Home Solar System

[jennyjj01]

Great warning.thanks
Makes a good case for using my 24v inverter. Instead of existing 12v
I was surprised at the fire risk just driving a 600w load

[GeraldTheBonzai]

Great warning.thanks
Makes a good case for using my 24v inverter. Instead of existing 12v
I was surprised at the fire risk just driving a 600w load

I've just spent the afternoon unbolting cables and cleaning connections. I am absolutely gobsmacked at the state of things, as in corrosion and oxidation. Granted we live on the coast, so the air is damp, but it's terrible. Just about every connection has needed to be cleaned.

The upshot is that I was using the Aferiy as a stress load. It has variable charge rates. Was charging at 600W, now charging at 900W and just about everything is ok. DC cables are around 25C after about 30 mins but stable. Got one hot spot on a breaker terminal even after cleaning - 35C. Going to take it up to 1.2Kw tomorrow and see what heats up.

Downside was that i forgot to upgrade the breaker coming out of the charge controller when I upgraded it. Have one - sitting on the shelf - just forgot. All this testing is sucking a lot out of the battery, so the CC is trying to charge it at max rate - 40A. It's a 20A breaker... Fortunately spotted it as I was watching everything (and the sun went in)

Have to admit, I've learned a lot with all this tinkering, but am starting to get a bit tired off it. Can see the attraction of just buying an off the shelf "kit" and forgetting about the rest of it.

[GeraldTheBonzai]

Interesting..

Vertical bifacial PV outperforms tilted PV systems in the UK

https://www.pv-magazine.com/2026/04/15/ ... in-the-uk/

[jennyjj01]

Interesting..

Vertical bifacial PV outperforms tilted PV systems in the UK

https://www.pv-magazine.com/2026/04/15/ ... in-the-uk/

Indeed.
Bifacial panels give you collected energy on the back 'for free' E.g a 500W bifacial panel with a mirror could generate way more than 500W It's effectively two panels that are forced to look in opposite directions.
It all makes orientation quite complex when accounting for usage patterns and seasonality.
Add in mirrors or reflective paint/gravel and the bonus could be massive.

I notice that the panels in that study were long and narrow and would serve as reflectors onto eachother.
Also, to be cynical, the study and article are something of an advertorial.

[GeraldTheBonzai]

So, I have been stress testing my home solar power rig, following the heat issues due to corroded connectors. Now that everything has been cleaned up etc, am getting much better thermal control. However still have a few bits to solve. To recap, when running it at a 600W load at 12V, I was getting a couple of hot cables (one in particular).

This is the actual rig. Renogy 2Kw inverter, Eco-Worthy 280Ah battery, Renogy Rover 40 Charge controller.

This is the thermal image with no load. Temperature in the is around 19C, as its south facing. The max is coming off off the concrete floor outside.

HM20260417154330.jpeg (84.29 KiB) Viewed 66 times

I than ran it at 600W load at 20 minutes. The 29.8C Max is the cable coming out of the break, on the +ve DC, going into the inverter. However, it is in the sun. But..

HM20260417155811.jpeg (88.27 KiB) Viewed 66 times

I then cranked the load up to 1.2Kw and left it for 15 minutes. The first image is the fuse on the -ve return to the battery. Bit warm, but was stable. The next two are the 150A breaker again. Getting a bit toasty. Ok to touch but definately a bit on the warn side.

HM20260417160130.jpeg (88.34 KiB) Viewed 66 times

HM20260417161256.jpeg (86.93 KiB) Viewed 66 times

HM20260417160057.jpeg (87.46 KiB) Viewed 66 times

So the issue now is that breaker. Reason its causing a problem is that it was cheap, so has stupid little terminal connectors. Need to swap that out for something with a recent surface area - at least M8. The lugs on the cable onto it are M8 and there is slack. However, from a supply perspective, my base load is around 200W. Running it at 600W then I'm now fine. Can even crank it up to 6X my need, and with a few tweaks, should be fine. .

[Peter]

I’ve found a smear or copperslip grease on high current connectors (ie vehicle engine earth straps) improves
connection and prevents corrosion, and could be beneficial but I haven’t tried it on our solar rig.

[jennyjj01]

Do you guys think that adding in whopping great fuses might actually increase fire risk because of the extra terminals in play?
I'm starting to feel uneasy about some of the very high currents involved with these leisure batteries and inverters. I worry less about the mains voltage side.

[Yorkshire Andy]

Do you guys think that adding in whopping great fuses might actually increase fire risk because of the extra terminals in play?
I'm starting to feel uneasy about some of the very high currents involved with these leisure batteries and inverters. I worry less about the mains voltage side.

Id initially fuse the battery

If it's a single battery
https://ebay.us/m/WfW4Ob
Something like this with the appropriate fuse /s

[GeraldTheBonzai]

A fuse will protected you from a catastrophic short, but running at 12V means you by necessity run at high current. My issues are thermal. For instance I use 35mm welding cable for my battery runs, which is rated at 240A. However, that's a max current. For prolonged use, ideally it needs to be a lot less than that, but a 2Kw inverter flat out is pulling around 180A. So at that level, I ought to use 50mm or 70mm cable. That size cable is hard to crimp yourself, plus it needs big terminals to attach to.

Or you go up in voltage. Like most people I started off with a small inverter and a 12V leisure battery. That's fine for a camper van or shed where you are maybe pulling 200w. But now I've got to the stage where I want a more extended capability.

With hindsight, I should have started at 24V or more. But now you are into kit that is much more expensive (victron etc). I could take the rig to 24V, but then i'd need a second battery, a balancer and a new inverter. Or go for one of these combined hybrid charger/inverter solutions. Either way, it's more expenditure.

On the other hand, the Aferiy I bought runs on 40135 lithium cells. Internally, the pack is at 51.2V so flat out at 2.8Kw it's only doing 55A ish. At my base load, it's about 6 A..

[Yorkshire Andy]

A fuse will protected you from a catastrophic short, but running at 12V means you by necessity run at high current. My issues are thermal. For instance I use 35mm welding cable for my battery runs, which is rated at 240A. However, that's a max current. For prolonged use, ideally it needs to be a lot less than that, but a 2Kw inverter flat out is pulling around 180A. So at that level, I ought to use 50mm or 70mm cable. That size cable is hard to crimp yourself, plus it needs big terminals to attach to.

Or you go up in voltage. Like most people I started off with a small inverter and a 12V leisure battery. That's fine for a camper van or shed where you are maybe pulling 200w. But now I've got to the stage where I want a more extended capability.

With hindsight, I should have started at 24V or more. But now you are into kit that is much more expensive (victron etc). I could take the rig to 24V, but then i'd need a second battery, a balancer and a new inverter. Or go for one of these combined hybrid charger/inverter solutions. Either way, it's more expenditure.

On the other hand, the Aferiy I bought runs on 40135 lithium cells. Internally, the pack is at 51.2V so flat out at 2.8Kw it's only doing 55A ish. At my base load, it's about 6 A..

That's the issue despite the price of the power banks / stations they are "tested" and we assume safe

My mate who volunteers for a big nation wide youth group shall we say got an telling off by tptb at a big camp for daring to put a leisure battery and inverter under his desk by his tent... Elf and safety dangerous battery etc something metallic might land on the terminals and cause the battery to explode yada yada well inverter was powering the groups laptop which was as good as flat.. to save a ruckus he put it all away ...

3am little Jonny pukes up in his tent .. he gets a rattle on his tent by one of the head honchos (this group doesn't allow paperwork on camps as it's not "secure" unlike a laptop with passwords etc obviously by now the laptop is dead)

he gets out his doss bag gets the laptop "you want to phone Jonny's mum to collect him.. you best find a way to charge this up "

And gets back in his bed

Oh and he's a fully ticketed electrical engineer so Id hope knows far more than a my book says head honcho