A new power project

If you're after a piece of gear that is reasonably expensive, and you see a lightly fire damaged one on Ebay, keep searching. Or allow plenty of time.

We want to be more grid independent, so was looking at power wall solutions. The biggest players such as SMA and Studer not only want stupid money, but if you want to see a some pretty graphs you have to use their gear $$$$$. Enter Victron and the Multiplus II

A good range of voltages and powers. In 2022 a 3kVA/48V or 24V version can be found for 1200€. Having spent 260€, I got this

Yep, I saved ~1000€ and gained a claimed working inverter. And a fair amount of work, but that's part of the fun, right?

Before 

After

See the melted wires and connectors?

There is also a fan (blades melted) , a support PCB and trafo. The trafo just wiped clean.

Cleaning was pretty basic. A tap water rinse with plenty of directed jets. Then to displace the water 99% ethanol in a sprayer and a child's toothbrush, plus other small brushes. 

You'll read plenty on line saying soot is magnetic, but none of this soot was. The nylon bristles on the a toothbrush are ethanol safe, but the handle may melt. ESD precautions were followed; no vacuuming, and no compressed air. A wet nylon brush is OK.

 A (lithium) battery fire that caught the OSB on fire. Note the power available light.  The owner confirmed it was still working after the fire. I suspect that the wiring was too small as the 10mm battery tails were still connected. 50mm recommended.

 A load of stuff to replace, the worst of which is the main power terminals. These terminal are designed to take 70A at 230V. Imagine the size of pcb track and the amount of heat to melt the solder.

This product is repairable with large soldering irons and experience. There are 5 PCBs; a SMPS; a logic board; logic board daughter module; 2 mosfet gate drivers.

The day after cleaning, with the PCB stored at room temperature, I powered it up. It worked fine with all of the suppression caps missing and a melted fuse left it. And not earthed. 

28/2/23 Finally ordered the spares from Mouser and replaced anything dodgy. The hardest part was removing and soldering back the parts. The PCB is likely 4oz copper and whilst it has lands, it took a large soldering iron bit and a 50W iron.

The new cap at the front was slightly taller. You can't really see, but the 3 at the rear were slightly bulging. The worst had gained 1.6ohms of ESR and lost 10% capacitance. The others seemed ok. All replaced along with the 3 red ones on the PCB. 3 X caps were changed. 2 charred relays work fine. The terminals are fine, just ugly. They are around 40€ to replace with Wurth, but still 10€ from no-name. I decided that there was little point as they were not going to get out the PCB easily, and I didn't want to grind/cut them out.

The fan was replaced with a similar flow unit (Noctua NF-F12 iPPC-24V-3000 Q100 IP67 PWM), but controlled with a pic using Intel PWM commands to the fan. There are a lot of posts in the Victron community with one dealer swapping out the fan before delivery with a quieter one with half the flow. The MP commands the fan to 40% on with only 1kW load in a room at 20C. It doesn't stay on long, but I think half flow is too marginal. It's a 20mm unit vs the original 30mm. It's held on with special anti vibration mounts at the bottom and a bit of wire at the top. Moving air makes noise; there is little vibration from this fan.

21/8/2024 When I installed this hard-wired into the house wiring, I decided to limit the scope of the inverter output. The AC input, which is what ESS drives ie charge from solar, and back-feed battery to grid is connected to 1 of 4 RCDs in the main board. I jiggled a few circuits around on another RCD and this has lighting, electric gates, some kitchen sockets, some lounge sockets and some bedroom sockets. Downstream of this RCD I fitted a manual change-over between grid and the multiplus AV output. The multiplus has a built-in bypass, so during normal operation you can tell it to disconnect from the grid. However, if it fails, or you switch it off, you have no power to parts of the house. Sure you can flick the manual bypass, but you have to be there for that. So I swapped it out for an automatic transfer switch. I bought this one

Not the fastest (50ms) and an electrical life of 1500 ops. It has a warning not to connect it onto a dead short, so you need to be careful! But at 25€ it will keep the fridge running if the multiplus dies and we're away. I've got it set with the multiplus as the priority supply - no point having grid as main, then waiting 50ms for the inverter to connect when it fails!

Look carefully at the size. I got it in my board, but it's tight. 10mm2 fine strand wire helped a lot

I'm pretty sure they make these for other brands, but the CE certificate has the Geya name on.

HTU21D

The weather station is eating HTU21D humidity sensors. About 3-4 / year.

I'm beginning to think the sensors from Aliexpress aren't genuine

The temperature still works, but humidity stays at 0%

I wouldn't mind if I lived in the tropics and they were permanently wet, but the one that just failed hasn't seen proper rain for months.

Ive started covering them in PTFE tape which protected a genuine SHT for around 10 years.

Replacements

1/3/22 ? PTFE tape, otherwise open. A fair amount of verdi grée on the pins + pcb

30/10/22 sealed in acetic based clear silicone and PTFE tape

Fencing the garden

Cut the east hedge and installed 1m fence to keep the deer out. A couple of days, plus the shredding. A further afternoon for the south hedge, and 16/11 an afternoon cutting most of the north hedge.

Denver radio IR-135S

 A few internal shots. Nicely built.

The battery is a single 2000mAh 3.7V cell. 3 wires, the white marked NTC.

The USB consumption in standby/charging battery was ~0.6A. Turning the radio on increased consumption between 0.1 and 0.15A, meaning a battery life of around 9.5 hours.

Rear panel with led, usb & 2x 3.5mm jacks

30/4/24 The original 2Ah battery (from 12/2021, radio bought 8/22) is lasting less than a day. I think it used to be 4-5 days. Replaced it with 2 x 2.9Ah from BAK. 

The protection PCB from the original 1S now runs 2P. Charging current is 0.7A at 5V. Likely to be a 4-5 hour charge now. If the display is powered, it adds 0.05A. Running current adds 0.1A (TBA when charged)

Be sure to let the PCB cool down after soldering else the radio will think it's on fire from the embedded NTC (13k at 18C, W to BL)

A post I found with a good info

https://heyrick.eu/blog/entry/20230107

Dishwasher energy saving?

We basically have free hot water as surplus PV is diverted to a 65l tank. I noticed in the manual for the dishwasher that it can take cold water up to 30C. I had an old shower mixer, so I've shoe horned that into the cold and hot feeds under the sink. Early results show a 25% energy saving - the heating element is normally on 12 mins, and it's on 8 mins.

Before I start planning a cruise with the saved money, it's worth noting that it's 25% of the water heating phase. Why? Because the PV pays for the the period where the pump runs. Our modest PV will never cover the 2kW of the heater. Hover, this is the dominant cost of a dishwasher for most people. Today we are generating say 1kW. The DW heater plus other loads total around 2.1kW, so for a 12 minute period we pay for 1.1kW, or 220Wh. This happens twice for a 'run' so 440Wh. With hot water feed, the heater runs for 8 mins, so the 440W becomes 330Wh. Over a year assuming we run it every day and it's a sunny day that's 40kWh, or around 8€  saved! 

There are days when we have little or no PV, but still have hot water from the day before. In that case the savings, assuming 300W PV, on say 1.8kW are 360Wh x 2 = 720Wh * 0.25 * 365 = 66Wh / 13€

I'm not convinced the savings even paid for the PTFE tape and certainly not the 2 hours or so I spent, but it all helps. I'm still trying to find a way to offset the router which takes 20W 24/7 (35€) and push it into the daytime. It takes quite a big battery to run it from say 8pm to 8am. 

Some dishwashers, in particular Bosch and Smeg, can take cold water up to 60C which would almost double the savings.

~jan 2023. PSU failed. Threw in an old usb adapter.

12/11/23 Looks like the inlet valve is passing. Came to use the DW and found it had so much water in it, it flowed out when I opened the door. This tripped the flood alarm so I had to take it apart to dry it out. I have noticed increasingly that there is water in there and assumed that it wasnt pumping out correctly.

Lidl silvercrest induction hob SDI3500

Got a Lidl single ring induction hob.  Works well. However, about a year into the 3 year warranty it just stopped mid-use. Nothing. Rien. A fuse? Well yes, but not the obvious fuse near the inlet.

There is a thermal fuse built into a rubber piece which is in contact with the cooking top. It's easy to test. Pull the red connector and if there is no continuity, replace the thermal fuse. You can  short out the pcb connector and do a check that there is no other problem, but never run the appliance with safety items missing,

Bought a similar replacement Sefuse sk167R0. The thermal grease had all dried out and might have contributed to the over-heat triggering.

BTW the green connector is a 100k NTC thermistor.

I found this which has some photos and some other easy to fix problems.

https://academie.repaircafeparis.fr/index.php/reparer/electromenager/reparer-cuisine/44-plaques-de-cuisson/185-rca-91-une-plaque-a-induction-avec-un-fusible-thermique-defaillant

SCS1 one gate

Update 26/3/23. I won't be buying another SCS system. They are poorly designed, have no free support and have almost no adjustments. Even if support is free you can't change much. They are cheap for a reason. See the update towards the end for the latest damage caused by the system and the remedial action taken.

And now a rant about problems during an install of SCS1 one gate 27/7/22. The system it replaces has always had a dodgy motor and recently it would open and then automatically close; this is probably excessive motor current. However a new motor is around 100€ and a new system 121€. Looks like companies like to support land-fill and new sales.

I installed a 12V pro version around  9 years ago and my main complaint then is pretty much the same now. SCS buy cheap mains transformers. So cheap that the copper loss on them costs you money. Back in 2013 I reported a staggering 9W loss on a 100VA toroid.  That is truly impressive as toroids are normally very low loss. 

The trafo in the new unit is made by the world renown 'just for you enterprise' and it improves losses slightly, compared to the toroid, with only 7.5W of loss for a 80VA unit. To put this into context at 2013 prices, the waste on the original unit is 9€/year, so 81€ through life.  At 2022 prices it's closer to the price I've just paid for the replacement system (121€)

As I reported in 2013, I fitted a small mobile charger to keep the electronics working which uses 1W. This wasn't quite possible with the new system as they've installed a low voltage dropout for the battery. It's set to 24V which is way too high. You'd normally cut off at 1.75/cell = 10.5V, or 21V. However, an old 18V DC wall wart did the trick plugged into the PV connector. Once the gates try to open, a trigger on the flashing beacon turns on the original transformer. So no changes to the pcb, so warranty intact. For info the main trafo puts out 28V, giving a FWB output of nearly 40VDC. When both motors are running this drops to 32VDC.

Incidentally if you do fit a battery, just check how the charger works. I measured 40V at the battery terminals for a 24V battery (no battery), but it's fed through a FET Q6, and there is a voltage feed to the processor, so hopefully they will PWM the supply. I'm not interested in replacing lead every few years for a possible annual use, but YMMV.

Depending on whether you think it's worth the effort, some maths.  I have 3 of these poorly designed products. 2 for garage doors and 1 for gates. They would waste around 30€ of leccy per year, or 185kWh. If every home in France wastes the same, that's 3700MWh, or 1 large nuclear plant. 

The new system doesn't show gates closed, so I'm using a reed switch and a magnet to easily show this. I've also added a photocell beam which will double up as a door bell if anyone goes through the beam when the gates are open.

The beacon I have (no new one) uses a 12V bulb. I couldn't find another bulb to put in series, so robbed the 96V/76mA led panel out of an old broken light 7W and I run 4 LEDs in series off a constant current (LM317 app note) of 36mA to give a 1.2W/12W equivalent light. Must have at least 30V to light it and it takes 17mA at 34V.

The picture shows the LEDs in a SES base. It turned out the bulb holder was too tall, so I used choc block in the end, with the original diffuser balanced on top of the LEDs

The motors/arms have plastic parts, so we'll see how that works out. The motor is underneath and you can just see the metal worm drive on the left.

I didn't analyse the remotes too much, but they are Keeloq (HCS301) and use rotating codes.  SCS have helpfully changed the manufacturer's code, so any remotes from the old system (also HCS301) are now bin fodder. Really well done SCS. Nothing like re-use in your book.

Bent trafo on delivery 

The mains fuse block is incorrectly installed and badly stresses the trafo connections when the fuse is inserted/removed. Oddly, the manual has a photo of the correctly oriented installation of the holder, but the manual drawing is incorrect. Go figure.

And why do you suppose that the motors slow down at end of travel, but not when starting, so the motors, gates, mounting, etc are all given a good yank.... I knew I should have just designed my own.

My favourite fuck up by far is the wiring for the internal aerial. Whilst they have done a lovely job (really) of making a good internal one, if you replace it with an external one be really really careful. The screw terminals for the aerial are just behind a heatsink with +14V, so you have every chance of grounding the 14V rail. You will most likely destroy the regulator. Turn off at the mains and open the gates to discharge everything.

26/3/23. A sorry state of affairs. I have outward opening lightweight gates. The outward opening isn't really much different, and this will stress mounts slightly more due to the angles between the various components. However, the poor design of the product exacerbates any issues.

For example, the power supply for the 24V gate motors comes from a simple trafo that gives 32V DC when both are running, and around 36V for one. This means that the motors draw less current (whilst being damaged on over-volts) and the current sensing works less well. You have a choice of 2,3,4 or 5A. If I select 2A it's ok in the summer and wont open in the winter. Easy fixed if they bothered to install a temperature sensor. A 24V supply would help too. But even then, the current sensing is so bad at 2A that it rips the motor fixing out of a concrete pillar. The manual shows plastic rawl plugs. LOL. I used 10cm M10 rod and chemical anchors. Lasted about 2 weeks. I've used exactly the same fixings on a 1.4m satellite dish and that's not moved in some very strong wind.

I've just put a welded steel band around the pillar using 6mm plate, and it's managed to bend that.  I can just about bend this steel it in the vice. A really very poorly designed system.

I've managed to prevent this damage at fully open by moving the bracket on the gate to just beyond maximum piston extension, so the gearbox locks itself. However the shutting force is similar, so I'll have to weld some angle iron in place. I guess I'll be reporting gearbox failure in a few weeks.....

The other side is even worse. I'd put a bolt through the pillar to hold the motor bracket in place, but the continual excessive force made the bolt hole oval and a large piece of concrete has been ripped out. The control box was on this concrete but luckily I spotted it in time and thus saved replacing a 30€ plastic box (and land-filling the broken one). I'll make a similar bracket and retaining the through bolt to stop the bending.

I'm actually half hoping that I hit and damage these motors so I can justify chucking them.

The replacement from a decent company that has proper force control and/or end stops will cost 500€+  and will install in a few hours. And I'll never need to look at them again. I know this because I look after another house that has a well designed system, from a company that doesn't sell items ready for landfill. Flawless.

I really really hate shit design. It doesn't take much more effort to produce something good and long lasting. There are plenty of complaints on-line, but companies will never read posts whilst continuing to claim that they have almost no complaints. Been there, had the argument. Why would they go looking for trouble in 'unverified' posts?

The metal bending in the picture above got worse, so I ended up putting a bolt through the band. It's been 3 months and nothing has broken...