Jocklandjohn Posted March 21 Author Share Posted March 21 13 hours ago, simonr said: Something worth mentioning here is your Volt Meter (Multimeter). The accuracy of a mid-range meter can easily be +/-1.5%. Cheap ones, even worse. Even a high-end meter will only be +/-0.3V DC Volts just after it's been calibrated. I would never rely on it to be better than +/-1%. A mid-range meter showing 14.5V could actually be anything from 14.3V to 14.7V. (On a high end meter, 14.35V to 14.65V) Thus I shouldn't worry too much about such small apparent voltage differences. Good point. There's three separate LCD voltage displays in the van, addition to me occasionally using my handheld meter and all of them show identical readings. One is the dedicated Steca Solar data logger/control and it not only gives a real time read out but stores High/Low recordings for the previous 30 days so I can see the peaks/troughs over time and in fact have been able to relate the highs to the recent very clear sunny days we've had. This includes several days where it was logging 15.5V highs which was what had me alarmed. I can also see the days when I've disconnected the solar input and the voltages stay in the 14.3 - 14.5V range. I'm in contact with the really helpful supplier tech representative/engineer and he's talking me through various possible solutions. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted March 21 Share Posted March 21 1 hour ago, Jocklandjohn said: This includes several days where it was logging 15.5V highs Either that's a naughty controller or something else thinks it should be generating 15.5v - if it was doing this when the only power source was solar I'd suggest there's something wrong with the controller, either for real or in its measurement section. Quote Link to comment Share on other sites More sharing options...
Jocklandjohn Posted March 21 Author Share Posted March 21 5 hours ago, FridgeFreezer said: Either that's a naughty controller or something else thinks it should be generating 15.5v - if it was doing this when the only power source was solar I'd suggest there's something wrong with the controller, either for real or in its measurement section. With the technicians help I've got into the Event Log and have found a series of 15.5V highs the device recorded (but has not warned about) and one logged high voltage of 14.85 which it HAS warned about. Curiously there's a string of logged warnings of under voltage and 'Deep Discharge Protection Active'. What thats all about is anyone's guess as this is two new batteries, fully charged and showing fully charged as per alternator output and readings taken at the batteries. Tech guys are getting perplexed and suggested disconnecting everything and only connection the batteries to see if something else connected is doing odd stuff. They do note that the pulse bit of the PWM function might hit 14.9-15.5V if its compensating for cold, but that.... "Otherwise, we’ve seen it with PWM controllers that the pulses are very close together pushing battery voltage up – it’s not actually representing overcharging as such because it’s just the pulses – he can try changing frequency see if that helps." Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted March 21 Share Posted March 21 Could it be skinny wiring causing a voltage bump at the controller end when it tries to push current into the battery? As I mentioned, my eBay controllers fought each other until I ran separate wires back to the battery box so they weren't dragging each other up & down. Quote Link to comment Share on other sites More sharing options...
Jocklandjohn Posted March 21 Author Share Posted March 21 Well the wiring was all as recommended - 6mm solar cable and appropriate connectors. Might the run length be a factor? Because I have the lifting roof and the panel is at the rear end above the back door, the cable needs to run the full length of the roof (it enters at the back above the rear door) and runs all the way to the front above the windscreen and comes back to just behind the drivers seat where the controller is. so just under 4m from panel to controller. All the other wiring is either to appropriate specs or slightly over. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted March 22 Share Posted March 22 The wiring from panel to controller wouldn't shouldn't affect the battery side though, the controller is taking whatever it gets from the panel and regulating it down to charge the battery to a target voltage that it "sees" on its output terminals, what the battery actually gets is then subject to the drop on the cables from controller to battery. Quote Link to comment Share on other sites More sharing options...
Jocklandjohn Posted March 22 Author Share Posted March 22 All the cables from controller to battery are 5 or 6mm as well. I was careful in the choice to ensure it was up to appropriate spec for functionality as well as safety. I've got a few pointers from the solar tech lad who's advising from the vendor so I need to watch it for a day or so and see what additional messages get flagged when its going into over-voltage. Not had repeated 15.5V since I adjusted the charge ratio, but the occasional wanders into apparent 14.8V territory still strikes me as not normal. The numerous 'Deep Discharge Protection' alerts its logged strikes me as being really odd too and suggests something is malfunctioning. Quote Link to comment Share on other sites More sharing options...
Jocklandjohn Posted March 25 Author Share Posted March 25 Update: Over this past weekend I disconnected the relay from the Auxiliary battery so no linking function but the voltage stayed at 14.8v and later in the day the Steca data logger issued an alert message and recorded a 14.9v in brighter sun. So I thought I’d experiment. I have a spare starter battery which is exactly the same brand/capacity as the installed one in the vehicle. I completely disconnected everything from the Steca controller, the load circuits, and both batteries, but kept the solar input connected. Then using fused 6mm wire I connected the spare battery to the controller and watched the voltage in real time, measuring with my meter. It stayed at 14.45 rising to 14.5V in bright sun. I watched over a hour or so and voltage stayed steady not going above 14.5v. This seems to confirm the controller is working ok. Then I reconnected the vehicle starter battery to the Steca and I was metering 15.5V at the battery, also metering same at the controller and this reading was logged/confirmed by the Steca data logger as an over-voltage, as well being flagged as an error on my separate system monitor. This indicated a wiring issue on the vehicle side. So I completely disconnected the Steca, took it out of the vehicle and used some contact cleaner on the terminals and cable ends and then reinstalled and reconnected all the wiring. I’m always wary of over-tightening terminals in case I strip threads, but this time I tightened all the connections very tight. In full sun, readings at all points was 14.4v rising to 14.5v. All the various readouts at battery, Steca logger, separate monitor showed exactly the same voltage. I then reconnected the auxiliary battery via the split charge setup and it rose to 14.5v from its resting (disconnected) 13.8v and the whole system continued charging at 14.5v max. until the sun disappeared. This morning I started the van and ran it and voltage so far is staying steady at 14.5V. So…preliminary conclusion - it looks like it might have been a dodgy terminal connection on the solar controller. I'll see what happens one the next few days running about and in sunshine. Thanks all for your guidance and assistance! 1 Quote Link to comment Share on other sites More sharing options...
Peaklander Posted March 25 Share Posted March 25 Great to hear of your problem solving and feedback about the effect of dodgy connections! P.S. please explain more about this thing called "full sun"? 1 Quote Link to comment Share on other sites More sharing options...
Popular Post Jocklandjohn Posted March 25 Author Popular Post Share Posted March 25 (edited) 1 hour ago, Peaklander said: Great to hear of your problem solving and feedback about the effect of dodgy connections! P.S. please explain more about this thing called "full sun"? Right sit down, because this might be a long explanation. Basically every so often pagans (usually in Wales) do some weird thing or other involving 'stuff' and this sends a ripple of cosmic-ness up in to the..er...cosmos and this then stimulates a chain reaction of things, first ice-cream deliveries fail, then people in the north of England open their curtains in anticipation, the Scots actually get out of bed, and then if we're all lucky you'll notice sparkly bits outside as the rain is briefly 'sparklyfied' and then it all gets a bit dim again. If you've not experienced it yet you're in for a treat. Edited March 25 by Jocklandjohn 2 3 Quote Link to comment Share on other sites More sharing options...
Snagger Posted March 25 Share Posted March 25 😂😂😂 1 Quote Link to comment Share on other sites More sharing options...
Jocklandjohn Posted March 26 Author Share Posted March 26 Spoke too soon! Very bright sun in the middle of the day and the voltage went up to 15v. I think I'll need to reconnect the spare battery again and let it fry for a few hours and watch what happens. At least that will bypass the vehicle systems and allow me to figure out if its controller issue or a van electric gremlin. Sigh.... Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.