Category Archives: LifePo4

Using Home Assistant Kasa Matter Plugs and a Victron MPPT VEDirect cable to deplete your batteries for next day — Updated Version

In my last version I used home assistant to connect to KASA matter plugs, I have found nothing but problems with matter, especially kp125M plugs, that use matter. One day I was turning on and off grid breakers and then I had to delete devices from google and home assistant because they could not connect using matter anymore! In this version we will use non-matter KASA smart plugs and skip home assistant. You can review what we did before here: https://blog.sunsaturn.com/freebsd/using-home-assistant-kasa-matter-plugs-and-a-victron-mppt-vedirect-cable-to-deplete-your-batteries-for-next-day/

In this version since we used 2 different scripts accessing a lot of same functions, makes no sense to keep it that way, so let’s stick our functions for KASA plugs and Victron’s VEDIRECT in a separate class file, and remake our 2 scripts for our cronjob.

Let’s start by creating a file called victronclass.py to hold our 2 functions, and add following to it:

import vedirect
from kasa import SmartPlug

class VictronApp:
    def __init__(self):
        pass

    async def victron(self, serial_port, serial_baud):
        try:
            device = vedirect.VEDirect(serial_port, serial_baud)
        except Exception as e:
            print(f"VICTRON [FAIL] : Read bad data: {e}")
            return False
        try:
            float(device.battery_volts)
        except Exception as e:
            print(f"VICTRON [FAIL] : Return type was not a float: {e}")
            return False
        if not device.battery_volts > 0:
            print(f"VICTRON [FAIL] : Voltage not greater than 0!")
            return False
        print(f"VICTRON [SUCCESS] : Voltage is {device.battery_volts}")
        return device.battery_volts


    # Usage: status = await kasa_plug(IPADDRESS, "on/off/check")
    # Returns True if plug turned on or off or if "check" is used returns True if plug is on
    async def kasa_plug(self, ip, cmd):
        p = SmartPlug(ip)
        try:
            await p.update()
            if cmd == "check":
                if p.is_on:
                    print("KASA [CHECK] : Plug is on")
                    return True
                else:
                    print("KASA [CHECK] : Plug is off")
                    return False
        except Exception as e:
            print(f"KASA [FAIL] : Exception received connecting: {e}")
            return False
        if cmd == "on":
            if p.is_on:
                print("KASA [SUCCESS] : Plug already on doing nothing")
                return True
            else:
                try:
                    await p.turn_on()
                    await p.update()
                    if p.is_on:
                        print("KASA [SUCCESS] : Turned Plug on")
                    else:
                        print("KASA [FAIL] : Plug still off after turning it on")
                    return p.is_on
                except Exception as e:
                    print(f"KASA [FAIL] : Exception Received Turning on Plug: {e}")
                    return False
        elif cmd == "off":
            if p.is_off:
                print("KASA [SUCCESS] : Plug already off doing nothing")
                return True
            else:
                try:
                    await p.turn_off()
                    await p.update()
                    if p.is_off:
                        print("KASA [SUCCESS] : Turned Plug off")
                    else:
                        print("KASA [FAIL] : Plug still on after turning it off")
                    return p.is_off
                except Exception as e:
                    print(f"KASA [FAIL] : Exception Received Turning off Plug: {e}")
                    return False
        else:
            print("KASA [FAIL] : INVALID ARGUMENT: use [on] [off] or [check]")
            return False

We created 1 class to hold both our KASA and victron vedirect functions, that way we can reuse these in our 2 main files. Let’s create our first main file for our cronjob and call it victron.py:

import asyncio
from victronclass import VictronApp

async def main():
    # Config START
    # VICTRON
    # trying 25.9(35% spring getting 4KWh per day atm)
    voltage_max = 25.9          # we don't want voltage higher than this for morning solar charging--leaving it at 50% each night
    # https://batteryfinds.com/lifepo4-voltage-chart-3-2v-12v-24v-48v/
    serial_port = '/dev/cuaU0'  # serial_port for VEDIRECT, on linux try "setserial -g /dev/ttyUSB[01]" to find your serial port
    serial_baud = '19200'       # serial baud rate, 19200 seems recommended setting from Victron
    # KASA PLUG
    # kasa_ip = '192.168.0.x'    # Ip address of your Kasa plug
    kasa_ip = 'grid_plug'       # Ip address or /etc/hosts name of your Kasa plug
    # Config END

    v = VictronApp()
    # check voltage of battery
    volts = await v.victron(serial_port, serial_baud)  
    if not volts:
        print(f"ERROR: no volts, exiting program....")
        exit(1)
    kasa = await v.kasa_plug(ip=kasa_ip, cmd="check")

    if kasa:  # if plug is on
        # plug is on, check it we need to turn it off
        if volts > voltage_max:
            print(f"Voltage is greater than {voltage_max} Turning off Grid Plug")
            await v.kasa_plug(ip=kasa_ip, cmd="off")
        else:
            print(f"Grid Plug is on and voltage less than {voltage_max} DOING NOTHING")
    else:
        # plug is off, check it we need to turn it on
        if volts < voltage_max:
            print(f"Voltage is less than {voltage_max} Turning on Grid Plug")
            await v.kasa_plug(ip=kasa_ip, cmd="on")
        else:
            print(f"Grid Plug is off and voltage greater than {voltage_max} DOING NOTHING")

asyncio.run(main())

Now you can add this to cron as follows:

*/10 23 * * * (/root/cronjobs/victron.py) > /dev/null 2>&1
*/10 0-6 * * * (/root/cronjobs/victron.py) > /dev/null 2>&1

This should allow you to depleted your batteries between 11pm and 6:50am each day.

Now let’s create our program to turn on the grid KASA plug no matter what at 7am, let’s call it grid_on.py:

import asyncio
from victronclass import VictronApp

async def main():
    # Config START
    # kasa_ip = '192.168.0.x'    # Ip address of your Kasa plug
    kasa_ip = 'grid_plug'       # Ip address or /etc/hosts name of your Kasa plug

    # Config END

    v = VictronApp()
    kasa = await v.kasa_plug(ip=kasa_ip, cmd="on")

asyncio.run(main())

and add that to your crontab as follows:

0 7 * * * (/root/cronjobs/grid_on.py) > /dev/null 2>&1

Great your all set with new improved version not using home assistant for KASA anymore. After reading up on matter protocol I am not to fond of it. Not only does it use IPV6, it takes a IPV4 address on your home network if it becomes a border router. Most devices try to become a border router, in fact different companies fight over fact they should become it, then you got all these devices that are border routers.

So to make more of a headache for you , now you have to track those down and deal with them, whether you VLAN them off or just block them completely on your firewall.

I think what is safer is just have 1 hub communicating with a bunch of zigbee devices, at least zigbee devices don’t suddenly attempt to become border routers on your network and do as they please. Like phillip hues lights for instance, you just have one hub to deal with if it’s misbehaving in anyway, not have to deal with every single light trying to become a border router lol. For smart plugs you definitely want full control at all times with a definite IP address. Things like light bulbs should never be matter devices attempting to become border routers. If someone is going to hack your home network , they shouldn’t be able to plant a backdoor on your light bulb that became a border router, they should need to be in range, not in China!

Ultimate security is keep everything zigbee etc, and use your own server to control all the zigbee devices on home assistant, then you don’t even have to worry about a phillips hue hub etc doing bad things on your network. Or if your crazy security conscious I guess look for a smart plug that is zigbee/bluetooth etc controllable.

So probably your best bet with KASA is their kp125 without the “M” on the end. This way you get energy stats as well turn plugs on and off as you please. Other versions like their ep25 etc stay far away from, if you loose internet at your house, they require authentication to cloud to use them. WHY ON EARTH? No idea, great right, internet goes out and now you lost control over your devices! Unreal.

I mean this is whole reason people use Home Assistant etc in first place. If internet goes out, telling google to turn on a simple light is replied with, “Sorry I don’t care about you anymore your internet is down blah blah”….. let’s hope it’s not someone’s pacemaker one day!

As for more revisions to this program, if I get my hands on a Cerbo GX one day, I’ll probably update for that using TCP instead of serial for vedirect. Or I may update it to be just one long running program at some point that accommodates for winter/spring/summer/fall, as well as maybe weather conditions. I mean you can get like 4KW a day on 4 panels or more when sun in shining but in winter and cloudy days you get almost nothing, so after I get a year’s history of my solar I’ll have a better idea how to proceed.

Keep in mind you could always use a hybrid inverter for switching, although I don’t think it would support depleting your batteries to a certain voltage at night lol. Also honestly they all suck, their switching times are horrendous, like 10-20ms, that would knock out my old servers, and any old electronics instantly. Better is a straight up inverter and use a real PDU like a Tripplite on ebay. You can get them fairly cheap these days, and you get sub 2ms switching times, then your golden…

Till next time…

SunSaturn

Using Home Assistant Kasa Matter Plugs and a Victron MPPT VEDirect cable to deplete your batteries for next day

Wouldn’t it be nice to automate depleting your batteries at night so that you have unwasted electrons coming in next day from your solar panels? My setup is a Kasa matter plug for grid and a Kasa matter plug for solar going into a PDU as an automatic transfer switch. So at any point on my phone I could turn off the grid plug and let the batteries drain for next day, but that is manual labor so we should automate it with python.

I am going to do this on FreeBSD, but would work for Linux etc. as well by changing your serial port for VEDirect, so we’ll just make that a configuration option. Another reason I’m going to use home assistant for turning plug on or off, is they are matter plugs, the kp125m to be exact, so just using python-kasa or whatever is not going to work for matter plugs(not currently anyways). However we can use Home Assistant API calls to turn them off or on.

And I know there is going to be someone saying why not just use a Victron Cerbo GX instead and use a TCP port on network. Fair enough, just don’t have one yet, so I’ll just run the VEDirect cable to my servers USB port and do it that way for now.

Alright let’s get started, figuring out voltage max…

First thing we have to do is figure out a battery voltage max that we want to have for next day before sun comes out. So I’m going to do this by example so you can figure out yours. In my setup I have 280AH lifepov4 batteries @24V. Now I know right now it’s winter time and most I’m going to get a day is 2Kw a day off my 920watts of solar panels from my Victron history graphs on the app.

so math: 1Kw = 1000w / 24V = 41.6 amps (24V might actually be 26.blahV for absorption voltage, but whatever) So 41.6 x 2 = 83.33 amps for 2Kw. So I need to drain batteries 280ah – 83.33ah = 197 AH. Now that I know I need it at 197AH each day to not have wasted electrons, I need to look at a chart:

https://batteryfinds.com/lifepo4-voltage-chart-3-2v-12v-24v-48v/

Chart is in percentages, so now I need to convert that 197AH to a percentage so I can match up voltages with it. So let’s do that, 197AH/280AH*100=70.35%. Great now I have a percentage so I can cross reference that chart at 70% to see what my max voltage should be. According to chart, 70% is 26.4V. Perfect we are golden, but remember to adjust this for summertime when your getting 6-7 Kw a day instead!

Installing pre-requisite packages

For VEDirect we’ll use the vedirect module. For Home Assistant all we’ll need is pythons requests and json libraries to keep it simple. For FreeBSD:

pkg install py39-pip py39-requests
pip install vedirect

Figuring out what we need to code

So what I’m thinking is we need 2 python scripts, one to turn on or off the grid plug depending on the voltage, and a 2nd to turn it on no matter what before sun comes out. We will toss the 2 scripts in a cronjob , so first one runs every 5 minutes between 11pm and 6:50am, and 2nd one to run at 7am to turn on grid plug no matter what.

Now we will need 2 things from Home Assistant, so let’s login there. First we need an API long lived token for accessing the API, you can find this by clicking under developer tools and settings on your nav bar. Just click on your name at very bottom. Now scroll all way to bottom and click “create token”. Copy it and save it for later.

Next we need to know what Home Assistant actually calls our plug, not the name we gave it, also called the “entity”. For that just go to your home screen, click on your plug and go to settings icon. In there you should see something called “entity ID”. Copy that as well, that’s how we talk to home assistant.

Let’s code the 2nd script first as it should be shorter….

First Python script to turn on the plug

Let’s call this one ha_grid_on.py :

#!/usr/local/bin/python3.9

#pkg install py39-pip py39-requests

import requests
import json
import time

def plug(address,token,entity,state):
   #returns on/off with "state=check" else 1
   if state == "on":
      url = "http://" + address + "/api/services/switch/turn_on"
      req = "requests.post(url, headers=headers, json=data)"
   elif state == "off":
      url = "http://" + address + "/api/services/switch/turn_off"
      req = "requests.post(url, headers=headers, json=data)"
   elif state == "check":
      url = "http://" + address + "/api/states/" + entity
      req = "requests.get(url, headers=headers)"
   else:
      print(f"SunSaturn# [FAIL] : Only off/on/check should be called")
      exit(1) #exit program no point doing anything
   #print(f"url is {url}")
   #print(f"req is {req}")
   data = {"entity_id": entity}
   #print(data['entity_id'])
   headers = {
      "Authorization": "Bearer "+ token,
      "content-type": "application/json",
   }
   try:
      response = eval(req)
   except Exception as e:
      print(f"SunSaturn# [FAIL] : Failed connect to home assistant: {e}")
      exit(1) #exit program no point doing anything   
   if not response.ok:
      print(f"SunSaturn# [FAIL] : Failed response code not 200: {response.text}")
      exit(1) #exit program no point doing anything
   check = json.loads(response.text)
   if state == "check":
      check = json.loads(response.text)
      return check['state']
   return 1


#CONFIG - EDIT ME
#######################
#HOME ASSISTANT
#HA assistant token
address='ha:8123'                     #Home Assistant API [IP:PORT]
                                      #HA token, create one in HA
token='eyJhbGciOiJIUzI1NiIsInR5dCI6IkpXVCJ9.eyJpc3MiOiIyYmQ1MDM0YTg2NjY0NDIzOWZlZjg2NmZiNGY4N2E7MyIsImlyuCI6MTcwMTk5MTU3OCwiZXhwIjoyMDE3MzUxNTc4fQ.swUTIoUFWbXEul3JuWRRiKpE-Ene-kKeM1ch8uNQF5o'
entity='switch.kasa_smart_wi_fi_plug' #grab entity of Grid Plug from settings for device on homepage of HA
#######################

plug(address,token,entity,"on") #last arguement can be 1 of on/off/check
print(f"Turned on Plug, checking if it's really on...")
time.sleep(1) #we need a sleep of 1 to give HA time to update
check = plug(address,token,entity,"check")
if check == "on":
   print(f"YEP")
else:
   print(f"NOPE")

Ok I stuffed most of logic in a function, also since all we care about is the script just failing anywhere it fails, we just stuff a exit(1) anywhere to stop execution instead of returning from function. Next we setup configuration variables to edit like the token and entity we got from HA already. Only other config we need is the IP:port. Adjust this for your own HA, I have just ha in /etc/hosts pointing to its real IP.

Next we turn the plug on, then do a check to see if it’s actually on as well. Pretty simple script, first one done.

2nd python script

Let’s called this one victron.py:

#!/usr/local/bin/python3.9

#pkg install py39-pip py39-requests
#pip install vedirect 




import vedirect
import requests
import json

def victron(serial_port, serial_baud):
   try:
      device = vedirect.VEDirect(serial_port,serial_baud)
   except Exception as e:
      print(f"SunSaturn# [FAIL] : Victron read bad data: {e}")
      exit(1) #exit program no point doing anything
   try:
      float(device.battery_volts)
   except Exception as e:
      print(f"SunSaturn# [FAIL] : Return type was not a float: {e}")
      exit(1) #exit program no point doing anything
   if not device.battery_volts > 0:
      print(f"SunSaturn# [FAIL] : Voltage not greater than 0!")
      exit(1) #exit program no point doing anything
   #print(dir(device))
   #print(type(device.battery_volts))
   return device.battery_volts


#http://ha:8123/api/states/switch.kasa_smart_wi_fi_plug
#http://ha:8123/api/services/switch/turn_on
#http://ha:8123/api/services/switch/turn_off
def plug(address,token,entity,state):
   #returns on/off with "state=check" else 1
   if state == "on":
      url = "http://" + address + "/api/services/switch/turn_on"
      req = "requests.post(url, headers=headers, json=data)"
   elif state == "off":
      url = "http://" + address + "/api/services/switch/turn_off"
      req = "requests.post(url, headers=headers, json=data)"
   elif state == "check":
      url = "http://" + address + "/api/states/" + entity
      req = "requests.get(url, headers=headers)"
   else:
      print(f"SunSaturn# [FAIL] : Only off/on/check should be called")
      exit(1) #exit program no point doing anything
   #print(f"url is {url}")
   #print(f"req is {req}")
   data = {"entity_id": entity}
   #print(data['entity_id'])
   headers = {
      "Authorization": "Bearer "+ token,
      "content-type": "application/json",
   }
   try:
      response = eval(req)
   except Exception as e:
      print(f"SunSaturn# [FAIL] : Failed connect to home assistant: {e}")
      exit(1) #exit program no point doing anything   
   if not response.ok:
      print(f"SunSaturn# [FAIL] : Failed response code not 200: {response.text}")
      exit(1) #exit program no point doing anything
   check = json.loads(response.text)
   if state == "check":
      check = json.loads(response.text)
      return check['state']
   return 1


#CONFIG - EDIT ME
#######################
#HOME ASSISTANT
#HA assistant token
address='ha:8123'                     #Home Assistant API [IP:PORT]
                                      #HA token, create one in HA
token='eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiIyYmQ1MDM0YTg2NjY0NDIzOWZlZjg2NmZiNGY4N2E1MyIsImlhdCI6MTcwMTk5MTU3OCwiZXhwIjoyMDE3MzUxNTc4fQ.swUTIoUFWbXEul3JuWRRiKpE-Ene-kKeM1ch8uNQF5o'
entity='switch.kasa_smart_wi_fi_plug' #grab entity of Grid Plug from settings for device on homepage of HA
#VICTRON
voltage_max=26.1                      #we don't want voltage higher than this for morning solar charging
serial_port='/dev/cuaU0'              #serial_port for VEDIRECT, on linux try "setserial -g /dev/ttyUSB[01]" to find your serial port
serial_baud='19200'                   #serial baud rate, 19200 seems recommended setting from Victron
#######################

#check voltage of battery
volts=victron(serial_port,serial_baud) #will exit program if any failures with exit(1)
#print(f"Volts is: {volts} ",type(volts))

#check if plug is on or off
check = plug(address,token,entity,"check") #last arguement can be 1 of on/off/check
print(f"Battery voltage is {volts}, checking what to do...")

if check == "on":
   #plug is on, check it we need to turn it off
   if volts > voltage_max:
      plug(address,token,entity,"off")
      print(f"Voltage is greater than {voltage_max} Turned off Grid Plug")
   else:
      print(f"Grid Plug is on and voltage less than {voltage_max} DOING NOTHING")
else:
   #plug is off, check it we need to turn it on
   if volts < voltage_max:
      plug(address,token,entity,"on")
      print(f"Voltage is less than {voltage_max} Turned on Grid Plug")
   else:
      print(f"Grid Plug is off and voltage greater than {voltage_max} DOING NOTHING")

Again we reuse the Home Assistant function, but add an extra function for Victron to pull battery voltage off the solar charge controller. New config options are max_voltage we figured out earlier, and serial_port and serial_baud rate. Adjust these to work with your setup. So what we are doing is checking if plug is on or off first, then depending on that we check voltage against voltage_max to decide to turn the plug on or off. Pretty simple πŸ™‚

Now we are almost done….Personally I do everything as root(you may need to so you can access serial port), so I created a /root/cronjobs directory and stuck victron.py and ha_grid_on.py in there. Last thing to do is toss them in cron: “crontab -e”

# run every 15 minutes between 11pm and 6:59 am, suppress logging
*/15 23 * * * (/root/cronjobs/victron.py) > /dev/null 2>&1
*/15 0-6 * * * (/root/cronjobs/victron.py) > /dev/null 2>&1
#make sure grid plug on no matter what by 7am
0 7 * * * (/root/cronjobs/ha_grid_on.py) > /dev/null 2>&1

And don’t forget to “chmod 700 *.py” πŸ™‚

Keep in mind you have to accommodate for “voltage rebound”, this happens when no load is present, battery voltage will jump up .3-.4, so you will want to lower your voltage for day πŸ™‚ Unfortunately this means every 5 min its on solar, every 5 min on grid because of the voltage rebound. To compensate I use to run cron every 5 minutes, now I run every 15 minutes, long as not running a really high load should be fine.

And that’s it, all automated, never worry about it again πŸ™‚ Of course adjust $max_voltage come summertime, but other than that, your golden πŸ™‚ I’ll leave adjusting python script to actually use different max_voltages depending on the month as an exercise to the reader….

Till next time ….

SunSaturn

Batteries Lifepo4 – Lithium Iron Phosphate upgrade and why

The past setup:

Well my two marine batteries died I had used as a backup for servers. What I had done for my servers at home was modified a UPS and hooked up two 100ah marine batteries in parallel for 200ah of capacity. While this was a great cheap solution at the time, 2 marine batteries were 100 dollars each and a modified UPS to run off them was a great idea at the time.

New tech in batteries – LifePo4(Lithium Iron Phosphate)

I was using alkaline 12V batteries that long ago, but now with the new contender on the market Lifepo4, short for Lithium Iron Phosphate we really need to look at why they are so much better for our homes than the old alkaline batteries. I had to watch countless YouTube videos on electrical engineering to get to bottom of this. To basically sum it up, let’s say we have one 12 volt car battery at 100ah(amp hours), and we have one 12 volt 100ah Lifepo4 battery. Alkaline batteries need to be charged once they reach 50% capacity, Lifepo4 batteries can be completely discharged and still run loads needed.

The recommendation is to charge Lifepov4 batteries by time it hits 20% so you don’t drain it completely. Also alkaline batteries die after about 500 cycles, where the new Lifepov4 standard can last as long as 6000 cycles! So I have found Lifepov4 batteries will not only last you longer, but you can use them longer before they are completely discharged, and for an added bonus, they are safe in your house because they won’t cause fires like other batteries will!

This basically all means then a 200ah alkaline battery would equal the performance of capacity of a 100ah Lifepov4 battery, and will last longer, not only 500 cycles! Definitely then worth twice the cost of an alkaline battery.

Current pricing of Lifepov4:

Alright that is all nice and all, but let’s look at real world prices of replacing my alkaline 200ah setup. The current best priced 100ah Lifepov4 battery on amazon is:

This one

WOW $570 + tax CDN@!!! So what $650 CDN just for a 100ah battery! And this gets worse as we go to 200ah batteries at 1k or more, and 300ah batteries at nearly 2k it seems! Ok this is completely unacceptable, we are being robbed in the USA and Canada on these China made cells in these, what if we build our own?

What are current stats and prices from China?:

Checkout following link from reputable supplier in China on Alibaba:

https://szluyuan.en.alibaba.com/productgrouplist-916502401/Non_grade_A_lifepo4_battery.html?spm=a2700.shop_co.88.17

The forum thread for her where people had good experiences is here:

https://diysolarforum.com/threads/where-to-buy-from-these-days.43265/

China sells them by the cell at 3.4 volts and a certain amount of AH(amp hours) for each cell. So a quick lesson in electrical engineering is in order to understand some of this. There are two ways to hookup batteries to each other, in series or in parallel. So if we had 4 of these 3.4 volt China cells in series, you add the voltage together and the amp hours stay the same. So in this case if we took 4 of these and connected them all together we would have the 12 volt battery we need. If we instead hooked them up in parallel, the volts stay the same but the amp hours increase. So in parallel we would only have 3.4 volts, not what we want. We want to start at a 12 volt battery and get the most AH for our money.

So what we need is 4 of these cells to build a 12 volt battery, then in future we can build another one and hook those two up in parallel to increase capacity if we want. For series connection all we do is hook each battery up negative to positive with cables, for parallel all we do is hookup terminals on each battery negative to negative and positive to positive with cables or bus bars, whatever you prefer, easy enough right? China supplies bus bars generally so we good there, we don’t have to go off and buy 2 gauge cables off Amazon or anything.

Another quick lesson, the total Power of a battery would always be the formula:

Watts = Volts x Amps , so to get any of those values all we need is 2 of them: ie: to get amps knowing watts and volts, we would just do watts/volts=amps and so on.

Grade A vs Grade B cells from China:

People all over the internet will argue over Grade A vs Grade B EVE cells, basically Grade A someone put in the effort to fully test them, discharge and charge and will charge you double for that. With Grade B they do same tests, but don’t go through effort of fully discharging and charging them, but it is from same production line, so for cost effectiveness we want to go with Grade B obviously and take our chances. They should all be same volts when we get them, only thing they didn’t test what capacity with fully charging and discharging them, so that means we could get a better battery to lol. So if it is for home use, use Grade B for price alone, if for a business go for Grade A.

Let’s pick a cell from China:

If you look at that Alibaba webpage from above, we know Amy is reputable, may take us two months to get our batteries, but cost wise it will be better. Let’s take a quote from the forum link above about someone’s experience:

 “I placed my order of 4 x EVE LF280K with Amy on June 7th. Shipment was two boxes (2 batteries per box) and box#1 arrived July 28th and box#2 followed the next day on July 29th (52 days delivery time to Toronto Canada).

The cells were described by Amy as “LF280K, brand new. Grade B β€”the voltage and internal resistance are matched, the capacity is not. The actual capacity is 275AH-284AH. QR code has B stamp , $111/pcs”.

Shipping was $140 and final delivery made via UPS. Tracking number was provided when order was placed, but package could not be tracked until it arrived in Canada (by sea).

Transaction was super smooth and went without a hitch. Thanks to members of this forum for recommending Amy as a reliable and trustworthy source. Will definitely order from her again.

I’m a degenerate gambler, so I’m looking forward to running capacity tests on each cell to see if I got a good batch or not “

Wow he paid a mere $650 CDN total for a 280AH battery! That would cost us 2k on amazon or anywhere else!

Is that all or do we need more?:

Technically you could just do that and be fine but there are actually two more things needed for a Lifepov4 battery: a BMS and a charger.

A BMS(Battery management system) is a card you buy online that has little wires hooked up to all the battery terminals, think of it as something that protects the battery from overcharging, over discharging, temperature cutoffs and so forth, it is basically a good thing to put on the battery. They run cheap crappy ones, and hundred or 2 for the good ones that even come with a Bluetooth app for your phone giving you all detailed stats about your new Lifepov4 battery you put together. It is a good idea and would recommend it. Last thing we need is a charger meant for Lifepov4, and we are set.

In all honesty, I think a good quality BMS, charger, and perhaps a box to put the battery in when your finished is a good idea. If BMS dies, charger dies, or battery cell dies, it’s as easy as just pulling it out and replacing it, unlike a normal battery where they put so much glue and stuff on it to prevent you from opening it that you’d have to toss the whole thing out.

Putting it all together:

Ok this is definitely not the faint of heart, in order to now change our setup from modified UPS using 2 alkaline batteries we have to rethink our whole setup for Lifepo4. So the UPS will need to be removed, we will need the following in CDN dollars:(take off 25% if USD)

  • a) Inverter(1500 watts or more) $400
  • b) Automatic Transfer Switch $200
  • c) 280 AH Lifepov4 battery $650-800 + $2-300 for BMS card and charger

So is it even worth it? Our upfront costs are already $1500-2k to replace our simple setup, why not just go to Costco and pay $400 for 2 more batteries that will die on us again. Also why not just get a UPS that supports Lifepov4 instead of going inverter/transfer switch route.

Here is why, a UPS that supports lifepov4 is very expensive, I believe Tripp Lite makes one, I think their top model supports around 750 watts and your going to pay 1k for something that can’t even handle a microwave oven or many servers running at same time? What if the power grid goes out, I would definitely need to be able to run around 1000 watts safely for servers, routers, internet, TV etc in livingroom. Of course you could get a top of the line one that supports more, but then your paying thousands for a rackmount option, not worth it.

How about we keep our inverter separate from rest of system that way we can upgrade it anytime we want, also add more lifepov4 batteries in parallel in the future if we want more capacity. This one 12V battery at 280 AH is like 6 alkaline batteries in parallel and is lighter to boot! $200 a piece from Costco = $1200 in alkaline batteries that would just die on you again!

Keep in mind we will stay 12V with our 1500 watt inverter or even a 2000 watt inverter, it is only when you start scaling up to 3000 watt inverters we would have to start scaling our batteries to 24V or even 48V if you wanted to run a whole house.

I left the best thing for last:

This new setup would allow you to do so much more, we could toss in a solar charge controller for a couple hundred dollars and some used solar panels after to the mix, and get free energy now if we wanted. We could switch our our automatic transfer switch to use the batteries when they are full from solar energy, and switch back when our batteries hit 20% discharge! I bet that sounds like fun, paying less in electricity bills just because you did a proper setup. Also you can check battery status from your phone at all times vs buying one off amazon that includes nothing!

Let’s get to some links for our parts list already!:

a) Inverter:

https://www.voltworks.cc/collections/used-products

Let’s start with 1500 watt inverter, this will be cheapest we will find for good quality, even if we go new still be cheaper than amazon. There are cheaper 1200 watt inverters on amazon, but I’d feel more comfortable with 1500 watts. If you have a lot of money go with an expertpower expensive inverter, they have transfer switch and charger built into them already, but I don’t think it’s worth it, what if your inverter dies, that is an expensive replacement then, but if money is no issue get a 3000 watt inverter from them. Why did I pick this one? Because you find a 1500 watt inverter with a pure sine wave not modified sine wave(the former protects your electronics) for a better price and quality parts πŸ™‚

b) Automatic Transfer Switch:

This will allow us to use the grid and switch to inverter batteries if grid goes down on us so our servers/PC’s stay on and whatever else you want for up to 1500 watts of the inverter we picked. Keep in mind on this you have to change a jumper setting for an instant switch as it’s set for a generator with a time delay when you get it. Also they have a pre-wired version so you don’t have to hack up extension cords if you choose on US amazon site. I believe this one will support up to a 2000 watt inverter, they have a 50 amp version as well.

This is just a smart choice, if our inverter ever dies or we want to upgrade to 2000 watts, it is a quick swap out, and we don’t have to pay for an expensive inverter with a transfer switch already built it saving us money again. For reference $300CDN vs $7-800 is a big deal especially it it dies one day, I’d rather put that money towards an inverter that has more watts.

c) Lifepov4 280 AH battery cells:

https://www.alibaba.com/product-detail/Luyuan-4pcs-280AH-LiFePO4-LFP-3_62583909993.html?spm=a2700.shop_plgr.41413.33.3b044a44HTxwRK

Talk to Amy on Alibaba about some Grade B cells, also explore her links maybe get a JBD BMS(I hear the overkill BMS is just that one anyways) and a battery box to put everything in. Lot’s of YouTube videos showing how to hookup BMS to these cells, pick one you like, preferably with a phone app, treat yourself here.

What if you want to expand the setup to solar?

Swap out the Automatic Transfer Switch above with this instead:

Then get yourself a solar controller charger(stick to one with same watts as your inverter) and some used solar panels your good to go! This thing will feed off your batteries when solar has charged them up, then switch back to grid when your batteries are low. Free energy, why not put the battery you built to use πŸ™‚

I’ll add more links and information to this setup once I get all these parts, but this is how I would go about it for best setup for your home. Start small with 1500 watt inverter, scale up as needed, maybe one day you want to run your fridge, deepfreeze and air conditioner as well, that would be a good time to scale up to say a 3000 watt inverter and solar charge controller.

I would recommend you build your own battery with BMS and try a setup like this, not only will you be happier in the end, not just the cost savings, just the pure knowledge you will gain from learning how to set it all up from YouTube videos will make you a much better person going green but at same time give you the confidence to go completely off grid one day if you choose, that knowledge is invaluable.

Until next time….

Dan.