Hello there @Grandpa Gunna, although you have come late on the forum, you seem to be up with it technically with your modifications, so keep it up! Thanks for the acknowledgement about connecting Setec load through the LOAD connections on your solar controller. If you read through the posts regarding this modification, you will no doubt see how many disbelievers I had. I even had one of the "TECH HEADS" (a very knowledgeable one too) actually call at my residence whilst on holidays to satisfy himself that there was no "smoke and mirrors" with the connection. Technically, there is no way any discharge can be measured unless load is placed in series through the controller as you found out. In doing that, there are a couple of things that you need to know - mostly all for the better, but one could be a problem.
As the controller has a max charge/discharge of only 30 amps, that figure should not be exceeded. This is unlikely to occur if all the loads are through the Setec distribution system of fuse lines as the max discharge rate through the fuse is/should be 20A, even though each fuse line on my Setec ST-20 Series III has 8 fused outlets. If you were to use heavy electrical loads such as compressor or inverter, that MUST be connected directly to battery terminals by separate fused line. Never through any of the Setec outlets or the solar controller.
Now for the advantages: The Setec has a low voltage cutout which operates if battery voltage drops below 10.00 volts plus/minus 0.5 volts as shown on my diagram. IMO that is far too low and the battery would be stuffed and beyond normal recovery from that low a voltage. LVR is somewhere over 10.5 volts depending on what charging facility is used.
Now that you have the LOAD/s connected through the solar controller, you can set your OWN LVD and LOW Voltage Reconnect (LVR) to suit your use. I have mine set at 11.80 volts (LVD) and 12.20 volts for LVR. That means that if your controller, which is sensing battery voltage all the time, it will disconnect any load/s connected through the controller well before the Setec does anything!!! Anything connected directly to battery terminals as mentioned earlier will be subject to the settings on the Setec, but your solar controller would already have disconnected any loads through it. The attached chart may provide you with good guidance on SOC for your battery/ies.
You will have to find out what type of battery you have - AGM or GEL as the charging voltage is different. See also chart for this. You can then adjust your solar controller settings to the correct voltages for your type of battery. As I have an AGM 120ah, I have the max charge voltage set on my solar controller at 14.6 volts and FLOAT at 13.7 (very close to the recommended figures shown on side of battery. For a GEL battery, which will probably show 14.2 or 14.3 volts max charge and 13.8 or slightly lower for Float, all figures at 25C battery temperature. If you have a remote battery temp sensor (that should be taped to the top of battery as the controller will compensate/adjust charging voltages automatically that way. There is a temp sensor in the controller itself but that could/would be far different to the battery temps. I had to lengthen my remote lead so it was long enough to reach top of battery. You may have to do the same as it appears that your controller under the sink may be a fair distance away from battery/ies and probably in a cooler spot..
The Setec will only charge to 14.0 volts which is well below optimum voltage even for a Gel and far too low for AGMs. So check and set charge/float voltages on your solar controller as they will probably do a far better job of fully charging your battery when off grid. I use my 15A 7 stage "smart" charger at home after any time away, but especially after any time at a caravan park on 240 volts.
I hope you find the above info useful. As you can see, I believe in getting the most out of my equipment and have never been one to accept "near enough is good enough". Pedantic probably.
Please do not hesitate to contact me again as a PM or you can put it on the forum for everybody else to put in their own ideas too. .... Graham
As the controller has a max charge/discharge of only 30 amps, that figure should not be exceeded. This is unlikely to occur if all the loads are through the Setec distribution system of fuse lines as the max discharge rate through the fuse is/should be 20A, even though each fuse line on my Setec ST-20 Series III has 8 fused outlets. If you were to use heavy electrical loads such as compressor or inverter, that MUST be connected directly to battery terminals by separate fused line. Never through any of the Setec outlets or the solar controller.
Now for the advantages: The Setec has a low voltage cutout which operates if battery voltage drops below 10.00 volts plus/minus 0.5 volts as shown on my diagram. IMO that is far too low and the battery would be stuffed and beyond normal recovery from that low a voltage. LVR is somewhere over 10.5 volts depending on what charging facility is used.
Now that you have the LOAD/s connected through the solar controller, you can set your OWN LVD and LOW Voltage Reconnect (LVR) to suit your use. I have mine set at 11.80 volts (LVD) and 12.20 volts for LVR. That means that if your controller, which is sensing battery voltage all the time, it will disconnect any load/s connected through the controller well before the Setec does anything!!! Anything connected directly to battery terminals as mentioned earlier will be subject to the settings on the Setec, but your solar controller would already have disconnected any loads through it. The attached chart may provide you with good guidance on SOC for your battery/ies.
You will have to find out what type of battery you have - AGM or GEL as the charging voltage is different. See also chart for this. You can then adjust your solar controller settings to the correct voltages for your type of battery. As I have an AGM 120ah, I have the max charge voltage set on my solar controller at 14.6 volts and FLOAT at 13.7 (very close to the recommended figures shown on side of battery. For a GEL battery, which will probably show 14.2 or 14.3 volts max charge and 13.8 or slightly lower for Float, all figures at 25C battery temperature. If you have a remote battery temp sensor (that should be taped to the top of battery as the controller will compensate/adjust charging voltages automatically that way. There is a temp sensor in the controller itself but that could/would be far different to the battery temps. I had to lengthen my remote lead so it was long enough to reach top of battery. You may have to do the same as it appears that your controller under the sink may be a fair distance away from battery/ies and probably in a cooler spot..
The Setec will only charge to 14.0 volts which is well below optimum voltage even for a Gel and far too low for AGMs. So check and set charge/float voltages on your solar controller as they will probably do a far better job of fully charging your battery when off grid. I use my 15A 7 stage "smart" charger at home after any time away, but especially after any time at a caravan park on 240 volts.
I hope you find the above info useful. As you can see, I believe in getting the most out of my equipment and have never been one to accept "near enough is good enough". Pedantic probably.
Please do not hesitate to contact me again as a PM or you can put it on the forum for everybody else to put in their own ideas too. .... Graham
Last edited: