Is EPEVER MPPT solar charge controller capable of low temp shut off?

jdhahn1

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Hi! I'm in the process of designing a small 24V solar system for an off grid cabin. The cabin will be well below freezing a lot of the winter, so I'll definitely be running into the scenario where the battery is too cold to take a charge and potentially even too cold to discharge at times. Does anyone know if the 40A EPEVER charge controller is capable of low temp shut off? I'd prefer to set that a few degrees higher than the BMS low temp shut off on the Battle born battery. Here's a link to the charge controller https://www.amazon.com/gp/product/B07429RK43/ref=ox_sc_act_title_10?smid=A2P9F29Y7BYBUO&psc=1.

I'll also have a generator to charge the battery bank before leaving for extended periods of time if needed. My thought was that I could disconnect the battery (fully charged) when leaving for several weeks so that I know I won't damage anything, but I'd like to have the low temp shut off as additional protection if the cabin gets too cold while the system is live.

System will consist of:
4 x 100W solar panels
EPEVER 40A charge controller
1200W Inverter
24V 50AH Battle Born Battery

It will primarily be used for low voltage lighting, charging portable devices, and occasionally charging power tool batteries (all other appliances are propane). I think I've sorted out most of the details, but if anything strikes someone as wrong or if there are things I'm not thinking about I'd love feedback.

Thanks!
 

fratermus

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Does anyone know if the 40A EPEVER charge controller is capable of low temp shut off?
None of the EpEver controllers I am aware of have a low temp cutoff. A temp controller with a relay could handle those duties, though controller might get nervous if the battery bank went away suddenly.

Have you totally ruled out using lead batts? This whitepaper from Trojan shows FLA at 85% SoC can handle lower than -60F. That would be a reasonable if there were no active loads on the batts while you are away. Dunno how gel/agm behaves in extreme cold.
 

12VoltInstalls

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You have to have certain circumstances where fla batteries make sense. Usually.

As mentioned above: In your case, I’d be inclined to seriously consider lead batteries. Being without lights fridge, whatever, when it’s cold outside would annoy me. Probably your lfp batteries would be inside, but the ingested/vacant times I can see your concern.
if you have enough fla batteries to not deep discharge regularly even the inexpensive walmartha marine batteries can last 5 years+ in my experience.
 

Tecnodave

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EPever controllers do not have a low temperature shutoff, they were designed long before lithium requirements were known, some will let out the magic smoke when battery is disconnected and input power is present, This includes the 3210 AN and 4215AN. Voltage stability was horrible, after destroying a set of large format L-16 FLA’s due to mis charging they were sold as-is and i bought high quality. no more EPneverreliables for me.


<EDIT> that probably was a 3215AN and 4210 AN, i'm trying to flush that bad experience....
 
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Symbioquine

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I just tested with a Tracer1210AN and a Tracer8420AN and confirmed that both correctly cut off charging when the temperature drops below the configured values when "LiBattery Protection" is enabled.

Those values can be set via the Epever "Solar Station v1.95" software from their site or via modbus as I'll detail below...

The low temperature setting value is in the modbus register 0x9010 and only has an effect when the "LiBattery Protection" setting is enabled - that setting appears to be stored in the modbus register 0x9107 which seems to be a bitset where 0000010000000000 corresponds to "LiBattery Protection" setting disabled and 0000001100000000 corresponds to "LiBattery Protection" setting enabled.
 

Tecnodave

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those models are far newer than the ones that i had, mine had no reference to lithium charge cycles at all
 

Symbioquine

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It would be interesting to compare the SW/HW version numbers you're talking about against mine, but I suspect most of the recent Epever controllers in the AN line have support for the low temp cutoff.

Perhaps it's important to mention that there doesn't seem to be any way to access the feature through the controller itself or even through the MT50 display. I think it can only be enabled with the Epever computer software or perhaps via their bluetooth phone app. (Or obviously via custom hardware/software that uses the same RS485/Bluetooth interfaces.)
 

iamrich

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Insulated battery box with small heater mats might work? I would probably just unhook the battery pack before you leave by adding a switch.
 

Tecnodave

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After the EPever’s were not able to charge my high end FLA set with far too low a voltage to finish float much less even do a equilization charge they were replaced with charge controllers that are capable of real deep cycle batteries and sold as is , never looked back, I have the real deal.....
 

durval

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Hello everyone, I have an EPEver TraceRT3210AN V01.55+V01.22 bought about 1 year ago, and I have never had to test it (no freezing temps around here) but it does have low-temp charging cutoff: it's both described in the manual and accessible/settable on the EPever configuration software.
 

Symbioquine

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Not sure on those models but I think that’s a low-temp attenuation offset value not a cutoff?

It certainly seems to behave like a cutoff. My testing procedure involves the following settings;

VirtualBox_Windows 7_15_07_2021_06_33_41.png VirtualBox_Windows 7_15_07_2021_06_34_03.png

Then I confirm it's charging;

VirtualBox_Windows 7_15_07_2021_06_19_24.png

Then I stick the temperature probe in a thermos with ice and salt to bring the temperature below freezing;

VirtualBox_Windows 7_15_07_2021_06_27_53.png

At which point the controller and my bench power supply seem to agree that it's not charging from the solar input. (The controller says "Solar Status=Cut Out", "Charging Status=Not Charging", "Battery Current(A)=0.00", and "Battery Status=Under Min Temp." while the bench power supply drops to a negligible amperage draw.)

Here's a recording of that all happening; (Just the software side, since my desk is too chaotic right now to include in an actual video.)

Peek 2021-07-15 06-27.gif
 

Symbioquine

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The device I was testing with there was a Tracer1210AN; (A previous test with a Tracer8420AN yielded the same behavior.)

Code:
TriRon1210
V01.55+V01.22

2021_07_15_tracer1210an_device_info.png

I have no affiliation with Epsolar (Epever) nor even any ties in the solar/off-grid/energy industry. This is just a (mostly) happy customer, reporting that the observed behavior of these devices (I have 4 in operation right now) has thus far exactly matched their specs and the documentation. I have found these devices to be pleasantly hackable and somewhat - if not thoroughly - well documented.
 

pollenface

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After the EPever’s were not able to charge my high end FLA set with far too low a voltage to finish float much less even do a equilization charge they were replaced with charge controllers that are capable of real deep cycle batteries and sold as is , never looked back, I have the real deal.....
Which charge controllers did you opt for?
 

Tecnodave

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MidNite Classic 150 for the following reasons...

1) every single parameter can be accessed from the control panel
2) no external device needed to control or monitor
3) the best tech support by far, allways an answer and not just from some sales person, I have discussed issues with boB Gudgel and Robin Gudgel , there is no sluffing off customers at MidNite, they truly do care about the enduser
4) if there is an issue MidNite does deal with it and promptly to its resolution
 

Tecnodave

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I think about 5 years now and ive had only one issue with a Classic......I was moving my first one from my test location , i bumped it too hard and broke the terminal strip cover over the solar in, battery connections, and it fell into the fan tray which caused a buzzing noise, damaging the fan blades. Even though i broke it, and admitted it, the crew at MidNite shipped me a new terminal strip and fan at no cost to me. No hassle at all....

Years later....
Two Classics, Two Kids, E-panel for my MagnaSine, combiners , DC-15 panel, big baby boxes......at least 80 MidNite items in my power shack......too late to look back now, patiently awaiting a MidNite Rosie the inverter.

Yep, they are expensive, Yep they have a very good reliability....AND , by far the best customer support ever..

Tecno...
 

12VoltInstalls

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device I was testing with there was a Tracer1210AN; (A previous test with a Tracer8420AN yielded the same behavior.)
Fascinating.
I will need to look at my parameters and see if I can’t keep charging at low temps because that’s probably going to be important. (Lead Acid batteries)
Using 4210AN new only a few months ago. I’d imagine the programming is comparable.
Thank you for your post.
 

alaric michael

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That is good. I will need to look at my parameters and see if I can’t keep charging at low temps because that’s probably going to be important. (Lead Acid batteries)
Using 4210AN new only a few months ago. I’d imagine the programming is comparable.

Good post ..
 

Tecnodave

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Lead acid batteries can be charged at low temperatures but make sure that if you get to freezing temperatures keep the batteries at or above 50% charge levels, the more charged the batteries are the lower the freezing point of the acid mix. At 1.265 specific gravity they will not freeze at 60 below zero but if dead they will freeze at a much higher temp than that. If you do freeze a lead acid battery, DO NOT CHARGE...., let it thaw out real good then charge, they will survive this but its not a good habit. We used glue on battery heaters in Alaska to keep car batteries above 40-50 degrees F.
 
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