are using. But if you discharge 50% and they loose 50% you are seeing them go flat. It isn’t really linear as your system cuts off at a voltage limit. But everytime I hear people talk about how long batteries have lasted in years I ask them how often they cycle them and too what level.
Anyway just my random thoughts for what it is worth. I believe lead acid is the cheapest solution at the moment. Nickel iron might be cheaper if they truly go 50 years my fear with the modern ones is the design changes make them non repairable. I mean sure you can cut the plastic case and get in there but Edison batteries where built to be taken apart cleaned and reassembled. The modern ones are spot welded and sealed in a plastic case not designed for mantaince but for easier manufacturing and lower assembly costs. There are easly 80 year old Edison batteries in use. Batteries which go all the way back to when Tomas Edison ran the factory himself. But they have been dismantled and maintained over the decades. From what I have read on the chemistry with distilled water always added to the batteries you might get 50 years changing the electrolyte every 10 years but to go much beyond 40 years you probably have to disassemble the battery and physically scrub the buildup off the plates. The modern design just doesn’t allow for that. Then I think well I am in my 40s now so in 40 years time I really won’t be the one taking them apart anyway and if I can squeak 50 years out of them I will probably not need them anymore… as I dont have kids I dont really have to worry about who I leave it to either… so I view Edison batteries as a more expensive but lifetime solution. When I look at lead acid I look at all my car batteries and think how I am lucky to get 5 to 7 years out of one. Sometimes I do better but typically 3 to 5 is all I get the winters are just hell on them up here. That is my probably irrational fear of lead acid I dont want to have the headache of installing a new pack every 5 to 10 years. But nothing lasts forever either…
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