He was resetting the breaker every day the GivEnergy MCB was burning out

A message came in over WhatsApp: the customer's 90-year-old father-in-law had been getting up and resetting the battery breaker every single day. The system would run for a while, the breaker would trip again, and round it went. The original installer had washed his hands of it — citing the GivEnergy administration — and left an elderly man resetting a breaker that, as it turned out, was quietly cooking itself.

What we found

This is the battery DC MCB — the isolator GivEnergy fitted to its first-generation battery systems. When we took it out, the story was written all over it. One terminal was charred black, the copper conductor oxidised green and blue from sustained heat, and the cable that had been clamped into it was scorched right through its insulation with the strands burnt back. This was not a one-off spike. It is what a connection looks like after months of running hot.

Why a connection cooks itself

The culprit here is the termination, not the battery. A screw terminal relies on a large, even contact area pressing against the conductor. The battery cable is fine-stranded copper, and when fine strands are clamped bare under a screw, they splay out — only some of them take the clamping force, and over months of heating and cooling the bundle relaxes and the clamp loosens. As the real contact area shrinks, the resistance of the joint creeps up.

And resistance under current means heat. The power dissipated in a joint is its resistance multiplied by the square of the current through it — so even a fraction of an ohm turns into watts of heat once the battery is charging or discharging hard. That heat oxidises the copper, and oxidised copper is more resistive still, so the joint gets hotter, which oxidises it further. It is a slow thermal runaway of the connection that ends exactly where the photo above ends: a charred terminal and a melted cable.

The ferrule problem — and why the ones in the box are too short

The fix for fine-stranded copper is a bootlace ferrule: a metal sleeve crimped over the strands so they become one solid pin. That gives the terminal a consistent, gas-tight contact that doesn't relax, and it is simply good practice for stranded conductors under a screw clamp. The honest truth of this trade is that ferrules are skipped more often than they should be — and an unferruled battery conductor is the single most common reason we see these MCBs burn out.

There is a GivEnergy-specific trap on top of that. The ferrules supplied in the box are a little short — short enough that the crimped pin doesn't fully fill the terminal's contact length, so part of the clamp lands on solid ferrule and part on bare or barely-crimped strands. You can do everything else right and still be left with a compromised joint. The fix is to fit longer ferrules that occupy the full depth of the terminal, crimped properly and torqued to spec. It is a small detail that decides whether the connection lasts ten years or ten months.

Why it kept tripping — the symptom that gives it away

The tell with a failing termination is that the breaker trips under load — when the battery is charging or discharging at a decent current, not when it is sitting idle. Load current flows through the bad joint, the joint heats up, and that heat soaks into the breaker's own thermal element and brings its trip point down, so it lets go well below its rated current. Reset it and the cycle simply starts again, a little worse each time. From the homeowner's chair it looks like a battery that "keeps cutting out." From the bench it is a connection getting hot enough to trip a breaker beside it — which is the same heat that chars terminals and melts insulation. (If you want the wider list of reasons one of these can trip, we keep a dedicated page on the GivEnergy battery DC MCB tripping.)

This is a fire risk, not a battery fault

It bears saying plainly: a breaker that trips daily is not a quirk to be managed by resetting it. A joint hot enough to discolour copper and melt insulation is a joint hot enough to be a fire risk, and every reset puts it back under load. If your GivEnergy battery breaker keeps tripping, the right response is to stop resetting it, switch it off if you can do so safely, and get an engineer to look at the termination — and if you can smell burning or see scorching, leave it isolated and treat it as urgent. The battery DC side is not a place for DIY; the currents are high and DC arcing does not self-extinguish the way mains does.

What we did

On site we replaced the burnt MCB, cut back the damaged cable to clean copper, and remade both terminations properly — longer ferrules filling the full terminal, crimped and torqued to specification. With the connection sound, we updated the system firmware and recalibrated the batteries so the state-of-charge and reported capacity matched reality again. The breaker stopped tripping, the system ran as it should, and an elderly man stopped having to get up and reset it every morning.

If your installer has gone quiet since GivEnergy went into administration

This job had a second, sadly familiar layer: an installer who had stepped back the moment GivEnergy's administration gave them a reason to. A failing MCB termination doesn't care who has gone out of business — and you don't have to live with a breaker you reset every day. We are independent of GivEnergy and of whoever fitted your system, and a GivEnergy battery that has been orphaned is exactly the kind of work we take on. If you're in that position, our GivEnergy in administration hub explains where owners stand, and if there's any sign of overheating our emergency repair route is the fastest way to reach us.

The takeaway

A GivEnergy battery MCB that trips repeatedly — and certainly one that has started to char — is almost never the battery's fault. It is a termination that was never made to last: a fine-stranded conductor clamped without a ferrule, or with a ferrule too short to do its job. Caught early it is a fifteen-minute fix. Left to keep tripping, it is a fire waiting to happen. If yours keeps going, don't keep resetting it — get it checked.

Field note by Ron Vitova, Solar Tech Support. Customer and original installer not named and identifying details withheld; photograph is of the actual MCB removed on the job.