FYI I have just been doing a little research on the cheapo DIY LiFePO4 batteries.
If you want to go the cheapest for DIY LiFePO4 check out Will Prowse's channel. In the link below he tests a 280 Ah setup.
The cells are $416 (including shipping and tax) and the BMS can be anywhere from $150-$200 depending upon features.
So for LiFePO4 you are getting 0.8*280=224 Amp-Hr for $600 ish or $2.7 / amp-Hr
Compared to cheapest deep cycle lead acid 80 amp-hr / $100 which is equivalent to only $100/40 amp-hr
$2.5 / amp-hr .
Super Start Marine #24DCMJ
https://www.oreillyauto.com/detail/c...per-duty?pos=5
So capacity wise these are as cheap as lead-acid (non-AGM) but with much higher rated charge/discharge cycles. So the lifetime will be much longer. The size and increased charging rates are the know benefits as well.
I think it is recommended that you go to a 24V system if you want anything larger than this for running microwaves and induction ovens. The cable sizes just get too large.
This is somewhat older but gives a good overview.
The main thing that I did not see covered in either video is the thermal control of the battery pack. Like most things, the batteries will generally work best in temperature-controlled conditions like 20 degC. But for Lithium you have low-temperature shutoff requirements; they do not like to freeze. They can tolerate high temperatures even into the 115 degF range. See some details here.
https://batteryuniversity.com/learn/...w_temperatures
You will want to get an electric heating pad.
These are easy solutions for heating. All you need is a switch (possibly a relay but it is only 5 amps) and the thing controls itself.
Facon 7-1/4" x 25" RV Water Tank Heater Pad with Automatic Thermostat 12V DC
https://www.ebay.com/itm/30172428306...pid=1682217542
Whether you want to do any cooling will depend on battery size. Pulling 5 amps off of a 100 amp-hr battery is pushing it for an all July 4th all-day cooling scenario. In this case, I would at least run fans ( for example I am putting two 50mm/0.1 amp fans on my charge controller; two are for redundancy). For example, I have a wireless router mounted in a storage room that is exposed to the outside temperatures here in Tucson. I noticed that the heat sink was getting pretty warm and I left the case open and used a 5V USB fan to push air over the heat sink. It stays much cooler just with the forced air flow.
If you have a large battery and then a Peltier like this (4.5 A rated) might be a good idea if you can arrange a heat sink and cooling fan in the battery enclosure. So this has a comparable power diip[nation to the heater. You would need some type of thermal switch.
Teyleten Robot TEC1-12706 12V 60W Heatsink Thermoelectric Cooler Cooling Peltier Plate Module (5pcs)
https://www.amazon.com/dp/B07YZQFH65...NsaWNrPXRydWU=
This is basically how you configure a Peltier with fans to move out the heat and move the cold.
WiMas DIY Peltier Cooler Kit 12V Semiconductor Thermoelectric Cooler Peltier Cooling System TEC1-12706 Peltier Heatsink Module kit+Fan
https://www.amazon.com/dp/B07X6DX97Y...dDbGljaz10cnVl
These things are cheap and seem to work well.
2 Pieces DC 12V Electronic Temperature Controller Programmable -50 to 110 ℃ Heating/ Cooling Thermostat Control Switch Module, NTC Waterproof Sensor Probe, Dual Color LED Display Monitor
https://www.amazon.com/Electronic-Te...2059403&sr=8-5