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The linear drop pattern on MPPT trackers is almost always one of two things: partial shading creating a false peak on the IV curve (tracker locks onto secondary peak), or — and this caught me out...
LH_Marine in Batteries & BMS 2 months ago
Really glad @FenlandSolar is raising this — it's something I learnt the hard way last year. To add to what @DailySolar is hinting at, even once you've confirmed you've got a BLDC motor, the...
Fiona Shaw in On a Budget 2 months ago
@SOC_Nerd and @DODGuy have covered voltage and cables, so I'll add the bit people miss — the low voltage disconnect threshold in the Phoenix settings.
@OakSoul ran a similar unit on my shepherd's hut build for about six months before swapping it out. The thing worked but I was losing a noticeable chunk of potential harvest — PWM just can't match...
Valley Tony in On a Budget 2 months ago
Yeah this trips up a lot of people. The core issue is Cerbo picks one source for SOC — it can't blend a BMS feed for cell protection logic whilst pulling SOC from a dedicated shunt like the...
CE_Builds in Batteries & BMS 2 months ago
Great thread this. Had almost the identical saga with my setup here on the farm — turned out to be a combination of things nobody had mentioned yet. Worth checking whether your cable runs are...
ExFarmer90 in DC-DC Chargers 2 months ago
@Macca spent three summers trying to sort decent panels for the narrowboat and the cabin backup array, so I feel your pain acutely. One thing nobody mentions: check the datasheet serial numbers...
Boycie25 in General Chat 2 months ago
@SolarGaz that 90% figure sounds about right from where I'm sitting. Ran a cheap Chinese hybrid inverter in the motorhome for about eight months before it developed an interesting new feature —...
Really interesting thread this — I've got a similar setup on my boat (Victron 100/30 + Fogstar 100Ah) and I've been scratching my head about exactly this issue. Quick question for the group: is...
@DaleSpirit @RetiredChef This resonates strongly with my motorhome build. What I ended up doing was running a Raspberry Pi alongside the Cerbo GX, pulling data locally via the Victron VE.Direct...
Simon Kelly in Batteries & BMS 2 months ago
@PanelKate exactly, and that's before you factor in shipping costs from Indiana plus import duty + VAT.
Marine Gaz in General Chat 2 months ago
From what I've tested on mine — the USB is always live regardless of load output state. So even when the load cuts off due to low voltage disconnect, USB stays on pulling from the battery. Caught...
@CarlWalker worth checking whether your BMV-712's Peukert exponent and charge efficiency factor are calibrated correctly for lithium — the defaults are often set for AGM and will skew SOC readings...
River Runner in Batteries & BMS 2 months ago
Same thing on my narrowboat. Ended up just leaving the Cerbo GX reading from the BMS and accepting the slightly dodgy SOC figures rather than fighting it. Would be a proper useful addition though...
Muddy Fisher in Batteries & BMS 2 months ago
Not a narrowboat person myself — I'm mostly static caravan and cabin stuff — but I've had the Victron Multiplus running in my caravan for a couple of seasons now and the remote monitoring alone...
Dale Spirit in Marine & Boat 2 months ago
@DODGuy is on the right track but I'd add — check your cable gauge and connection resistance too, not just battery voltage. I had this exact nonsense with my Phoenix 375 last winter.
SOC_Nerd in Inverters & Chargers 2 months ago
@BatteryBarry this matches almost exactly what I saw during my van build when I first wired the 75|10 into my Fogstar 100Ah LiFePO4. Worth noting — the load output does a quick voltage check...
Wild Hermit in Batteries & BMS 2 months ago
@OakSoul worth understanding why some survive and some don't — it usually comes down to how hard you're actually loading them. That 30A rating is almost certainly peak, not continuous.
Borders Explorer in On a Budget 2 months ago
Classic MultiPlus gotcha — check your transfer switch current limit in VEConfigure, but more critically, enable PowerAssist if you haven't already; it lets the MultiPlus borrow from the AC input...
Rob in Inverters & Chargers 2 months ago
@KevClark yeah that's basically giving it away isn't it 😅 Even second-hand a Multiplus-II alone goes for £600+ over here.
Panel Kate in General Chat 2 months ago