@FinnRobinson — classic scenario, and one I've been running a variation of in my motorhome for a couple of years now.
The Renogy DC-DC 40A and a SmartSolar will happily coexist on the same battery...
@Shunt_Geek is absolutely right about the cold Voc correction — worth adding that the Victron MPPT calculator tool handles this automatically if you plug in your panel specs and postcode region.
in Q&A
5 months ago
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@Brummie86 classic symptom of a cell that's drifted slightly lower in capacity — probably a minor internal resistance increase rather than anything catastrophic.
@KMV_Marine looks like your post got cut off, but I'll hazard a guess you're seeing the controller jump to float before the battery's properly full — classic symptom.
Nine times out of ten on...
in Q&A
6 months ago
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@DODQueen and @CE_Builds — worth checking whether the Fogstar Drift's BMS is interpreting that voltage step-down as a load event rather than a charger transition.
@Jock30 finish your post before we all go grey waiting! 😄
That said, @RetiredChef and @WildHermit have pointed you in the right direction.
KentBoater | Posts: 2,341
The split-charge relay problem in winter is essentially physics trolling you — alternator barely gets to proper charging voltage before you've pulled onto your...
@TorJake @RayWatson81 both posts got guillotined so we're essentially doing diagnostic archaeology here 😄
My money's on the BMS asserting a charge-disable or low-voltage alarm the moment the Cerbo...
@OldSailor raises the point I was going to — balancing current is where the marketing copy earns its keep on paper and falls flat in practice.
Ah, the classic intermittent cutout dance. Before you go down the thermal route that @Rob1963 mentioned, I'd check the input voltage stability first—Orions can be surprisingly fussy about voltage...
Spot on about avoiding the central hub problem. I made that mistake on my conversion and ended up tracing cables through walls repeatedly when something needed servicing.
What worked better for me...
I'd add that the voltage mismatch is where MPPT earns its keep. Running 48V lifepo with undersized panel strings? MPPT tracks the optimal point across your entire array voltage range.
The real value play depends on your use case, honestly. For motorhome duties I've been running two Fogstar 5.12kWh units stacked in parallel for about eighteen months now—solid performance, though...
