Anyone else using cheap Chinese PWM controllers or is it false economy?

Been mulling this one over myself, as I've got a small secondary panel on the shepherds hut that I was thinking of running through a cheap PWM rather than adding another Victron MPPT into the mix.

From what I've read, the main issues seem to be:

• Efficiency losses — PWM wastes more energy than MPPT, especially in cooler UK conditions where panels rarely hit their rated voltage anyway
• Longevity — some of the no-name units seem to give up after a season or two
• No proper monitoring — you're flying blind without decent data

That said, I've seen folks on here swear by the EPever Tracer range as a decent mid-ground — not rock-bottom cheap but far from Victron prices. Anyone actually stress-tested one over a full UK winter?

On my boat setup I went full Victron from the start and haven't regretted it, but that was a bigger investment where reliability really mattered. For a low-demand situation — say, keeping a leisure battery ticking over for lights and a phone charger — would a cheap PWM actually do the job well enough?

Where does the false economy line actually sit for most people? Is it panel size that's the deciding factor, or battery chemistry (presumably you'd never risk a cheap controller on lithium)?

Keen to hear from anyone who's gone budget and either regretted it or been pleasantly surprised.

@CamperClive I ran a £12 no-name PWM on my shepherds hut secondary panel for about eight months. Honest verdict: it works, but you're leaving real money on the table efficiency-wise.

PWM vs MPPT gap is most painful in low-light conditions — exactly what we get most of the year in the UK. My Victron SmartSolar was pulling usable amps on overcast mornings when the cheap controller was barely registering.

That said, if your secondary panel is genuinely small (sub-100W) and just topping up an already healthy bank, the losses become less significant. The maths changes completely.

My actual concern with the budget units is reliability and protection features — I've seen one cook a battery due to dodgy overcharge cutoff. For the shepherds hut scenario where you're not always on-site to monitor things, I'd personally spend the extra on a Victron 75/10.

@CamperClive for a secondary panel on a fixed install like a shepherd's hut I'd probably just bite the bullet and grab a Victron SmartSolar 75/10 — they're down to around £45-50 now and the Bluetooth monitoring alone is worth it for a static setup.

That said, I had a cheap PWM on my van build before I knew better. It "worked" but I was losing a meaningful chunk of output, especially on cloudy days when voltage is already marginal. MPPT earns its keep most on dull UK days, which is... basically every day here.

The maths shifts if your panel voltage closely matches your battery bank already — PWM losses are less brutal in that scenario. What panel are you adding and what voltage is it rated at?

@CamperClive slapped a cheapo PWM on the narrowboat secondary panel once — lost roughly 25% efficiency compared to my Victron MPPT and nearly cooked a battery connection because the terminals were made of what I can only describe as wishful thinking.

For a shepherd's hut that's just topping up, maybe you get away with it. For anything you actually depend on, false economy doesn't even cover it — more like false economy wrapped in false hope dipped in a fire risk.

Fogstar do decent budget gear if Victron's giving you sticker shock, worth a look before you go full Ali Express lottery.

@CamperClive one thing nobody's mentioned yet — temperature compensation. The cheap PWM units I've tried have no temp sensing whatsoever, so in winter you're undercharging your batteries and in summer potentially cooking them. On a shepherds hut that sits empty for weeks at a time, that's a real concern for battery longevity.

I ran a no-name PWM on a secondary 100W panel feeding a small LiFePO4 bank and the BMS was tripping regularly because the charge profile was all over the place. Switched to a Victron SmartSolar 75/15 — not cheap, but the Bluetooth monitoring alone is worth it for a remote install where you're not checking it daily.

If budget's tight, the Renogy Wanderer at least has some proper protections built in without breaking the bank.