Rory_d

I'll look Into the apps for it and see what happens with them. It's obvious now that the restart settings need adjusting as the battery isn't dropping enough to kick in the full amount of solar. At least now I know exactly what's caused it to happen! To be fair these controllers have been excellent right up until this point. The reviews I read on them seemed really good and I know people who have sworn by them so that's why I bought them. I think a bit of tweeking on settings and all will be good!!

I've ordered a Bluetooth module as apparently I can set the restart voltage through that so when that arrives I'll sort that and fingers crossed the system won't go out again like that.

Right the solar is working!! I've just measured the power coming into it and measured the power going out. Both controllers now say boost The power being generated by what's left of the sun is accurate and putting charge in!

Yes it does. I've checked it with the multimeter too and that does also!

Yes there's no voltage drop. I've charged the battery all the way to the top with the solar completely switched off. I have turned the solar back on with no load whatsoever on the battery. I have then turned the load back on and the controllers now say boost!!!! I have measured the voltage coming in from the panels and one is 40.6v and the second is 40.7v

I was literally typing that as you sent that!! It then would surely prove the point of the restart voltage!!

I've watched countless YouTube videos on this but haven't seen anything about setting that so perhaps it's gone off there! Hopefully renogy will give me an indication on how to do it otherwise the units are effectively scrap! They are most likely still under warranty so will send them back if need be and go elsewhere

There is no way that I can see anyway of manually adjusting the restart voltage on the unit. The only parameters that can be changed are the ones in the user function to allow you to put the required parameters in to match your chosen battery. This is purely because the mppts think the battery is full when it isn't. When the battery is almost dead it is at 13.2 volts. Ideally the units need to charge the battery up from 13.2 v right the way up to 14 because then the battery is 95% it's at 14.1 then 14.2 is totally full.

Would it be best to rewire the system into this controller and ditch the renogys as they are crap and what I've read online are a nightmare for lithium.

Sadly I just haven't had time this week sadly due to being chaotic at school with the kids final week and lesson planning etc! I'm going to send an email today all being well and hopefully they will teso d soon although I wouldn't expect a response now this year. It's a bit of a kick in the teeth as these units were about £100 each and now it seems this is a get what you pay for... Buy cheap buy twice situation!!

With my situation being a full time lone parent to a young lad I need as much power as I can possibly get. I've got a 12 v fridge and a 12v freezer too which I really need plus little man likes his computer games which sadly the last few months I've had to switch the freezer off and also restrict his computer time. I'll have a look at the victron kit and see if I can get perhaps one big boy that will do both panels and perhaps let me add more to meet our requirements. But that being said the 800w of solar was actually working wonders for us!

I have seen a Bluetooth dongle for renogy. I wonder if perhaps that would work with my controllers and perhaps allow any extra programming??

Also the fogstar has got a built in heater, which is one reason why I bought it. Again even when the battery temp has been good the mppts won't switch over. My understanding of fogstar battery heating is that when the temp is too low it will use the power drawn to heat the battery before accepting any charge but would create quite a draw on the solar I would imagine which theoretically would go against the problem I have here

I have actually bypassed these previously while trying to diagnose the issue when we had sunshine by the plenty! It made no difference at all! I even went outside and cleaned the panels again just to make sure it wasn't that and again made no difference. I'll get the specs off the panels and upload them here and see what the multimeter is saying