Linking batteries together in unision. Any ideas to do it safely?

[Undeadmerc3]

Hi. I just got a new hope and I'm thinking firmly about buying a backup generator. Most notibly a bluetti AC200.

However for the sake of conserving money a larger part of me is thinking about buying multiple cheaper generators at about 400 or 500 dollars a piece since I figured it would be more cost effective.

Normally I'd assume that I just hook them up with each other, but I'm starting to think it's not that simple.

Can anybody give me the details on how to pull this off withing causing any generators to fail?

 

[Al D]

I'm not sure how much you know about this solar generator. Are you looking to actually  generate power, or use already stored energy? I don't have a bluetti, and maybe someone else can chime in, but the specs look like this is a battery and inverter with the ability to be charged with external components. The actual generation of power comes from those external components. Most people want a generator for when those components are no longer available (storm, off grid, end of the world...)

If you're looking to save money, at the cost of your time and effort, you could certainly spend the $4600 on a much more capable system. It probably won't look as pretty though. To give you a broad example, you can purchase eight 280 lifepo4 cells, shipped from China, for about $900. That gives you >7kWh of battery (the bluetti model is spec'd at 5.1kWh). A $100 bms and $50-$100 for wires, terminals, and basic equipment will put you around $1100 for the total price of the battery. Then, a 3kw pure sine wave inverter, alone, will cost in the $300 -$1000 range depending on quality. The bluetti inverter is spec'd at only 2kw. So for the cost of less than half price, you could build a rough system with 50% more capability. Ensure to add on the extras as needed, but you can see it would be a huge money savings to do this yourself. It would, of course, cost you time and effort.

What smaller generators are you looking at that cost ~$500?

 

[Undeadmerc3]

I'm not sure how much you know about this solar generator. Are you looking to actually  generate power, or use already stored energy? I don't have a bluetti, and maybe someone else can chime in, but the specs look like this is a battery and inverter with the ability to be charged with external components. The actual generation of power comes from those external components. Most people want a generator for when those components are no longer available (storm, off grid, end of the world...)

Between generating power and stored energy I seem to be interested in both. I figure that rather than buy a massive generator in one swoop, buying a bunch of smaller ones would be more cost effective. What cable would you recommend that would automatically adjust from generator to generator? I know it's a weird question, but I don't want my next learning experience to involve a 500 dollar generator.

 

[Al D]

What generator are you talking about?

Wires and cables don't "adjust". You have to size your wires to handle the maximum current you will use. Current is measured in Amperes, or Amps for short. The amount of current that can safely travel through a wire, for general purposes, is determined by its thickness (gauge), metal type (usually copper, but could be aluminum - not advised), and jacket. The big box stores can accommodate wire that handles up to 260A. That's a very thick copper wire. You can't hardly bend that wire by hand. The gauge is 4/0. That's 0000 wire (verbally called "four aught wire"). It's pretty expensive and is usually special ordered.

If you're looking for a learning experience, try building a small system that could run some auxiliary devices (plug-in fans, lights, etc). Example: What solar components do you need to run an outdoor light for 8 hours at night?

 

[Undeadmerc3]

Should I start with a solar inverter and a solar panel as a jumping on point? I figure I should start slow and work my way up.

 

[Al D]

Do you know the relationship between volts ,amps, watts, joules, seconds, amp hours, and watt hours? Keep those units in mind when you learn about this stuff.

Jump on with a general layout of how a solar based system works. What components are needed in the system to make a light run at night? Draw a picture for your own edifice. It will help you greatly.

 

[Undeadmerc3]

Aside from this forum do you know of any YouTube tutorial videos on this subject I could take a look at? Should be a good start.

 

[Al D]

Youtube "DIY Solar Power". The guy who started this forum has a channel that would probably be helpful to you.