My fumbling DIY solar generator

[Jrgunn5150]

So I'm hardly a hardcore prepper, but I do like to make thing's. The idea of free, limitless power is certainly appealing as well, not to mention, if there really was a calamity, gas isn't coming back. And a generator hammering away outback would mean I'd have to burn alot of ammo to keep my home secure.

Also, camping, I don't want to hear that crap, I want to hear nature.

I can tell you now, the cheapest course of action is to go buy a generator.

So anyway, the idea is to do something like a Kodiak 1000 that can run some lights, recharge my devices, run a fan in the camper, the water pump, and the TV and Xbox or Kindles on a rainy day. Of course they make Kodiak 1000's already, all I have to do is go buy one, but that's not who I am. It should also be fairly portable.

I started out with a Plano Sportsman box, but it's not really big enough, so I may either step down in size, or split it into two boxes as it's quite heavy now.

So what I have in here, is 4 UH-40 LifePo4 40 amp hour batteries for a total of 160ah of power at 12v, or 80ah at 24v (I've not decided voltage yet) I got them off Ebay for 55 each plus 30 shipping, but I bought 2 at a time, so he waived shipping on the second one. So 140 for 2, 280 for 4. A premade single battery would be about 1000 for a 100 AH Lifepo of name brand, and down around 600 for an off brand.

To charge the batteries I got a 40a Solar Epic charge controller. It's MPPT, so it's more efficient than the cheaper brands, and also is able to be configured specifically for the LifePo4 cells I have, that need a slightly different charge than a lead acid.

I also picked up a Newpowa 100w solar panel off Amazon, watching some reviews on Youtube, it seems to put out as much as the more expensive brands. It was 79.99

At the moment, the only inverter I have is the picture cheap little Centech 400w, which was enough to run my Xbox, Wifi, and TV, although it made a crazy sound the whole time. I'll add a larger inverter when my budget refills.

Rght here I have enough solar to run my furnace or entertainment center for a few days without input, at a total cost of 280 for batteries, 200 for the charge controller and remote monitor, 30.00 for 4 AWG wire, 20 for connectors to the solar panel, and 80 for the panel, and I'll add the inverter even though it'll be replaced later so that was like 25 bucks at a parking lot sale a few years together.

So my initial total here is 650 bucks, but it'll go up when I lock in what tote I'm using and get an upgraded inverter, also I'll probably add at least one panel to it. The most direct competitor, by the inverter I have which is 1000w peak (peak is how they rate solar generators), is the Goal Zero Yeti 1000 which is 96.8AH, and 1000w peak with no solar panel, but does have more plugs that I currently have and retails for 1100 bucks.

I'm feeling pretty good about this so far, especially now that I added it up for this thread and compared it lol.

 

[john61ct]

The best advantages of this approach are the various components fit your needs, not forced to accept a canned solution.

Easy replacement of the battery when it wears out rather than trashing the whole thing.

Choosing a known-good batt in the first place, likely to last a lot longer.

 

[Jrgunn5150]

The best advantages of this approach are the various components fit your needs, not forced to accept a canned solution.

Easy replacement of the battery when it wears out rather than trashing the whole thing.

Choosing a known-good batt in the first place, likely to last a lot longer.

Yeah, I'm certain I'm not going to get everything right, but I feel confident I can utilize the charge controller in any future iteration of this I do. Ultimately I'd like to build my own LIfePo4 pack, but that's a big chunk of change to start.

 

[workerdrone]

Console game boxes must use a ton of power - I know I measured my desktop PC at 250W or so continuous vs my laptop at 19W.

That's going to be more power hungry than almost anything but electric water heating or induction cooking or something - I mean, microwaves and blenders and such use a ton of watts but for a very short period.

 

[jonyjoe101]

I think with the 4x40ah batteries connected in series you will have 12 volts at 40ah. Thats still a decent lithium powerbank, comparable to a goalzero 400 lithium (700 dollars). All you need is a bms and some balance connectors to finish it up. I would recommend a voltage stabilizer if you plan to run 12 volt devices while charging with solar, due to possible voltage surges if the bms decides to stop the charging.

I recently built a small 27ah lithium pack (about 100 dollars in parts) and it run almost everything I throw at it including my 12 volt roadpro. Start small and build them bigger, the biggest I built was a 220ah lifepo4 (using 160x 32650 cells cost about 400 dollars) . Once you got the basics down, building them larger is no big deal.

 

[Jrgunn5150]

Console game boxes must use a ton of power - I know I measured my desktop PC at 250W or so continuous vs my laptop at 19W.

That's going to be more power hungry than almost anything but electric water heating or induction cooking or something - I mean, microwaves and
blenders and such use a ton of watts but for a very short period.

Idk, I'm probably using the killawatt wrong, but it's plugged into the wall, and the entertainment system is plugged into the powerstrip with all that stuff,a dn the Killawatt only showed .4 watts after an hour.

 

[Jrgunn5150]

I think with the 4x40ah batteries connected in series you will have 12 volts at 40ah. Thats still a decent lithium powerbank, comparable to a goalzero 400 lithium (700 dollars). All you need is a bms and some balance connectors to finish it up. I would recommend a voltage stabilizer if you plan to run 12 volt devices while charging with solar, due to possible voltage surges if the bms decides to stop the charging.

I recently built a small 27ah lithium pack (about 100 dollars in parts) and it run almost everything I throw at it including my 12 volt roadpro. Start small and build them bigger, the biggest I built was a 220ah lifepo4 (using 160x 32650 cells cost about 400 dollars) . Once you got the basics down, building them larger is no big deal.
View attachment 512867

Well, each battery is 12v and 40ah, so my understanding is if I parallel them, I'll have 160 ah. I've read that parallel so many isn't great for battery life, plus it's pretty heavy as is, so I may drop to two batteries and 80ah.

 

[workerdrone]

Idk, I'm probably using the killawatt wrong, but it's plugged into the wall, and the entertainment system is plugged into the powerstrip with all that stuff,a dn the Killawatt only showed .4 watts after an hour.

OK so that's probably .4kwh used, or 400 watts continuous. In mobile solar land, that's a bunch of power use. And your 400w inverter was maxed out and running its fan nonstop as a result. A 1000w might do the same, depends on MFR and surge/continuous design ratings.

Far more than a fridge, LED lighting, charging laptops and phones, playing a stereo...combined....as in, more usual mobile power demands in expo or RV life

Not saying don't use your console in a vehicle, just that it will necessitate a much more heavy duty system all on its own, vs using a laptop or portable gaming system to play games

 

[john61ct]

Well, each battery is 12v and 40ah, so my understanding is if I parallel them, I'll have 160 ah. I've read that parallel so many isn't great for battery life, plus it's pretty heavy as is, so I may drop to two batteries and 80ah.

Serial increase voltage, so 4S needed for nominal 12V.

Paralleling cells is OK, many as you want, will still be 3.3V only.

Yes, paralleling more than 3-4 packs or strings, like 12V batts can lead to balancing issues

 

[john61ct]

biggest I built was a 220ah lifepo4 (using 160x 32650 cells cost about 400 dollars) . Once you got the basics down, building them larger is no big deal.

Get people's hopes up

secondhand cells, likely not LFP, right?

 

[Jrgunn5150]

Serial increase voltage, so 4S needed for nominal 12V.

Paralleling cells is OK, many as you want, will still be 3.3V only.

Yes, paralleling more than 3-4 packs or strings, like 12V batts can lead to balancing issues

I would have 3s4p if I parallel them all, they are already 12v nominal, 4s packs.

Initially, I only intend to use one, but they were cheap, so I bought 4 to add on later.