Building your own battery is kinda the point of this website (Will Prowse has a bunch of videos about doing exactly this). However, most people spending the kind of money you are talking about don't do that. Battleborne batteries are very high quality and have a 10 year warranty. If you buy them, you will not need to put any further thought into your batteries for a very long time.
If you are interested in learning the intricacies of building battery packs and find the idea of saving 40 to 50% on the batteries to be a compelling thing then don't hold back. Watch as many of Will's videos as you can first, then dive in. Understand that if you get in over your head, you can smoke a lot of expensive parts.
If you aren't looking for a new hobby or feel like it might be overwhelming, then just spending the $1800 for the Battleborne batteries and know you have the absolute very best LiFePo4 batteries you can buy. This is actually pretty unusual. Most fields it is possible for DIY to provide better quality/performance than commercial products. In the case of LiFePo4 batteries that is not true. You can save money with DIY, but they won't out perform Battleborne.
I am building my own battery pack. I am an odd ball and am building it using automotive Li-ion NMC cells (which 95% of the people on this site won't touch). I am also an EE and the primary reason I am here is this interests me and I want to learn. The NMC battery pack is an experiment and if it doesn't work out for me, then I am going to buy a pair of Battleborne batteries myself. My system is designed for 24V because that has significant advantages for use with a 2000W inverter. Pretty much everything else in my system is going to be Victron, because everything I have learned about the industry and Victron has convinced me that they design and build the very highest quality products. I appreciate that they are engineered to meet published specs and provide a very long, trouble free life. A lot of the products for sale will do neither.
I have very little confidence in the vast majority of the other inverters I have seen on the market. Basically if it costs less than $600 to $700, then run away. The difference between acceptable and best is about $400 to $500. I chose to spend the extra because I believe the quality and features of Victron make them worth it.
Samlex Evo is also a top tier inverter, but it costs pretty much the same as the Victron Multiplus. Looking at the two, I have higher confidence that the Victron will be able to deal with the peculiarities of my NMC battery pack. I also really like the Victron family of products and they play well together which is why my system will be entirely Victron: Inverter/charger, SCC, 12V/24V DC-DC Charger and point of load 24V/12V DC-DC converters.
. I haven't had any luck on craigslist really, so I think I will stick with 1-2 of the Renogy 300w 24v monocrystalline panels from home depot that were mentioned on the first page. Do you have a link to a DVM (Digital VoltMeter?) that you would recommend?
