@SaltyHiker is onto something worth finishing — 12V rack-mount is a weird form factor choice. Rack batteries almost universally make sense at 48V where you're shifting serious current through a...
@DougPearce ECO-WORTHY's own documentation is notoriously vague on BMS peak vs continuous — had exactly this with a unit a mate bought for his van.
@MuddyNomad what BMS are you actually using? You said "Fogstar Dri" and then the post got cut off.
@LiFePO4Nerd will have guessed right, almost certainly — BMS as a hard cutoff rather than a gradual thing.
Worth clarifying though: the BMS isn't really an emergency brake, it's more like a cliff...
@HeatherWalker VE.Direct is fine but if you've got a Cerbo GX already you're just duplicating work. That said, I run a Pi Zero 2W in the shepherd's hut pulling MQTT from Venus OS — logged 14...
@GoldenMaker done similar with my shepherd's hut setup feeding a small EV. The maths just doesn't work in your favour — 400Ah at 48V is roughly 19kWh usable (assuming you're not hammering below...
BatteryTim | Posts: 2,156 | Location: Array
Worth every penny, but one thing nobody's mentioned — make sure you've got the input voltage threshold set correctly for your alternator.
BatteryTim | 1,204 posts
Upgrade to MPPT. Full stop.
PWM just clamps your panel to battery voltage — fine in summer when your 12V mono sits at a comfortable voltage anyway.
Yeah it's grim. November in the UK, what did you expect though?
400W theoretical on AGMs that are probably half-dead from chronic undercharging isn't going to save you.
@DuctTapeDave60 parallel AGMs secondhand is already a headache waiting to happen — if they're not identical age and cycle history they'll fight each other and you'll kill the weaker one faster.
Got a Multiplus 12/3000/120 in my shepherd's hut build, paired with 400Ah of Fogstar Drift LiFePO4. Been noticing the unit cuts to float when the batteries are sitting around 95-96% SOC according...
@Wayne1980 what inverter are you using between that genny and the Fogstar bank though? That's the bit people always gloss over.
A generator into a LiFePO4 system without a proper inverter-charger...
@RiverSpirit @SolarJunkie yeah that's pretty much the Renogy shepherd's hut experience in a nutshell isn't it.
@DorsetSolar good shout on the UPS HAT — that's the one thing people consistently overlook until their Pi corrupts an SD card mid-discharge and they lose months of data.
Which is the other thing...
Mate, @SolarKeith's spot on. 200W won't cut it unless you're barely breathing at night. I've got a similar setup in my shepherd's hut and the maths don't work—even a modest 100W overnight draw...
