This is what I have at the moment with the hookup still on. The voltage gauge I’ve fitted onto the feed line from the LB shows 13,5v The CTEK shows fully charged and happy But the solar controller shows a half empty battery symbol as does the WiFi phone app. ?????
I had a pile of car batteries here that I’ve moved from house to house for years. Every couple of months I’d charge them. The intelligent charger would charge them up and say they were full When I put the multimeter on them they would show a decent voltage I bought one of the new intelligent battery testers and it showed most of them we’re actually knackered I’m wondering if your solar controller checks your battery in a similar way and even though it’s new it’s down on capacity
This has become a quite interesting project so first off I phoned the technical guys at Tanya batteries and asked then about this capacity reading and they (he) had no idea, and wasn’t about to go and ask anyone else there either. Then I looked into the instructions for my EPEVER MPPT controller and set the battery type on the solar controller to Gel which is what an AGM battery is classed as but as far as I can tell the only difference between Gel and Sealed as far as the controller is concerned is that it doesn’t give an equalising charge for the Gel battery. Then I read a few bits about battery health for electric cars and I “think” that the capacity reading I get on the App as a percentage is the SOC or state of charge, the opposite way of measuring this is by giving the DOD or Depth of Discharge. For SOC 100% is good, for DOD 100% is bad. Possibly this means that I could use the SOC to determine how much actual juice the battery has and when I need to turn things off. Above 12.6v should be 100% Going down to 12.06v should be 50% 11.9v = 40% 11.75v = 30% 11.58v = 20% 11.31v = 10% 10.5v = Dead as a Dodo. I think.
Bob, read this https://www.google.com/url?sa=t&sou...cQFnoECAMQBg&usg=AOvVaw01PNlcoIkSAtIoEneZikpn The pdf is really helpful by way of understanding the charge profiles the different battery types require for longevity in service. As you say, you've spent a bit so it's worth getting it right. A gel profile won't keep the AGM happy long term as it'll never fully recharge. Batteries develop 'memory' for want of a better word which means that a 90 percent charge becomes the new 'fully charged' which means next time it's less, then less again and so on. Are your starter and house batteries connected in any way, through a VSR for example?
You should be able to set a custom charge profile on the Epever, but...if the batteries are linked by a 2 way VSR then the starter battery will gas excessively on the 14.6v bulk charge the AGM needs. I had acid streaks all down the OS mudflap a few weeks ago due to precisely this. So altered the charge profile to the wet lead acid battery, and accepted that every now and then I'll have to give the AGM a belt with the Ctek, independently of the starter, to keep it happy
An AGM battery on charge and fully charged should be around 14.4 volts or even higher. It is higher than for wet batteries because there is an extra chemical reaction you are pushing which is the re-forming of hydrogen and oxygen back into water inside the pressurised cells. At that voltage the wet battery is gassing like crazy. By the way, if you look at many modern leisure batteries you will find a hole at the top at one end (sometimes with a stopper in it , should remove it anyway) into which you can push a piece of 1/4 OD plastic pipe and feed that off to outside the vehicle. Then gases and acid spray go outside down the vent pipe. When its discharging , the voltages you give above are true. This means that unless a piece of equipment "knows" that the battery is charging it has to indicate anything over 12.7 volts as 100% charged. Even though for an AGM it is not fully charged. That is up at the over 14 volt level. Comments- If you have a Voltage Sensitive Relay (VSR) in the setup that connects the two batteries at a certain voltage, and your starter battery is not an AGM battery, then you will never be able to properly charge the AGM battery as the starter battery holds the voltage down, or for that matter a Battery to Battery that decides to start feeding the starter battery when the leisure battery hits 13 volts, it will stop the leisure voltage getting high enough to charge properly. In general, the more (expensive) smart battery charging stuff you stick round batteries, the less likely it is for all the devices to achieve 100% of what their makers intended, and quite often they can be more disappointing than simpler setups as the smart stuff fights, unless it is based on a single box or a set of communicating boxes that agree e.g. "leisure battery is charging from solar" or whatever. In an ideal world, on hookup you would disconnect your batteries from the leisure load, power the leisure supply from a 12 volt power supply and leave just the leisure battery on the solar or mains charger. Then when you need it it will be at 100% rather than some lesser percentage.
it was helpful thanks and I don’t think my split charger is aVSR one unless @Dubs knows different as he fitted the latest one after I knackered the old one and I haven’t even looked at it yet. I set up my CTEK hard wired into the LB and able to use the socket to plug in the crocodile clip wire and stretch it across the engine bay to my van battery should that ever need a quick charge. And yes I do remember that, unfortunately we had to let the elephants go as we watched a very poignant advert on telly and were persuaded to adopt a Silverback Gorilla but they didn’t get on and fought constantly.
Is 14 v a typical figure for charging AND off charge and just resting or just while it is actually being charged. If it’s both what should I expect the figure to drop to two or three hours after coming off charge? my set up when plugged in to the mains is into the consumer unit then one output to a 240v house socket in the van and the second output wired into the CTEK, I figured that I wouldn’t use 12v power anywhere near as quickly as the 240v coming in could replace it and fully recharge the battery while I’m using it. The thing is now I’m doubting myself as to whether my batteries have really been ‘fully charged’ when I’ve simply checked the voltage and thought 12.7 Job done! Maybe this capacity reading would be more useful and realistic.
Well charged Lead acids including AGM drop to about 13v or so off charge, after resting. On charge AGM goes higher to 14.4v, or about 14.2v for wet cells.
