raydas
Solar Devotee
Posts: 166
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Post by raydas on Aug 17, 2019 13:12:20 GMT
I just did a check of my computer that was connected to the Load, and somehow was turned off. The computer survived, I put it on AC power and it started up like nothing ever happened.
I was running the "Solar Station Monitor" program with the save option. The last entry in the .csv file was:
The only unusual item is the array voltage(V)-17.1V. It seems like the battery array voltage was 12.6V. Now I am not sure what happened. It does not look like there was an undercurrent or overcurrent. This why I like to collect data, so when things do occur, sometimes I can derive an answer.
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Post by tattoo on Aug 17, 2019 13:20:29 GMT
sometimes I can derive an answer. The answer is don't hook anything other than a light to the load side of the CC.............
More than likely it doesn't come out well............ Not always but 90% of the time.....
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russ
Solar Advocate
Posts: 63
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Post by russ on Aug 17, 2019 19:41:21 GMT
I like to use the load output of the charge controller for powering lots of 12 volt equipment. Most equipment, such as a car stereo or a 12 volt common computer router work just fine with the charge controller output voltage fluctuation such as when the system is charging the battery and the load output voltage is over 14 volts. But for sensitive electronics you can get a inexpensive dc to dc regulator to regulate convert the voltage. To power usb devices off the charge controller load output I use a 5A adjustable voltage regulator that will convert from 12-24 volts to 5 volts. And for my notebook computers one that rated at 5 amps that converts and regulates from 12-32 volts to 12-35 volts, adjusted to 19 volts output. I find this much more efficient than using an 117 volt inverter and the notebook power supply.
Of course, a 117 volt inverter should be connected directly to the battery.
[Edit]
Also, you most definitely don't want to connect anything to the charge controller load output that has a starting surge such as a motor, or other inductive type loads. The Rover load output is rated at 20 amps. I consider this a hard limit, meaning no start surges that might exceed 20 amps.
[/Edit]
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Post by mediadogg on Aug 17, 2019 20:08:49 GMT
Good info russ, but again I question the justification for using the load output of a charge controller, unless you are depending on the timer feature. Personally, when I use the load output, it is usually only as a trigger to drive a non-inductive switch of some sort, that is controlling power. If I don't need the trigger, I just connect my loads (fused) directly to the battery, or to an inverter as needed. You can get cheap AC and DC timers if you want to prevent the loads from draining the battery during some time interval. You mentioned some cool DC-DC converters that some people might not know about. Here are some that I have used: 12V > 5V
12V to USB 3.0 and Type C (cigarette lighter adapter)
Coolgear desktop version of 12V to Type C and USB 3.0Coolgear pcb version of 12V to type C and USB 3.0Harbor Freight Solar Charge Controller - multiple DC output (there is a schematic for this on the net somewhere. Just connect across the battery and ignore the charge controller function. I plugged in one of the cigarette lighter adapters for USB 3.0 and type C, and made custom cables for the other DC outputs). Programmable USB Type C PD to specific DC out (5V, 9V, 12V, 15V, 20V) - use thse to make custom cables to power laptops, Alexa, other devices
Versatile, adjustable step down DC voltage converter
PD Buddy Sink project (actually I have not used this one yet) Using LM317t voltage regulator
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russ
Solar Advocate
Posts: 63
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Post by russ on Aug 18, 2019 7:35:01 GMT
Good info russ, but again I question the justification for using the load output of a charge controller, unless you are depending on the timer feature. Personally, when I use the load output, it is usually only as a trigger to drive a non-inductive switch of some sort, that is controlling power. If I don't need the trigger, I just connect my loads (fused) directly to the battery, or to an inverter as needed. You can get cheap AC and DC timers if you want to prevent the loads from draining the battery during some time interval. That is a good point. Unless you need the timer feature, or switching the load on at night, you may as well connect your load directly to the battery. In any case, it is not going to cause problems connecting the load directly to the battery. But, improper loads connected to the load output of the controller can cause problems, or damage to the controller.
Also, as you pointed out, fusing the loads are important. I use a 12 volt terminal strip connected to the charge controller load output that is fused at 15 amps. The charge controller load output is rated at 20 amps. And each individual load from the terminal strip is fused. Last, but not least, the wiring from the solar panels to the charge controller should be fused as well as the wiring from the charge controller to the battery. (I know you know this Mediadogg, I just think it is good to explain thoroughly.)
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Post by tattoo on Aug 18, 2019 13:07:25 GMT
But, improper loads connected to the load output of the controller can cause problems, or damage to the controller. Yes sir I agree..... Hence my post...... Why hook anything to the load side of the CC?
It is so restricted to what you can run on it why bother? That is a question?
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Post by Admin on Aug 20, 2019 23:00:20 GMT
the common error is E04 load short circuit. I person figured it out as a switch, others don't communicate or stay here long enough to decipher the issue. Can you elaborate by person figured it out as a switch? -Renogy Team
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raydas
Solar Devotee
Posts: 166
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Post by raydas on Aug 21, 2019 10:20:55 GMT
I have been using the Load, for a while now, if used correctly, it works as advertised.
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Post by bupkis on Aug 21, 2019 11:44:02 GMT
the common error is E04 load short circuit. I person figured it out as a switch, others don't communicate or stay here long enough to decipher the issue. Can you elaborate by person figured it out as a switch? -Renogy Team someone, months ago that had some sense was getting E04. I think with a max air or some type of fan (12v ceiling fan). Thru some test determined the max air switch was flaky and momentarily shorted or arced when turned on.
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Post by mediadogg on Aug 21, 2019 15:45:30 GMT
I have a question for the Renogy Team: Can the Rover 20A MPPT supply 20A to the load concurrently with charging, or is that a combined total? The legacy uses for the load terminal involved turning on lights that would burn at night from energy stored during the day, so in that scenario the load would not be powered while the controller was charging the battery. So, can the Rover supply up to 20A for charging the battery concurrently with 20A for the load, or is 20A a combined total? I also own one of these units.
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Post by Admin on Aug 21, 2019 15:58:59 GMT
I have a question for the Renogy Team: Can the Rover 20A MPPT supply 20A to the load concurrently with charging, or is that a combined total? The legacy uses for the load terminal involved turning on lights that would burn at night from energy stored during the day, so in that scenario the load would not be powered while the controller was charging the battery. So, can the Rover supply up to 20A for charging the battery concurrently with 20A for the load, or is 20A a combined total? I also own one of these units. The load controller rating (20A) indicates the max amps it should be able to supply to the battery. In the event you have a 20A load draw from the load terminal (supplied by battery), this would mean that the solar output not be charging your battery, but instead powering your load. So technically, your battery would be discharging because it is neither charging nor floating. -Renogy Team
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raydas
Solar Devotee
Posts: 166
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Post by raydas on Aug 21, 2019 16:06:45 GMT
A question for Renogy about how the float state works. Is it providing some current range at a constant rate. Or does it go into idle state, then checks to see if needs some current, then starts charging again.
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Post by tattoo on Aug 21, 2019 18:25:04 GMT
Or does it go into idle state, then checks to see if needs some current, then starts charging again. There is no idle state where the CC does no charging what so ever...... Other than at night....
Now on a Li battery you got me as I don't care for them........... I'd say no but we shall see..........
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raydas
Solar Devotee
Posts: 166
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Post by raydas on Aug 22, 2019 12:34:06 GMT
I hope Renogy can clarify a few things about the float charge activity. Below is from the Rover MPPT manual.
First thing, "...while lightly charging the battery.". What exactly is lightly charging, maybe some numbers could clarify this.
"...reduce the battery voltage to a float voltage set point.". Maybe some numbers could be beneficial.
"Once the battery is fully charged, there will be no more chemical reactions and all the charge current would turn into heat or gas.". The gas part occurs in the battery, but the heat part occurs where.
With more lithium batteries coming into the market, how is this float charge going the affect the functionality and longevity of lithium batteries. The lithium batteries have a, number of times it can be charged, associated with it, right.
I have other questions, but this in segments may be the best approach.
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Post by bupkis on Aug 22, 2019 13:04:33 GMT
different battery makers use different chemistry so the battery maker is the best source for battery charging specifics like www.trojanbattery.com/tech-support/battery-maintenance/lightly charging is enough power to maintain the float set pt voltage. It takes a certain voltage to keep the battery from self discharging and a proper float voltage does that with very little power. Float is the sweet spot between charging and self discharging, just enough. Ideally a battery could be floated indefinitely and maintain 100% of its capacity. What does the Rover manual show for float voltage for your type of battery? Happy to look it up but spoon feeding is not called for! Float voltage is different for each maker/type of battery, check the battery maker for specifics, generally low 13v to upper 13v. the heat occurs in the battery, that is where the reaction occurs, along with over gassing is bad for a battery's lifespan. While a traditional float is avoided in LI, setting a CC flot voltage low enough means it actually is not floated ie no power is needed to maintain the battery since its voltage is higher than float setting. If loads lower battery voltage low enough then the charge cycle will restart (well above float).
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