I think this might work for charging the puck like @mikedjames was suggesting, small cables and 3A max (should be enough to keep the puck going) Looks like it would work to keep your starter battery topped up (instead of, not as well as the Puck).
The votronic MPP controllers can send up to 1.5A to a second battery as well Sent from my Pixel 4 using Tapatalk
Just went and checked the motorhome and battery voltage down to 8.77v with 100w solar panel attached and it parked in full sun. 20v from panel but nowt getting out the controller to the battery. Fuses in the supply and battery leads both OK so it looks like the 2 month old MPPT charge controller has died. Seller is no longer on ebay too so got no comeback.
It must have fried up over the past few weeks with all that clear sky missing contrails. But if you got the epever tracer, I would be surprised if it failed , they do have the transistors on it properly heatsinked unlike some that people have posted here where the transistors are just standing off the PCB without a heatsink.
More likely the panel has failed – they don’t like being in the sun and getting hot. Check the short circuit current from the panel before blaming the controller. Both of my 100w panels produce more than 20v open circuit but less than 1amp short circuit.
So solar panels don't like the sun? Thats clever. Its not as if its 40+ degree heat though. Maximum its been is 17C so far. Panel is a German made 100w monocrystalline one and is only 2 years old. I'm not gonna be able to get to the van until mid next week to check anything else. The battery has been on charge in my garage since about 4pm yesterday (18 hours ago) and reads 12.7v with the 3A charger still on. Not sure what it should really read.
My bus is often left out in the sun and I’m reasonably sure the panels, also 100w monocrystalline, failed due to overheating. Temperature was something I didn’t consider when I installed the solar panels but I’ve learnt a bit more since they failed and I’m serious when I said they don’t like being in the sun and getting hot – it’s the getting hot that can kill a panel. Panel efficiency, already pretty poor, will reduce with heat, they’re tested for power output at 25°C. and manufacturers rate their panels susceptibility to heat as a temperature coefficient. So, if the solar panels have a temperature coefficient of -0.45, they will lose 0.45% of their efficiency for every degree above 25°C. And panel temperature can easily be 65°C. Think about how hot a car can get sitting in the sun on a summer day - even in the UK. When, or if, I bother to replace the panels I will pay much more attention to trying to keep them cool (that might mean out of the sun) and the temperature coefficient of the panel.
Like Mr Westy I just stuck mine on (flexi) - in my case to the roof which is black vinyl covered aluminium sheet. I now realise that couldn't possibly have been worse. Mine sits in the sun 24/7/365, never shaded. It's puts out maybe a couple of volts until you flow a nice cold bucket of water over it - then it manages it's volts but still zero power. By the time I noticed the battery was kaput too. Solid have a frame that ensures an inch or so air space beneath or perhaps they wouldn't last well either.
The panel is mounted on those ABS plastic aero mounts with a 2" gap underneath. I've heard the flexy ones can fail quickly due to lack of airflow.
Mine were/are semi-flexible stuck to the roof and more prone to overheating without air circulation under the panel.
I`ve yet to fit my panel but am looking at raising it off the roof by mounting on a few lengths of 10 x 50mm plastic facia strip . Only possible issue could be wind getting undreneath when the van is dashing along at a giddy rate - i`ll cross that bridge when i get around to fitting it i.e.... when we`re all allowed to play out
Looks like there is a nice air gap. Are those holes at the end of the end of the plastic mount for air circulation?
Too hot for a solar panel is very hot. All that the "hot" does to cells in the electronics domain is reduce the efficiency by leaking current while it is hot, a solar cell is a big diode. When it cools down it recovers. But if the cells are mounted in frames made of materials that expand at different rates or the panels are fixed too firmly or with a permanent stress - fixing holes not lined up with the mounts on the roof, rigid panels bent over a curved roof and screwed down then cells made of thick silicon will crack. I still go for cracking of cells and connections and corroded connections as more likely.
My originally mega expensive panels were just glued flat on the roof or on the deck of a boat. They got hot. But they were not fixed securely, they were only really held down with 4 lines of PU so if they expanded they just lifted slightly.. They have now been peeled twice off PU glue. They still work. They have been through heat, bending and general abuse. I think the solar cells are a very thin structure fabricated direct on copper rather than very thin cells bonded to a backing.. which is the (five times) cheaper way to do it.
Above several hundred degrees C the doping atoms start moving in the silicon, then the solar cell is damaged. The heat based diode leakage is a physics effect, not chemical. Drop the temperature and the leakage stops. In different packaging in space silicon solar cells will work at over 200 degrees C. In our case the solder used in the panels will melt before the cells themselves are damaged. Basically if heat gets your solar cells its mechanical. Bad design of the panels, maybe installation. Long term its water rotting connections, cracking through flexing..
