Solar generator DIY

Add these to the solar/ wind kit from Missouri wind and Power.

PowerStar 4 Pack 6V 200A Replacement for Deep Cycle Floor Scrubber Golf Cart Aerial Lift Batteries


At 29kWH per day for the house, for 3 days, I calculate 256 AH of reserve needed per day. Or 772 total ah of consumption with absolutely no recharging during that time.


Able to pretty much live indefinitely this way.

yeah, 200ah 12v LiFePO would be just as expensive if not more.

this is the killer portions of any off-grid system

 

To be fair, I'm unsure about the whole home solutions like the Delta Pro Ultra (which is brand new so I don't think I would trust it). BUT, at the same time, on the dedicated FB pages, it is the bigger stations that seem to need the most BMS/battery balancing.

I have 2 Bluetti AC180's (1152 wh) and I've only "balanced" one of them once and that was because I accidentally took it all the way to zero (zero still has a safety margin as it shuts itself off to protect itself). Since I got the first one in late June, I used it to run window fans, my clothes washer and sometimes my dishwasher or coffee pot all summer and fall. I used a portable solar panel to charge it up. I just got the 2nd AC180 in mid October as it was on a really good sale so really haven't used it but a couple of times. Haven't been able to solar charge since before Thanksgiving, so just use the house electricity.

I got the EF Delta 2 Max (2048 wh) in late July and used it mainly for kitchen appliances including the microwave (which the AC180 couldn't power). This too was charged by portable solar panels until the sun situation go too bad to be practical. This one I've had to "balance" several times.

Then there is the little Oscal Powermax 700. That one was just used to run a window fan and charge devices. I used the larger power stations to charge it. I'm not sure of the battery chemistry on this one,but it charges super slow and doesn't say anything about a discharge cycle, so may very well be lead.

The advantage of Lifpo4 is that they can be charged so much quicker than lead. The also have many more lifecycles from complete discharge to 100% charge (3,000 and up). I think they have more level power (amps or volts - I get confused) than lead, they can be stored at any angle including upside down. Some disadvantages are the maintenance compared to deep cycle marine batteries, they "brick" if left at zero for too long, they are more expensive, the operational/charging temperature range is not as wide, they need cooling and BMS which cut into the actual useful power. It is considered "good" if you can get 85% of the rated power out of a Lifepo4 - and the bigger the power pack, the more loss you have.

And now I've told you everything I know (or think I know) about that subject.

 

I wish I could harness wind. But being in a valley surrounded by houses and trees, I don't get anything consistent. It's either dead still or it is howling down the street beating up my little yard art windmill. I do keep thinking it would be great to harness the energy when that windmill is going full tilt, but it would probably only charge a phone

 

In Minnesota, I’d like to see some effective ways people have dealt with cold issues with out having a furnace built into the place.

for safety reasons, I want to have my battery shed no less than 100’ from my main structures. Doesn’t matter if it’s SLA, AGM, or lithium

 

On a couple of FB pages I've seen where people use a heating blanket that runs off DC. Or build rigid foam enclosures that will trap the heat from the battery cooling itself. It sounds like that is a balancing act as you don't want the batteries to get too warm - although in the dead of winter I'm sure that isn't a concern.

 

Just saw this on one of the FB groups.