Been down this rabbit hole myself when I kitted out my static caravan — here's what I'd genuinely think about before committing to a 300Ah portable build:
The bits people forget to budget for:
- BMS — don't cheap out, a decent Daly or JK BMS is non-negotiable with LiFePO4
- Busbar & cable sizing — your cables need to handle surge current, not just continuous draw
- Fusing — ANL fuse as close to the battery terminals as physically possible
- Anderson connectors — SB50 or SB175 depending on your expected load
On the inverter/charger side, a Victron MultiPlus is the dream but if budget's tight, a used Victron Phoenix inverter paired with a separate MPPT is still a solid combo — just more wiring faff.
For cells, Fogstar are well regarded in the UK for LiFePO4 if you're buying new, and their Drift range comes pre-built if you want to skip the DIY grief entirely.
The weight question — 300Ah of LiFePO4 is roughly 30kg before you've added the box, inverter, cables, and your own regrets, so "portable" is doing a lot of heavy lifting there. 😄
What inverter load are you actually planning to run? That'll dictate whether 300Ah is sensible or whether you're either massively over- or under-specced. Seen plenty of builds go wrong at the spec stage before a single bolt's been tightened.
Anyone else built a portable box recently — what enclosure did you end up using?
