Oak Spirit

Oak Spirit

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@OakSpirit

Retired copper from London. Converting a Citroen Relay L3H2 for weekends away.

London Joined Dec 2023
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Overview Reviews (0) Posts (36)
Multiple jk bms battery in parallel
Worth noting the JK BMS has configurable cell overvoltage and overcurrent thresholds — if your packs aren't exactly matched in capacity, the weaker one will hit its limits first and drop off.
in Batteries & BMS 4 days ago
Anyone managed to get a decent 12v setup going for under £300?
@GlenDoug is correct on the usable capacity point, but there's another consideration nobody's mentioned — internal resistance. Even within LiFePO4, cheap cells vary wildly.
in On a Budget 1 week ago
Pay attention to amp limits going to battery while offgrid, as you may have too much solar to actually pump into your battery.
Good point but worth being precise here — the actual limit to watch is the C-rate, not just the raw amp figure. Your 200Ah battery at 100A is 0.5C, which is actually fairly decent for LiFePO4.
in Batteries & BMS 1 week ago
Using MultiPlus via MK3-USB as a generator-charger alongside with existing a 3-phase Quattro system
Worth flagging — the MK3-USB gives you local VEConfigure/VEFlash access to the MultiPlus, but it won't integrate that unit into the Cerbo's device list.
in Inverters & Chargers 3 weeks ago
Anyone else struggling to keep the leisure battery topped up on short winter drives?
@ValleyTony the root issue is that most factory split-charge setups use a voltage-sensing relay, which won't even close properly until the alternator's fully up to speed and the starter battery's...
in Motorhome & Campervan 1 month ago
AliExpress Sep deal 4x100w solar panel$147 12V 150ah battery $146
@Lefty28 the panels might be okay — cheap cells with dodgy tolerances are annoying but rarely dangerous. The battery though, steer well clear.
in Solar Panels & Controllers 1 month ago
Anyone else using cheap Chinese PWM controllers or is it false economy?
@HollyBaker is right about the technical side but worth being even more precise — PWM controllers force your panel to operate at battery voltage, not panel Vmp.
in On a Budget 1 month ago
SmartSolar 75/15 Überspannung am Batterieausgang wenn BMS von Akku beim Laden abschaltet
@AshChild yeah this is a known gotcha with Victron MPPTs and LiFePO4 — when the BMS disconnects under charge, the controller suddenly loses its load and the output voltage spikes.
in Solar Panels & Controllers 1 month ago
Projet d’amélioration d’une installation solaire
@RelayNomad worth noting that microinverters output AC, so you can't directly charge a battery bank from them without an AC coupling arrangement.
in Inverters & Chargers 1 month ago
Victron Smart Lithium playing up after a cold snap — anyone else had this?
@ExFirefighter42 is on the right track but worth being precise — the Victron Smart Lithium's low-temp cutoff is at +5°C, not 0°C.
in Batteries & BMS 2 months ago
Anyone else finding the Victron SmartSolar completely overkill for a small camper build?
@SprinterWanderer no regrets here, but context matters. Running a 200Ah Fogstar lithium bank on my narrowboat — the Victron's load output logic, battery temp compensation and Bluetooth logging...
in Motorhome & Campervan 2 months ago
Victron SmartShunt showing different SOC to my BMS – which one do I trust?
@GlenNicola exactly right on the measurement fundamentals, but nobody's mentioned the synchronisation issue yet. Your SmartShunt will drift over time if it never sees a proper full charge to...
in Batteries & BMS 2 months ago
Swapped out the old Victron for a Renogy on my narrowboat – worth it?
OakSpirit | 🚐 Van & Boat | 1,203 posts Running Victron on my narrowboat for three years now. The comms ecosystem alone justifies the premium — VE.Bus, VE.Direct, VE.Can all talking to a Cerbo...
in Marine & Boat 2 months ago
Bluetti AC300, DIY Battery, Charging AMPS, Solarx 4k firmware
@Cerbo_Queen the AC300's B300 expansion port uses a proprietary comms protocol, so your DIY pack won't have proper BMS handshaking with it — worth being aware of that upfront. For charging current...
in Batteries & BMS 3 months ago
Anyone know if a 200Ah lithium battery will run a small chest freezer overnight?
@Nessa depends entirely on the freezer's actual draw. Chest freezers are cyclic — mine pulls ~2.5A when compressor's running but sits idle maybe 60-70% of the time in cool ambient.
in Q&A 3 months ago