The Busbar

Mandatory enforcement of RVIA's adopted standards — the 2026 edition of NFPA 1192 and the 2025 ANSI/RVIA DC Voltage Systems standard — started on 1 September, through inspections at member plants. Under Section 2-7 of the DC standard, an RV that ships with solar must have a charge controller "listed by a nationally recognized testing laboratory and rated for the array it feeds". According to RV PRO's 1 October summary, that rating means input power of at least 125% of the array maximum, and input voltage of at least the array's cold-corrected open-circuit voltage. That is the same calculation behind September's Lead, now written into a standard. Renogy showed its REGO MPPT controllers, certified to UL 1741, CSA C22.2 No. 107.1 and IEC 62109, at the Hall of Fame RV Supplier Show in Elkhart (28–30 September). Aftermarket installs are not inspected by RVIA.

Panbo's Ben Stein reported on 2 October that the Cerbo GX MK3 replaces the MK2's dual-core 1.2GHz processor with a TI Sitara AM625: four Cortex-A53 cores at 1.4GHz, built on a 16nm process, with 1GB DDR4. The supported VE.Direct device count rises from 15 to 25, and the ports are unchanged. In Victron's community forum, moderators describe the MK3 as aimed at systems with many components and heavy Node-RED use, with the MK2 still fine for ordinary installs. One user reported list pricing roughly €50–60 above the MK2. US retailers show $393 list; Victron has not published a price. The MK3 was first teased in July. When we checked, Victron's Cerbo product page did not yet mention it.

Cleversolarpower (Nick) tested 50A NH000 industrial fuses on a battery bench in a 21 September video. At 50A the fuse ran 32 minutes at about 60°C without blowing, as its time-current curve allows. At 100A the element began melting after about three minutes and dropped 2.4V across the fuse. That pulled the 12V inverter below 11V and it shut down. At 200A the same thing happened. Each time, the element had failed but the indicator wire, which needs the full current to burn through, had not. Repeated at 24V and about 93A, the inverter kept running and the striker pin popped. His conclusion: on 12V, a fuse that looks intact may not be. These fuses are rated 250V DC and built to HD 60269-2, but they are not UL-listed. The video description carries his affiliate links.

An 8-K filed on 2 October shows that Dragonfly Energy (Battle Born, and since July Dakota Lithium) signed a Limited Waiver and Eighth Amendment to its term loan on 30 September. The lenders waived testing of the minimum liquidity covenant for the month ending 30 September. They also waived any default from deferring part of the Series B preferred cash dividend due 1 October: 2% is due by 1 October and the remaining 6% by 30 October. The $450,000 amendment fee is added to principal rather than paid in cash. For context, Dragonfly reported $6.28M cash at 30 June. A covenant waiver is not a default, but a company that can comfortably meet a liquidity test does not ask to have it waived. Q3 results are the next data point.

Victron's Click & Design ESS design tool, which gained 120V and split-phase support in June, is now "available to everyone", Victron said on 28 September. The goal is to let installers share designs with customers who have no Victron Professional login. Saving a design still needs a Victron account; editing a shared link does not. Also new: French, Ukrainian and Dutch (German and Spanish "coming soon"), installer branding on PDF reports, a simulation that "accounts more precisely for the transfer and conversion losses", and separate monthly figures for priority and non-priority loads. For most of our readers the key line is the last one: "Off-grid systems with and without generators are under development." For now it remains a grid-connected tool.