Already have an Ecoflow River 2 Pro I bought a while back to power my CPAP on road trips and for emergency use, but I was thinking about something quite a bit larger to maybe power a 12 or 24V Mini Split to cool the sleeper area in the back of my tow rig on hot nights and a diesel heater for the frigid ones when I am traveling. Possibly off grid camping during out of state jibs, as well. Prices on the premade setups have come down a bunch, but issues with repair and being locked into using a manufacturer specific app to get the most out of them puts a bad taste in my mouth. Can a setup still be built cheaper than bought these days?
When you say "building your own" are you talking an already made X V battery or making the battery from cells?
Also, what kind of issues are you having with the Ecoflow that is prompting you to do more?
I've been thinking of doing one for many years, but have never pulled the trigger because batteries have never stabilized in price. Even now, you can get 100aHr LiFePO4 for under $200, when I got one at a great deal of $500 in 2021. Completed batteries are cheap enough to cover the cost of making a kit system, to me.
I'm still trying to learn and decide what to do. My target is 1200W continuous, 2400W surge, and having somewhere around +2000 Ahr in battery storage.
Yes, I have several. I've built a 24V backup for my deep freezer, several 48V golf cart batteries, and a bunch of 12V small batteries for various projects. I also have gotten tool batteries out of recycling and built my own Li-Ion E-Bike batteries.
With how cheap they are now, I would just buy a battery (note, I haven't been checking prices to see if they have spikedI).
If you want to DIY to save a few $ and know how to repair on your own I'm happy to help guide you, and recommend you check out these 2 places.
You will need a small amount of specific electrical tools to make sure you have proper top balance, and more if you want to check capacity. With your location you will need to consider how to keep them from hitting freezing temps. I would go straight to 48V for any kind of AC usage, and generally once you are past 600W sustained use go for 24V or 48V.
alfadriver said:
When you say "building your own" are you talking an already made X V battery or making the battery from cells?
Also, what kind of issues are you having with the Ecoflow that is prompting you to do more?
I would rather not make one from scratch. I'm not adverse to swapping some cells, if need be. Obviously, buying complete batteries would make the rest of the process go quicker. Setting up the whole system with wiring for 12/24V DC and 120v AC output, connection to my truck's alternator, home power, and possibly (probably?) solar to charge are my priorities, in that order. The actual wiring to my home and vehicles aren't as much of a concern, as I am not looking to do a transfer switch or anything like that at this point.
The River 2 Pro is nowhere big enough to power a Mini Split @ 768wh. I have heard of Ecoflows bricking after updates, and they aren't the most user serviceable from what I have seen so far, so that makes me queasy about a nearly $2K expenditure in a larger Delta Pro model with an advertised 3600wh.
I would like around 4,000 wh, and realize portability will have to take a hit at that size. Battery heaters and a low temp shut off are required since I travel all over the country, at most any time of the year.
In reply to californiamilleghia :
Can't hurt. Looks like some interesting options to build my own packs.
In reply to bbbbRASS :
Thank you for the forum links. I will have to root around when I get more time.
I was originally going to go with a 12V Mini Split, but then realized the gauge of cabling I would need for the draw. I then saw that there were 24v Mini Splits available, which is why I was thinking about using that voltage for the battery setup. I know there is inherent loss from an inverter, and was trying to match to the M.S. to minimize that loss to increase runtime. Of course, I haven't looked into the efficiency of DC/DC converters. 
