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Post by Paul on Oct 31, 2018 4:19:36 GMT
Hi Everyone, I'm new to solar as of about two months ago. I purchased a Renogy kit with the above components and installed them on a camper van. They seem to work great and was a breeze to install. That said, I've been noticing the voltage of the batteries will often drop overnight from 100% charge to 90-91% charge. I don't have any draws on the batteries right now and have the switch to the load function turned off. So my question is that the only load to is the controller itself and I cannot seem to find how much power it consumes.
Regardless, it couldn't be using that much power right? Its not consistently every night either, which adds to my confusion.
Any thoughts, ideas or alternative ways to monitor the consumptions more accurately to troubleshoot?
Thanks in advance!
Paul
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Post by Paul on Oct 31, 2018 4:22:34 GMT
Sorry, I thought the system details would show.
Rover 40 amp
4x100 watt panels
250 amp hour, 2 6v batteries
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Post by tattoo on Oct 31, 2018 12:08:29 GMT
That said, I've been noticing the voltage of the batteries will often drop overnight from 100% charge to 90-91% charge. Thanks in advance! Paul Hi, Glad you like your system.... What you have is very close to what I started with....
Forget about the % of the batteries on the CC it means NOTHING and it shouldn't even be there... All it does is confuse people.....
What was your voltage first thing in the morning??
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Post by playersz28 on Oct 31, 2018 12:29:39 GMT
The battery voltage will drop off after a period of time. Normally when you test them by checking voltage you let them rest for at least 8 hrs and then read the voltages. I just did my 6v AGM's and when I disconnected everything the CC was in float and they were 6.88v each with nothing connected (I disconn the connections between the 6v batteries). After 12 hrs they were at 6.45v
The SOC% is just a guess from the CC based on what it sees of the batteries but it really has no idea.
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Post by tattoo on Oct 31, 2018 12:35:44 GMT
The battery voltage will drop off after a period of time. Normally when you test them by checking voltage you let them rest for at least 8 hrs and then read the voltages. I just did my 6v AGM's and when I disconnected everything the CC was in float and they were 6.88v each with nothing connected (I disconn the connections between the 6v batteries). After 12 hrs they were at 6.45v The SOC% is just a guess from the CC based on what it sees of the batteries but it really has no idea. Yes sir, Like I said it shouldn't even be there.....
It sounds like your batteries and good and healthy...
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Post by bupkis on Oct 31, 2018 12:54:51 GMT
Hi Paul, The Battery Capacity (SOC%) is an estimation based on the charging voltage. to me 100% is defined as charging to mid 14v until the battery gets there and then holding this voltage while the current tapers (several hours). @14.6v the batts can be 80%-100% charged ! A FULL (100%) resting battery is ~12.7v (77 Fahrenheit). The controller has some algorithm based on charging voltage, so the batts got to a high voltage and reports 100%, then the surface charge is dissipated over night with no charging and the same algorithm reports way less than 100%. Both readings are likely wrong but that is the best they seem to be able to do. Read the TESTING section of trojans battery maintenance manual, a hydrometer is needed to measure the battery fluid's specific gravity. www.trojanbattery.com/tech-support/battery-maintenance/#testing Find your battery makers spec if you can! |
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Post by tattoo on Oct 31, 2018 13:49:15 GMT
Sorry, I thought the system details would show. Rover 40 amp 4x100 watt panels 250 amp hour, 2 6v batteries What is your batteries voltage checked with a Multi-meter first thing in the AM? |
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Post by Paul on Oct 31, 2018 13:52:59 GMT
Wow! Really appreciate the information and perspective. Ill hook up a volt meter for next few night/days to get a gauge on the batter levels. The batts are Full River AGMs and only about two months old. www.fullriverbattery.com/product/batteries/DC224-6 I've noticed the nights the temps drop the % drop is higher, but that sounds like its just due to the Rover's algorithm doing the best it can (although temp can sway the available voltage/capacity). So let me reiterate: If the voltage sits at 14.6v for 12 hours during the float charge (day time), it will calculate the % drop from a falsely assumed full batt voltage. When the surface charge dissipates when the float charge is stopped it records the voltage drop as % loss of capacity. Correct? From what you're all saying though, paying attention to the voltage is more important than the % on the Rover. Looking at the history of the voltage on the Renogy app, the voltage has only gotten down to 13.1v which doesn't equate to the displayed % of 90-91% capacity. Moving forward, Ill keep an eye on the voltage. Would it be wise to connect a batter monitor rather than rely on the Rover, or is that accurate enough? Next step is putting these batts to work. I really appreciate all your insight, comforting to know the system isn't already broken.  |
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Post by Paul on Oct 31, 2018 13:55:39 GMT
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Post by Paul on Oct 31, 2018 14:13:17 GMT
Sorry, I thought the system details would show. Rover 40 amp 4x100 watt panels 250 amp hour, 2 6v batteries What is your batteries voltage checked with a Multi-meter first thing in the AM? Voltage this morning was 12.9v. |
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Post by bupkis on Oct 31, 2018 14:56:44 GMT
resting 12.9 is full see link below, so if something else shows 90% ignore it or figure out how it works by monitoring it! bulk charge is getting the batts to 14.? Boost/absorption maintains 14.? float should be 13.? Those are very nice AGM batteries, a hydrometer will be useless!! FullRiver has lots of resources on their site, with a programable controller you may be able to match their charge recommendations. look at page 19 for a SoC vs voltage table, there is lots of info in that 'manual' resources.fullriverbattery.com/fullriver-battery/installation-manuals/batteries.pdf |
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Post by playersz28 on Oct 31, 2018 16:15:47 GMT
My AGM's are the Fullriver 224-6's and I have 4 of them installed. They are 3 yrs old now. They cost me ~200$US ea when I got them. I had enough old batteries kicking around to turn in for cores. FR tech said to use the SLD charge profile and set Temp comp to 4mv |
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Post by tattoo on Oct 31, 2018 16:24:22 GMT
What is your batteries voltage checked with a Multi-meter first thing in the AM? Voltage this morning was 12.9v. Man that is awesome they are fully charged.... |
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Post by Paul on Nov 1, 2018 18:53:04 GMT
resting 12.9 is full see link below, so if something else shows 90% ignore it or figure out how it works by monitoring it! bulk charge is getting the batts to 14.? Boost/absorption maintains 14.? float should be 13.? Those are very nice AGM batteries, a hydrometer will be useless!! FullRiver has lots of resources on their site, with a programable controller you may be able to match their charge recommendations. look at page 19 for a SoC vs voltage table, there is lots of info in that 'manual' resources.fullriverbattery.com/fullriver-battery/installation-manuals/batteries.pdfGood stuff Bupkis. I've never "used" them so they haven't ever bulk charged yet but the Rover limits bulk charging to 14.5v out of the box Boost - I've seen it at 14.5 on morning it says its at 90% capacity (even though its at full voltage), imited by Rover out of the box too. Float - this number hangs around 13.5-13.7 depending on the voltage coming from the panels. Ill dig into FR's resources, really appreciate the link. |
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Post by Paul on Nov 1, 2018 18:55:22 GMT
Voltage this morning was 12.9v. Man that is awesome they are fully charged.... Yes, relieved nothing strange is going on. I never realized the surface charge dies off and they rest at their regular voltage after a few hours. Thanks for your perspective it them. I just hooked up an Espar D2 to run off them so Ill finally be able to learn how to monitor them more accurately, and get a feel for their behavior. |
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