Anyone else running a cheap Chinese MPPT off a single 200W panel — what settings are you actually using?

Picked up a Renogy Wanderer knock-off (branded "SolarEpic" or something, can't even find them online anymore) for £18 off eBay about six months ago. Paired it with a battered 200W poly panel I got from a Facebook Marketplace bloke for £30, charging a 100Ah leisure battery in the van. Total outlay under £50 for the whole charging side of things, which felt like a win at the time.

Thing is, I'm not convinced I've got the settings right. The controller has a little scrolling display and a handful of programmable parameters — absorption voltage, float voltage, bulk duration, that sort of thing. I've got it set to 14.4V absorption and 13.6V float for a standard flooded lead-acid, which I think is roughly correct, but the bulk stage seems to cut out really early even on a decent sunny day. I'm only seeing maybe 40–50W input on a clear afternoon when I'd expect more like 150W+.

Has anyone else wrestled with one of these no-name units and figured out what's actually going on inside them? I'm wondering whether it's genuinely doing MPPT or just PWM with a fancy label slapped on it. Is there a simple way to test that without an oscilloscope or anything expensive? Keen to hear what settings others are running before I decide whether to bin it and save up for a proper Victron.

@VitoDream those no-name units are a lottery aren't they. I've got a similar situation in my shepherd's hut — ended up with something called "PowMr" which at least has a halfway decent manual.

For a single 200W poly panel I'd set:

• Bulk: 14.4V
• Float: 13.6V
• Low voltage disconnect: 11.8V

Sealed or AGM battery? Makes a difference. If it's a flooded lead-acid push bulk up slightly to 14.7V.

Main thing I'd watch — those cheap units often lie about their actual charging current. Worth chucking a basic clamp meter on the output occasionally just to check it's actually doing what it claims. Mine was throttling itself down silently after about 20 minutes on hot days, took me ages to figure that out. Thermal protection kicking in with zero ventilation around it.

Running almost the same setup in my shed — 200W poly into a no-name MPPT I got for about £22. Took a fair bit of fiddling but here's what's worked for me:

Bulk/Absorption at 14.4V, Float at 13.6V for my sealed lead-acid. The equalisation I've just disabled entirely — too risky with a controller I don't fully trust.

One thing worth checking @VitoDream: those cheap units often have the charge current limit set way too aggressively from the factory. Mine was throttling back at 8A when it should've been pulling closer to 11A. Had to go through a slightly baffling menu to correct it.

Also keep an eye on the temperature — mine runs noticeably warm on bright days. Stuck a small heatsink on the back with thermal paste and it made a genuine difference to efficiency.

Ran a near-identical setup in my garden office for about eight months before upgrading to a proper Victron 75/15. The one thing nobody mentions with these cheap units — check your absorption voltage carefully. Mine defaulted to 14.8V which was hammering my AGM battery. Dropped it to 14.4V and noticed a real difference in longevity.

Also worth keeping an eye on the temperature. These no-name controllers run hot in summer and the thermal throttling is basically nonexistent. I stuck mine in a ventilated enclosure after it got suspiciously warm one July afternoon.

@Chunk66 — curious what charge profile you're running. Sealed/flooded/gel setting on these often does nothing meaningful, it's just a label. Better to manually dial in the voltages if yours allows it.

Hey all, worth mentioning — on these budget units the "sealed" battery type setting often charges to 14.4V which I've found slightly aggressive for cheaper AGMs over the winter months. I dropped mine to the "gel" setting (usually 14.1V absorption) even though I'm running a standard AGM, and it's been noticeably kinder to the battery over longer float periods. Also, if yours has an adjustable low-voltage disconnect, don't trust the factory default — mine was set to cut out at 10.5V which is properly damaging territory. Bumped it up to 11.8V and haven't looked back. @Chunk66 curious whether you noticed any difference tweaking the LVD on yours?

Great thread! One thing I'd add that nobody's mentioned yet — watch your load terminals on these cheapies. I found mine was cutting load at 11.8V but the battery was actually sitting at 12.4V resting voltage due to voltage drop across a dodgy internal shunt. Stuck a multimeter on the battery terminals directly and the readings were quite different to what the controller display showed.

Worth doing a proper calibration check before you trust whatever the screen tells you. Also, if yours has a PWM/MPPT toggle buried in the settings (some do, some don't), make sure it's actually in MPPT mode — @Chunk66 might want to double-check that if you haven't already, as I've seen a few of these default back to PWM after a firmware reset. Easy win for a few extra watts from your panel.

Really useful thread this. @VitoDream one thing I'd suggest is keeping an eye on the absorption time — a lot of these budget controllers have it fixed at something daft like 3 hours regardless of battery state. If your bank is small (say 50-100Ah) that's cooking it unnecessarily. Some of the clones have a hidden "user" mode buried in the settings where you can manually tweak charge voltages; worth pressing and holding buttons in various combinations as it's rarely documented properly. I run mine in user mode set to 14.2V absorption and 13.5V float for my AGM and it's been solid. Also worth taping over the USB output if you've got one — they're notorious for drawing a small parasitic load even with nothing plugged in.