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ICC
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# Posted: 25 May 2024 05:01pm
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Back in 2011, maybe 2012, I upgraded my cabin solar power equipment. I used a Midnite Solar The-Kid MPPT charge controller that was a pre-production test unit. It has performed excellently ever since. (150 volt, 30 amp max). It was superb for my old lead acid batteries. However, I discovered one deficiency for some LFP battery use, and there is no firmware fix for it. More on that later.
I replaced it with. Victron Smartcharge charge controller, 150 volt, 35 amp max. I installed it yesterday. Installation was easy and it connected the the Victron app quickly, did a firmware update and started charging. Simple and straightforward setup. Today has been somewhat cloudy and we are already at almost 100%, but to be fair The Kid was very quick at charging too.
Why replace a controller that in almost all respects was working fine? There are some nice features but most of those are just gravy.
The SOK BMS with Bluetooth has a sleep mode and a storage mode. The BMS goes into sleep mode when there is no discharge or charge current detected. This is good. There is a very low discharge current, measured in mA that keeps the electronics live to watch for a charge or discharge current. If either is detected the BMS wakes up and the system works.
Storage mode is a manually selected setting that shuts the BMS down completely. The external battery connections are stone cold. No power. No danger from an accidental short curcuit for example. No small current drain at all. I like that for times when the system may not be needed for an uncertain interval, like over a winter.
Here's where the deficiency comes. When the SOK BMS is in storage mode only a charge current can wakeup the BMS. (In sleep mode a discharge can wake the BMS, even a low current such as a small DC power LED light)
The Kid charge controller is one of a few designs that will not turn on, or activate, until it senses the battery voltage. In storage mode, the SOK terminals are dead, no voltage. The Victron controller, on the other hand, stores the battery voltage in ROM memory. It has the ability to wake the BMS from storage mode once the PV panels receive enough sunlight to provide a usable voltage. Therefore I don't need to run the generator to wake the BMS from sleep.
After Victron dropped their prices last winter I decided to go for it.
Now I have a spare, or may see if I can sell The Kid. It is still in the Midnite Solar lineup. A new Victron is cheaper though and the Bluetooth app is very nice to have. So if I sell it would be a relatively good price.
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ICC
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# Posted: 25 May 2024 05:04pm - Edited by: ICC
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That is not the tidiest wiring I have ever done. It is functional. The breaker at top left is from the PV array. The breaker at lower right is to the battery. Large black cable from bottom left is power from the PV array.
Next, I have a Victron SmartShunt to install, but I forgot the hacksaw I need to cut the buss bar.
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Nobadays
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# Posted: 25 May 2024 06:52pm
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I installed the same SCC on my shop system last fall when they went on sale. Pleased with it's ability to harvest power on cloudy/partly cloudy days, and ease of setup. My only beef is the "smart absorption" with my AGM batteries. The algorithm it uses to adjust the absorption time is complicated (to me) and I don't believe it is allowing enough absorption time. Of course with your LFP, no worries!
I used my shop system to power the Starlink for nearly two months last fall before we left for the winter. Starlink ran flawlessly until about the first part of February when I started noticing early mornings it would be off. I blamed it on snow so lack of sun on my panels. However when I arrived in mid May to get things opened up I noticed it was shutting down every morning. This even though the batteries were floating every day. Started looking at what might be the issue since these 225ah AGMs were new last fall and have enough reserve power to run the Starlink for nearly 3 days.
My best guess, after noticing the absorption time is very short, most days 30 to 40 minutes max, is that these AGMs are sulfated and just will not hold a deep charge as they should. A battery load tester shows they are good but right on the edge of weak.
I'm going to "lightly equalize" them for several days as clear skies permit. Though with most AGM (Lifeline being the exception) equalization is not recommended, I am not the first to do so, and I think I can bring them back.
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ICC
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# Posted: 25 May 2024 09:27pm - Edited by: ICC
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Still at a low price. In fact today is $5 less than Dec 2023 when I bought mine. At that time we already had too much snow for cabin access, but I had no certainty the price would stay low.
You can make a custom user preset charge profile in the Victron app in the battery section of the settings. And save it to the presets included. The downloadable user manual may help to sort it out. I have made one for my SOK LFP as their recommendations are a little different than the preset LFP switch selectable setting.
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Nobadays
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# Posted: 25 May 2024 10:38pm
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Quoting: ICC You can make a custom user preset charge profile in the Victron app in the battery section of the settings.
I am using the "user defined" settings. I didn't see where I could set a time for length of absorption. I'll go back and see if I can figure it out.
Thanks!
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ICC
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# Posted: 26 May 2024 12:44am - Edited by: ICC
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I can't say for where you will find AGM parameters, but I did find absorption time when I was bumbling around the settings looking to make a custom, user defined preset profile for LFP. Off hand I don't recall where or how I got there. Now I am at home and have no idea if I can or how to access the device settings without being able to access the charge controller via bluetooth. Not sure when I am going to be back there as I have a series of appointments in the city over the next couple of weeks.
I must admit that there deems to be so many settings that can be adjusted I have trouble following it all. I am more of a real-time hands on learner (bumbler) than a pure book learner.
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Nobadays
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# Posted: 26 May 2024 01:36pm
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Thanks ICC... I went out yesterday and did indeed find where I could set a defined absorption time. You're right there seems to be an infinite amount of settings, and I like that to a point!
I still think I need to equalize these batteries a few times. I'll plug the Starlink back into the shop system after I've done that to see if it will run all night again. I do think I've lost a good bit of capacity which bums me out. Batteries aren't cheap!
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travellerw
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# Posted: 26 May 2024 08:55pm
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I'm a major Victron fan these days. With the price drops there is just no reason to try and save money by buying chinese off brands. Victron just works.
Quoting: Nobadays I still think I need to equalize these batteries a few times. I'll plug the Starlink back into the shop system after I've done that to see if it will run all night again. I do think I've lost a good bit of capacity which bums me out. Batteries aren't cheap!
I run an equalize every 30 days on my FLA batteries. It helps keep them from sulfating the plates. I have also seen some pretty beat up batteries come way up in capacity from a couple of good long equalization sessions. So I have hope yours will come back.
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gcrank1
Member
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# Posted: 26 May 2024 09:52pm
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It is worth a couple tries, Ive got some extra life out of a few.
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paulz
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# Posted: 26 May 2024 11:30pm - Edited by: paulz
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Quoting: ICC I must admit that there deems to be so many settings that can be adjusted I have trouble following it all. I am more of a real-time hands on learner (bumbler) than a pure book learner.
I’m a lifelong member of that club! At least you guys have provoked me into checking the boost and equalization parameters on my Epevers.
Cabin controller has no setting for LFP, it’s at “user” that I have set from recommendations as follows:
Battery type user
Over voltage disconnect 14.0
Charge limit 13.8
Over voltage reconnect 13.6
Equalization charge 13.8
Boost charge 13.8
Float charge 13.6
Boost reconnect 13.3
Low voltage reconnect 12.6
Under voltage reconnect 12.2
Equalization time 0
Boost time 180
Down the hill at my shop is another Epever, generally hooked to whatever FLAs are not in a tractor, log splitter or something. These settings are preset by Epever for “Flooded”
Battery type flooded
Over voltage disconnect 16.0
Charge limit 15.0
Over voltage reconnect 15.0
Equalization charge 14.8
Boost charge 14.6
Float charge 13.8
Boost reconnect 13.2
Low voltage reconnect 12.6
Under voltage reconnect 12.2
Equalization time 120
Boost time 120
Feel free to criticize
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Brettny
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# Posted: 27 May 2024 12:14am
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Victron is what I plan on useing when I upgrade my CC. To get another epever it would only cost $20-30 less to get s victron with all that data on a App.
4yrs ago when I got my Epever a victron was about 50% more than the epever. My current is a epever BN (150v 40a). I'm putting more pannel in more sun on my cabin so a 60-70a CC is needed.
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ICC
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# Posted: 27 May 2024 12:41am - Edited by: ICC
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Quoting: Brettny I'm putting more pannel in more sun on my cabin so a 60-70a CC is needed.
Or do more or less as I have at home. 3 CC with 3 separate arrays. Two fixed, one on an 18 yr old tracker from my first serious solar system with the two newer fixed arrays, pointing in different directions. It gives redundancy and more hours of output throughout the day. No need for a tracker these days as panels are much less costly than they used to be.
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ICC
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# Posted: 27 May 2024 12:47am
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One fixed array is eastern facing, the second points a little east of south. The tracker follows the earth rotation of course. The fixed array directions were selected because when we do have cloudy summer days the clouds build after 1 PM or so.
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Brettny
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# Posted: 28 May 2024 12:09am
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That's also how I would handle things too. More pannels pointed different directions. My array will all be roof too mount. No sun exposure on the ground here with 60' trees all around.
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ICC
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# Posted: 30 May 2024 11:22pm
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Today I installed the Victron Smartshunt on the cabin solar system. It was a very easy install, connected to my phone bluetooth right off with no issues. It is nice to have both the shunt and solar charge controller accessible on the same app. The screenshot shows the data while dinner was warming in the microwave.
That view may be expanded to display more data from any one of the connected devices.
The SOK battery was at 100% when I started warming. I noticed that the Victron controller switched to bulk charge more quickly than the old controller did in the past, under similar sun conditions.
All-in-all I am pleased.
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Steve_S
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# Posted: 31 May 2024 11:11am
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Pretty hard to go wrong with Victron Gear which will probably outlast you & me.
I use Midnite SCC's which are also great Solar Controllers albeit too pricey now days but they are Long in the Tooth when it comes to Firmware/Software and they do not interact with other gear directly (can be kludged). I've been pondering changing to Victron SCC's for the past 2 years and now with my new Battery Bank with the JKBMS "Inverter Edition" which can directly interface with Victron for far better control etc.
Gee Wiz, I am going to have to have a Solar Gear Yard Sale when I am finished finalizing out my system. From gently used to New in Box; BMS', Relays, Contactors, Shunts and oh so much more...
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Brettny
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# Posted: 31 May 2024 11:42am
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I had looked at the victron smart shunt. How do you like it? I havent used a battery monitor before and will be moving my temporary system to its permanent home..a battery monitor is one of the things I really wanted to add. It's really hard to tell what's really happening with capacity without one.
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ICC
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# Posted: 31 May 2024 07:25pm - Edited by: ICC
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My old Midnite SCC will live on in a neighbor's small cabin system.
Quoting: Brettny I had looked at the victron smart shunt. How do you like it?
With the old Midnite SCC I used their Whiz Bang Jr shunt based battery monitor. It works in a similar manner to the Victron Smartshunt, but uses the display on the SCC. No app, not as handy but still useful. That was lead-acid batteries until I changed to the SOK LFP last year.
I like the Victron Smartshunt a lot, as it has the phone app via bluetooth. It is more convenient to read and you don't have to switch screens to see the next data. I briefly considered an off-brand copy but did not go that way as Victron is a known quantity and Victron products that are "smart" share the one app... VictronConnect.
For LFP batteries I feel a good battery monitor is essential.
It is interesting to note that the VictronConnect app contains all the upgrade data that is required when Victron products need a firmware upgrade. That is applicable to their bluetooth compatible items. Anytime the app gets an update there may be a upgrade for something else. So, no internet needed where the SCC is located, for example. When you use the app it will inform you that an upgrade is ready. The Midnite equipment required me to take a laptop with the downloaded file and use a usb cord to upgrade. Victron does it from the phone app via bluetooth. I do not have any idea how their non-smart items are firmware upgraded.
The SOK battery BMS has a monitor app, but it is not shunt-based, and therefore provides a theoretical SOC, IMO. The SOK app does provide voltage readings for each cell though so it can still be a valuable tool. Presently there is a max difference of 0.006 volts between the 8 cells.
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