Epever 6415AN doesn't respect my settings

[RStone13]

looking good today. Boosted all morning, dropped into float right as the cells were close to max. Floating a little lower than expected, but between float and boost recon so within tolerance.

I saw my first boost, float, boost recon, float cycle today. It functioned correctly. The voltages tolerances were a bit wider than expected, but totally within comfort. I'm going to call this configuration successful. I will let it run as is for one more day, just to confirm everything, then back it down to the voltages i want long-term. Likely around 2.5v lower as it feels way high for my comfort. Still within acceptable, but why charge to 100% if you don't have to?

Great, glad you resolved the issue. On to the next problem

 

[fafrd]

looking good today. Boosted all morning, dropped into float right as the cells were close to max. Floating a little lower than expected, but between float and boost recon so within tolerance.

I saw my first boost, float, boost recon, float cycle today. It functioned correctly. The voltages tolerances were a bit wider than expected, but totally within comfort. I'm going to call this configuration successful. I will let it run as is for one more day, just to confirm everything, then back it down to the voltages i want long-term. Likely around 2.5v lower as it feels way high for my comfort. Still within acceptable, but why charge to 100% if you don't have to?

Cool. I’m not going to be interested in Epever until you are 100% happy with them.

Can you provide some idea of the currents involved (charge current out of the Epever and Load Current into the Inverter when the charger went from Float to Boost Reconnect?

I’m also interested in how long the charger remained in Float and what level of peak current it supplied to Load Current before either Inverter reduced draw of the voltage dropped to Boost Reconnect?

I’m interested to understand what level of current you are seeing your Epever SCC supply to load/Inverter while still retaining battery at Float Voltage...

 

[jnrhome]

I had a hot, sunny morning and into mid-afternoon. I boost charged at 45-50 amps from 11a to about 2P, then switched to float. Around 2:30p, some clouds rolled through, creating a variable input while in float. It took about 20 minutes of high variability to hit boost recon. Once in boost, it only took about 15 minutes to get back to float. This happened a second time from passing clouds, as opposed to heavier variable load. When the suns is constant, I can't load it enough to drop back into boost. The float rises to meet any load I demand.

The controller dropped into float slightly below the set boost voltage and ran in float with a fair variability, mostly between boost and boost recon voltages, never above boost, but sometimes below boost recon. I may tighten the boost to boost recon voltage a bit and see if that gets less variable. The boost recon kicked in after the system spent 5-10 minutes below the set boost recon voltage so not as quickly as i expected, but tolerable.

My load is approximately 16KW/day, split into two pieces, constant (about 13KW) and intermittent (about 3KW). The constant load runs about 550 watts, 24 hours a day. The surge is from the refrigerator which uses about 1,100 watts to start, then runs about 120 watts. The coffee pot uses about 1,000 watts and cycles around 50% while in use. I have two 24v inverters, one 500w and one 1,500w. The 500w runs my WISP equipment, LED light strings in the whole house and a box fan. The 1,500w runs my kitchen and my main working desk system (4 laptops, 4 32" monitors, 6 iphones, two raspberry pi's and two usb desk fans) and another box fan. I am using my old sealed lead acid cells as 24v buffers for the inverters. The 500w has 24v, 150a lead acid battery bank and the 1500w inverter has 24v, 220a lead acid battery bank directly attached. I use a 48v-24v buck converter to supply a steady charge to the subsystem, set to a couple amps above the constant load. All the surge loads draw down the lead acid, while the constant loads are fed from the main bank. When a surge draws down the subsystem, the charge from the main system rises to restore it to a preset voltage. This works FANTASTIC, allowing me to surge the 24v inverters to max+ load without passing the surge to the main bank. The limiting in the buck converter allows me to have a max draw on the circuit until the 24v battery gets back to optimal voltage, then taper back to the constant load.

I have a 48v, 3,000w inverter coming Monday so that will require a re-think on the design.

 

[fafrd]

I had a hot, sunny morning and into mid-afternoon. I boost charged at 45-50 amps from 11a to about 2P, then switched to float. Around 2:30p, some clouds rolled through, creating a variable input while in float. It took about 20 minutes of high variability to hit boost recon. Once in boost, it only took about 15 minutes to get back to float. This happened a second time from passing clouds, as opposed to heavier variable load. When the suns is constant, I can't load it enough to drop back into boost. The float rises to meet any load I demand.

The controller dropped into float slightly below the set boost voltage and ran in float with a fair variability, mostly between boost and boost recon voltages, never above boost, but sometimes below boost recon. I may tighten the boost to boost recon voltage a bit and see if that gets less variable. The boost recon kicked in after the system spent 5-10 minutes below the set boost recon voltage so not as quickly as i expected, but tolerable.

My load is approximately 16KW/day, split into two pieces, constant (about 13KW) and intermittent (about 3KW). The constant load runs about 550 watts, 24 hours a day. The surge is from the refrigerator which uses about 1,100 watts to start, then runs about 120 watts. The coffee pot uses about 1,000 watts and cycles around 50% while in use. I have two 24v inverters, one 500w and one 1,500w. The 500w runs my WISP equipment, LED light strings in the whole house and a box fan. The 1,500w runs my kitchen and my main working desk system (4 laptops, 4 32" monitors, 6 iphones, two raspberry pi's and two usb desk fans) and another box fan. I am using my old sealed lead acid cells as 24v buffers for the inverters. The 500w has 24v, 150a lead acid battery bank and the 1500w inverter has 24v, 220a lead acid battery bank directly attached. I use a 48v-24v buck converter to supply a steady charge to the subsystem, set to a couple amps above the constant load. All the surge loads draw down the lead acid, while the constant loads are fed from the main bank. When a surge draws down the subsystem, the charge from the main system rises to restore it to a preset voltage. This works FANTASTIC, allowing me to surge the 24v inverters to max+ load without passing the surge to the main bank. The limiting in the buck converter allows me to have a max draw on the circuit until the 24v battery gets back to optimal voltage, then taper back to the constant load.

I have a 48v, 3,000w inverter coming Monday so that will require a re-think on the design.

Interesting, thanks.

So the constant 550W is always drawing ~22A from your 24V Lead-Acid batteries and that ~22A @ 24V is being continuously replenished with ~11A from your 48V LiFePO4 battery through your DC-DC converter (what conversion efficiency does it have?).

So as long as there is 45-50A of charge current available from your solar array, the Epever has no difficulty supplying that 11+ amps while maintaining LiFePO4 battery at Float Voltage.

But once clouds degrade charge current below the ~11A current being continuously drawn by the DC-DC converter (more than 11A once conversion efficiency below 100% is accounted for), then the Epever is able to supply only a portion of the current being drawn by the DC-DC converter, LiFePO4 battery supplies the balance, which drops LiFePO4 voltage below Float voltage to boost reconnect, which initiates a new boost cycle.

And if the cloud passes quickly-enough that Epever Float charge current exceeds DC-DC draw before LiFePO4 voltage drops under Boost Reconnect Voltage, then Float slowly charges LiFePO4 back to Float voltage.

Is that an accurate understanding of how your system functions?

 

[jnrhome]

yes. That's it.

DC-DC conversion is at 95% and the sealed lead acid uses an additional 5 watts or so to maintain the voltage at 26.6v.

Because the draw on my main bank is steady, it weathers passing clouds very well. I supply all the surges with lead acid.

This design was deployed to test surge load capability of the inverters and re-utilize the already purchased 24v sealed lead acid batteries and inverters. Plus, i can use 12awg to distribute 48v to the various locations of the inverters instead of 4 or 6awg. Once i get the 48v inverter, it may change. But, it works really well and i can use the old system parts, as well as provide backup battery for my constant load which carries internet delivery for about 100 subscribers. It also allows me to work on the main system without losing power to that system. The sealed lead acid provides about 12 hours of independent power to the system and could be charged back up by wall power, if necessary. I can disconnect the solar array and work on it, or shut down the lithium battery to work on it without my subscribers suffering for as much as 12 hours at a time.

 

[jnrhome]

Scary Moment
Had a very grey morning, so much less early charge than usual. Around 12:30, hit a bright spot and started cranking in the amps. After bursting to more than 3,000w, then about 5 minutes of 2,900w, my 50 amp controller to battery circuit breaker popped for the first time. I shut down the input right away, but feared for the controller. I put a fan on the breaker and cooled it down, then reset it. The controller came back online and is apparently fine. That's just not a test I would have performed as conventional wisdom seems to be solar input on a controller with no battery causes permanent damage. Ugh...
Another myth dispelled... fortunately
Just ordered a 60A breaker...
2,860w solar array producing greater than 3,000w sustained... nice

 

[RStone13]

I have the older version epever 6415AN. I use MT 50 to program. Below is file with my settings. These work for me. I will give you my understanding of how this all works. In the morning when sun comes up if battery bank is below my "Boost Rec" setting of 26.7v the controller goes into boost/bulk mode at a rate of 27.5v all watts available (my "Boost Charge" setting). When bank reaches 27.0v my "Float Charge" setting, it goes into float mode & cuts back on wattage allowed into bank (like trickle charge). It stays in float until one of two things. #1. bank reaches my "Charge Limit" setting of 27.5v and it stops charging. or #2. banks drops to 26.7v my "Boost Rec" setting and then goes back into boost mode and starts all over again. I use LiFePo4 batteries.

 

[fafrd]

I have the older version epever 6415AN. I use MT 50 to program. Below is file with my settings. These work for me. I will give you my understanding of how this all works. In the morning when sun comes up if battery bank is below my "Boost Rec" setting of 26.7v the controller goes into boost/bulk mode at a rate of 27.5v all watts available (my "Boost Charge" setting). When bank reaches 27.0v my "Float Charge" setting, it goes into float mode & cuts back on wattage allowed into bank (like trickle charge). It stays in float until one of two things. #1. bank reaches my "Charge Limit" setting of 27.5v and it stops charging. or #2. banks drops to 26.7v my "Boost Rec" setting and then goes back into boost mode and starts all over again. I use LiFePo4 batteries.

 

[fafrd]

Appreciate the settings, but I believe your understanding of how your 6415AN is working is slightly incorrect.

Once it enters boost it is charging in Constant Current mode at voltage of 27.5V until it reaches 27.5V (at 60A or highest current available from solar power).

At that point it switches from Constant Current at 27.5V to Constant Voltage at 27.5V (meaning voltage will be maintained at 27.5V but charge current will be steadily reduced as needed to keep battery voltage there).

You have ‘Boost Time’ set to 120min (2 hours) and this governs the duration of this Constant Voltage charging phase. So your 6415AN will maintain a voltage of 27.5V for 2 hours after first reaching it while charging at 60A (or max current available).

After this 120min / 2hr duration of Constant Voltage charging at 27.5V, your 6415AN will enter Float mode at your Float Voltage of 27.0 volts, which it will maintain as long as solar power can supply sufficient current to satisfy any loads.

As long as the 6415AN can supply enough current to satisfy any loads, battery voltage will remain at 27.0V (neither decreasing nor increasing).

Once loads exceed available charge current, the difference will be drawn from the battery and battery voltage will begin to decline.

Once battery voltage drops to Boost Reconnect voltage of 26.7V, the 6415AN will start a new Boost Charge Cycle at 60A or whatever maximum current the solar power can provide.

You can get your 6415AN to drop into Float more immediately after first reaching 27.5V by reducing Boost Time from 120 min to whatever minimum is allowed...

 

[RStone13]

Appreciate the settings, but I believe your understanding of how your 6415AN is working is slightly incorrect.

Once it enters boost it is charging in Constant Current mode at voltage of 27.5V until it reaches 27.5V (at 60A or highest current available from solar power).

At that point it switches from Constant Current at 27.5V to Constant Current at 27.5V (meaning voltage will be maintained at 27.5V but charge current will be steadily reduced as needed to keep battery voltage there).

You have ‘Boost Time’ set to 120min (2 hours) and this governs the duration of this Constant Voltage charging phase. So your 6415AN will maintain a voltage of 27.5V for 2 hours after first reaching it while charging at 60A (or max current available).

After this 120min / 2hr duration of Constant Voltage charging at 27.5V, your 6415AN will enter Float mode at your Float Voltage of 27.0 volts, which it will maintain as long as solar power can supply sufficient current to satisfy any loads.

As long as the 6415AN can supply enough current to satisfy any loads, battery voltage will remain at 27.0V (neither decreasing nor increasing).

Once loads exceed available charge current, the difference will be drawn from the battery and battery voltage will begin to decline.

Once battery voltage drops to Boost Reconnect voltage of 26.7V, the 6415AN will start a new Boost Charge Cycle at 60A or whatever maximum current the solar power can provide.

You can get your 6415AN to drop into Float more immediately after first reaching 27.5V by reducing Boost Time from 120 min to whatever minimum is allowed...

You stated switches from constant current to constant current. I think you meant CC to CV
So your saying boost time doesn't start until you have reached its setting voltage and then will run as long as your setting time before going into float.
Interesting, I will disconnect my load tomorrow and watch it cycle threw. I'll get back to you. Thanks Bruce

 

[fafrd]

You stated switches from constant current to constant current. I think you meant CC to CV

Good catch - thanks (fixed in post).

So your saying boost time doesn't start until you have reached its setting voltage and then will run as long as your setting time before going into float.
Interesting, I will disconnect my load tomorrow and watch it cycle threw. I'll get back to you. Thanks Bruce

That is my understanding (also from direct communication with Epever Support).

With no loads, you should see charge current start to drop as soon as voltage hits Boost Voltage and you should see that voltage being maintained for the full 120 minutes before it begins to drift down to float voltage.

If you are within that 120 minute CV phase and switch on some loads, you should see current out of your 6415AN increase while battery voltage remains constant at Charge Voltage (as long as available solar power is sufficient to supply that full load current).

I’m planning a system around a 24V (8S) LiFePO4 battery as well, so I’ll be interested if you are able to confirm that your 6415AN functions as described...

 

[RStone13]

Good catch - thanks (fixed in post).



That is my understanding (also from direct communication with Epever Support).

With no loads, you should see charge current start to drop as soon as voltage hits Boost Voltage and you should see that voltage being maintained for the full 120 minutes before it begins to drift down to float voltage.

If you are within that 120 minute CV phase and switch on some loads, you should see current out of your 6415AN increase while battery voltage remains constant at Charge Voltage (as long as available solar power is sufficient to supply that full load current).

I’m planning a system around a 24V (8S) LiFePO4 battery as well, so I’ll be interested if you are able to confirm that your 6415AN functions as described...

Yes I'll get back to you. Disconnecting load only so I reach the voltage point of contention faster. Then it will be beneficial to reconnect load for same reason.

 

[RStone13]

You said, I’m planning a system around a 24V (8S) LiFePO4 battery as well, so I’ll be interested if you are able to confirm that your 6415AN functions as described. Here is a simplified sketch of my system. Inverter is split phase and its connected to a fuse box.

 

[RStone13]

Ok I have spent the last couple days monitoring my system closely as it cycles. I was wrong and you were correct about how the controller goes through the cycle. Thank you for pointing out my misconception about that. This is how we learn from each other. Had to change most of my settings, and its running good. Thanks Again Bruce

 

[RStone13]

My new settings these seem to be working fine.

 

[jnrhome]

so I've had some confidence build as I slowly adjusted settings up, top balanced a bit, adjusted up, etc. The controller was appropriately responsive and took my settings changes pretty quickly and repetitively. After topping out the settings, I let it run for a few days to confirm that it was all good. Everything behaved so yesterday morning, I adjusted the settings down to the final set of conservative settings and expected everything to drop into place. The controller ignored them and continued to charge with the high settings. I let it go yesterday to see. Today, same thing. Ignored my new settings and pushed right past them. I reset to lifepo4 default and adjusted settings to the new ones, and it ignored them again. I'll let it go through tomorrow again to see if it takes an extra day...

 

[Pacer]

My new settings these seem to be working fine.

Thank you for this! I’ve been struggling with finding the right settings for a conservative charge profile like this, my previous experiments did not work (SCC was charging above my “set” values).

I am using the Bluetooth module to connect, the good news is that the setting that I input are accepted and the Bluetooth connection is very reliable.

 

[RStone13]

Thank you for this! I’ve been struggling with finding the right settings for a conservative charge profile like this, my previous experiments did not work (SCC was charging above my “set” values).

I am using the Bluetooth module to connect, the good news is that the setting that I input are accepted and the Bluetooth connection is very reliable.

Glad you like them. They work for me.

 

[Pacer]

Glad you like them. They work for me.

I thought this may work, but my SCC is still ignoring the high voltage charge limit. Hmmm. I don’t seem to be alone with this issue!

 

[Pacer]

I have read through this thread a few times, and want to get a consensus on something.

Are others experiencing the same thing where the SCC won’t accept the new settings right away? Is there a typical time delay for the new settings to take effect?

I’m starting to get frustrated with this controller, especially after all of the other (unrelated) roadblocks that I have experienced.