Diy Tesla Powerwall ep51 48v Ups 24hr Test Run Update

[@josephgkrestan3044]

Your out-takes at the end of your videos are always worth watching. Joe

[@AveRage_Joe]

Lol Thanks, that was the Wifey's Idea!😆

[@philipx2]

Traditionally these things charge those 7ah and 12ah sealed lead acid batts. You may have to figure out how your lithium packs compare to what it thinks it has and then pick the number of packs the is closest to your number you get. Just a thought. Good Luck.

[@AveRage_Joe]

Since I changed the setting for battery packs installed to 99, it says 52.9v is now 58% battery left. That might of fixed my issue. So Ill do some more testing and update on progress.

[@KSSilenceAU]

Official maximum is 10, set higher and the unit may behave funny, depends how the programming handles it.

[@mobilesigngeek1693]

What software package did you use to put the pointy hand thing that was pointing towards your cat playing with plastic?

[@korishan]

Ok, there are some good comments. However, here's what I think: As philipx2 said about the batteries being at 12aH, that's what comes with the system. Then it has 2 Batteries / Pack, and 4 packs. So, that gives you 8 batteries @ 96aH as the batteries are in a 4s2p configuration (We have to remember that these batteries are at 12V nominal, not 3.7V). Your 100W bulb pulled about 1A. So, it 'should' have ran for about 4 days. But, the UPS was also running and that was drawing at least 2A (only guessing based on when you plugged the UPS into mains thru the Wattmeter). So that gives you ~3A total draw from the pack. 96/3 = 32Hrs. Still seems like it didn't run long enough, unless your starting voltage wasn't at full capacity. If the UPS was pulling closer to 3A, then it'd been 96/4 = 24Hrs. Sounds like when the UPS is on battery power, it draws closer to 4Amps. Here's a thought! (uh oh!). Take a Ammeter and connect it to the batter side of the input and see how much the system draws without load, and then with load. Try loads of 100W bulb, 300W dryer (or what ever), 1000W microwave. Verify the output wattage using the wattmeter for the loads. This will give you the most accurate readings as to what the UPS uses under varying conditions. Aaaannnnddd, another great video! :) Thanks for the updates on the progress on these units. Gives loads of information for those of us who plan to use these for our Inverters

[@AveRage_Joe]

Yeah I plan on using an ammeter on the batteries, think I have another digital one somewhere. Its hard to say exactly what its thinking and or what its doing. Ill definitely be trying a few different loads and see what it DOOOOO.

[@alcus440]

Hi AveRage JoeI run 13S. Only as an inverter. I never plug it into the wall. I never run PowerChute as it is not required and just adds a ton of confusion.13S provides a range of 39V to 54.6V (3.0V to 4.2V). APC will shut down on its own somewhere around 40V (+-40V for 48V APC, +-20V for 24V APC and +-10V for 12 APC). If your cells are not well bottom balanced, one or more packs may drop well below 3.0V so keep a close eye on that but they should not stay there long as the total voltage will quickly drop below 40V and the system will shut off. If in good working condition.I chose not to go with 14S as at 54.6V the cell voltages are 3.8V or far from full capacity. If you fully charge them, the APC should not even start up due to high voltage test fail.Plugged into the wall will likely result in one or more packs exceeding 4.2V so I would not leave it plugged in for too long and never unattended without watching all pack voltages. Your pack is certainly large enough to withstand the current provided :) Also, since lead acid charging systems maintain a float charge, which is not a good idea for lithium (very dangerous), it would great if that could be turned off. If anyone knows how to do that, please share. I've heard that it might be possible and plan to look into it at some time.PowerChute is really nice, when properly configured, if you want your computer to shut down automatically,... I got over that many years ago. I only use it if I want to turn off the beeping alarm, other settings and then never run it again. The APC UPS knows what to do without PowerChute running.YES!!! Turning on your laptop with: the communication port plugged in, PowerChute likely configured by default to start running, PowerChute improperly configured,... PowerChute shut down your laptop and then the APC. It could not wait to do it and mess with you and your test!!! I felt for you buddy!Your test would have run fine if you had not started PowerChute or if you had disconnected the communication port before starting your laptop. I hope you run that test again to completion. Your cat believes in you :)PS - Great videos. Thanks for sharing. Will stay tuned.

[@AveRage_Joe]

Cool, ya I mainly wanted to turn off the beeping and possible monitoring later. It didnt have a problem starting up on battery at the higher voltage which is good for me or at least for now. If it continues to start up at that voltage then Ill keep 14s. Just a little less in the conversion. I figured as much for it shutting down on me lol. I guess its part of the learning process. If I ever find any info on the charging circuit Ill pass the info along as it would be some valuable info for the Lithium Ion community. Thanks again!

[@KSSilenceAU]

my SUA2200RMXLI3U will cut off at around 40-43v depending on load, higher the load, the lower voltage it will go down to before it cuts off (programmed that way i presume because of the characteristics of lead acid batteries). charging wise they sit around ~54.5v on a float style charge.

[@alcus440]

I concur. At low draw mine shuts down at 42.0V. At higher draw, the cut off is lower but it is dropping quite fast at that point and the voltage bounces back up quite quickly on the lithiums once it shuts off. Float charge on mine is 54.8V (not that I plug it in with lithium attached). I'll likely be dropping to 12S soon as that will provide more of a low voltage safety margin (+-3.5V which should be about 5% remaining capacity). Bottom balanced at 3.0V and charging without balancing should work out pretty well. Time will tell.

[@Aastan]

Logically, the system parameters are based on the original battery capacity. The number of packs that you set should be base on you parallel pack size based on the original batteries in amp hours to determine the correct number to set so that all other readings presented by the PowerChute are close to accurate as possible. Also, run the Calibration test in the PowerChute.

[@AveRage_Joe]

+Aastan Yeppers, Im am thinking the samzies! Ill do that test once I get some solar hooked up 😀

[@Aastan]

By the way, leave the pack at 14S. This accounts for the voltage curve. Safe operating range, for new LI cells, would be 3.0V-4.1V for longevity. At the 3.0V low end that is 42V, conversely, that is 39V for 13S. LA batteries will read about ~51V when full and about 48V when discharged 50%. At 44V they are completely empty, 13S puts you outside the curve and will probably give false readings in the PowerChute app.

[@AveRage_Joe]

Oh yeah Im going down in voltage lol. Im sure after I do a self test it will improve

[@pushdaelectrons]

Since this is a server room/closet product, the ACP will put the focus on remaining run time (network/server folks plan on being on the mains all the time and gracefully shutdown the equipment using powerchute when not pulling power from the grid). Your best bets are two fold: 1. Don't run powerchute (you plugged in the brains by plugging into your laptop which shut everything down). The APC will run as long as possible until some preset low (unchangeable?) voltage. There is a free software (albeit horrible interface) called apcupsd (Linux and Windows binaries are available). Use it to monitor voltages and get data. You'll have to disable the shutdown scripts as well (which are only ran on the laptop/computer equipment and not the UPS) though but it won't shutdown the UPS. 2. Execute the run-time calibration tool and compare to the number of packs that the APC thinks it has. Repeat. Many. Times. To. Get. It. Right. I'm attempting the same thing with a smaller 24v APC UPS and ended up hacking the charging circuit (allows a higher charge voltage) and am planning on using an external (to the UPS) small battery monitor which will cut in/out the batteries from the inverter. Powerchute will not be plugged in. No way. I like the idea of using solar cells to charge the batteries but I think you end up having to supply a AC current to the APC (sad face) to 'hack' away around the equipment. If anyone has any deeper APC hacking knowledge, please let me know! I'd rather attack the low voltage threshold built in vs. using an external monitor. Take a look at one of my videos to see apcupsd in action! I think it is in the 'Persuant to UPS Volts' video. (Warning: interface and eye candy pain ahead)

[@AveRage_Joe]

I spent a few hours with another youtuber last night installing and configuring NUT(part of that I was waiting for linux to install). I dont know crap about linux aaaaand since my spelling is crappy, lets just say it took a while LOL. I think I saw that software apcupsd last night. I may try it.

[@emceh]

Run the calibration with load. Those are smart ones, it thinks the battery is empty because original battery pack was way smaller.

[@AveRage_Joe]

Yup thats what I was thinking. What size of load or does it matter I wonder. Ill have to wait until I get some solar hooked up so I can recharge the cells!

[@levik1832]

The issue you are having is what I was wondering with one of my questions in your previous video with respect to the UPS using a hard-coded charging / discharging algorithm. If it was made to work with lead acid batteries, won't it think your batteries are full and empty based on the voltages and recommended discharge rates that are best for lead acid batteries and not Lithium Ion batteries (which obviously have much better profiles - hence why we use them)?

[@AveRage_Joe]

+levik1832 Yeah it will for sure base its info off LA batteries. Ill be trying some different settings with the added battery pack setting to see if I can get it to match more similar to mine.

[@tbbw]

A youtuber called FFcossag used a serial console to connect into the UPS to change the battery charge cutoff and other things. Since you are running non standard batteries you might need to change these settings as well so the UPS knows the correct cutoff voltage and such. The video i'm refering to is this one: Unedited quick blog video (INCLUDING HOW TO SET APC UPS CHARGE VOLTAGE!!1)

[@AveRage_Joe]

+tbbw Ill look up that vid. Thanks!!!

[@bigsmile542]

Darn Cat did it. No other idea

[@AveRage_Joe]

He probly did after he got done checking his catmail 😜

[@skipsteel]

AMC powerchute demands tighter voltage spec's because it is used Lead acid 2-3% just more battery packs to maintain higher tolerance or hack the software to allow 5% degradation. Also whats going on with the inverter?

[@AveRage_Joe]

Ya I just added 99 battery packs in the setting lol. It seems to be working fine? I still need to do the calibration test tho. Ill be doing that here pretty quick!

[@KSSilenceAU]

The Light indication your getting at ~1 minute into the video means the UPS is in sleep mode. no need to power off to reset, just briefly press the on button and it should resume. (Provided the batteries are not flat). when the UPS is sleeping the Network card if installed will stay awake and you can power back up from the Network card or put the unit to sleep from the network card.

[@AveRage_Joe]

Awesome, thanks!!!! Good info to have 👍

[@KSSilenceAU]

Should note if the unit powers down due to low battery, it will snooze with just the single low battery indication flashing for about 10 minutes then May Possibly shut down and go "Braindead" after that depending on how its configured, in which case the network card will also power off, so if you know your gonna run it down to the wire but you need the unit to keep the brains awake, manually put it to sleep before it shuts off and it should then keep the NMC powered until either the batteries hit critical, the sleep timer expires, AC input power returns, or you manually power it back up. In the NMC under Powerchute --> Configuration section you can tell the UPS how it deals with a shutdown as follows: On-Battery Shutdown Behavior: Restart when (AC) power is restored Turn off and stay off and under Configuration --> Power you can set the Maximum sleep timer as such: Duration of Shutdown Sleep Time: hours [0 to 359.9] i have mine set to 72 hours, meaning it will sleep up to 72 hours before it shuts down if the AC Power doesnt come back by then. Obviously it should shutdown totally before then if the batteries get very low. Another thing, these UPS's have an EPO (Emergency power off) connector on the back which can be connected to a Switch or relay contacts and used to instantly "Kill" the UPS, this may be handy as you can wire up a "Kill Switch" or could have some sort of BMS "Kill" the ups if one of the packs voltages hits critically low or high to prevent battery damage. The manual will explain how to wire up the EPO. As for your mention of a Transfer switch, you should be able to get your hands on a rack mount ATS (Automatic Transfer Switch) to handle this for you. APC, Eaton, Chorlide, STS, etc all make rack mount ATS, some of which have network management as well. im using APC and Chloride units for my racks. They can be had for a reasonable price second hand, and usually come in 10 or 16 Amp versions. Couple of other small things about all APC SU / SUA / RT / XL Smart UPS Series units..... DC power is REQUIRED for the unit to turn on, so the unit will not turn on without DC power even if AC is present. Once powered up the unit will stay on without DC supply (though obviously if you yank the plug it will die if no battery power is connected). This is why many people who do not know much about them sometimes get rid of them claiming it wont turn on, 9/10 times its just a case of flat or toast batteries resulting in no DC power available to boot the unit up, regardless of AC input. If you have batteries connected with the unit braindead, and you connect AC power, the unit will wake up partially, and start charging but the display will be blank, and the outlets will remain off until you turn it on via the test button, network card, or serial port. If AC power is connected and ON, you CAN NOT fully power down the unit, to do so you MUST remove AC power, then press and hold the off button for a few seconds until you hear a clunk and the unit goes silent. A gotcha with the serial port: DO NOT use a standard straight through serial cable between the UPS and PC, if you do, and you open a serial session the unit will cut the output and sleep / power off, this is because APC in their infinite wisdom decided to use a nonstandard pinout, and a straight though cable will result in the "shutdown" pin (in "SimpleSignalling" speak) to be pulled then the computer pulls the flow control lines when the session is opened. No you wont damage the unit, but it will catch your attention alright! Serial port settings are 2400,8,N,1 . you can use this to control the unit as well as program some of its variables using the "smart" protocol, Refer to this link which explains the smart protocol, as well as the commands and their behaviour and some warnings: www.apcupsd.com/manual/manual.html#apc-smart-protocol If you have a Smartslot card installed, you can use the serial port to control the card, however some commands or programming may not work with the card installed as the card basically Hijacks the serial port to communicate to the units brains, so if you need to do programming or use a program like APCFIX to do advanced monitoring / programming, you should remove the card temporarily. Need more than 1 Smart slot? Grab an APC AP9600 single slot or AP9604 Triple slot expansion chassis which allows you to add more cards. you can daisy chain these chassis as well to get quite a few slots. just make sure to RTFM about card ordering and limits. Theres plenty of various cards such as network cards, Environmental cards, modem cards, sensor cards, etc etc. Here is quick list to some of the cards you can get: en.wikipedia.org/wiki/APC_Smart-UPS#SmartSlot_card_models If you need to know anything more, drop me a message or reply and il see if i can answer it.

[@AveRage_Joe]

Ok cool, yeah I made a serial cable to connect up to it and I have the usb cable as well. I dont have the network card in it at the moment but may reinstall it when I get it all going how I want it. I like the idea of the kill switch :) Ill have to do that. Thanks for all this info, much appreciated 👍

[@bimmers50e30]

so 12v lead acid batteries are tricky. 12.6 is actually full and sitting (for a while) times 4 = 50.4... 13.2 is also considered float charge. time 4 = 52.8. 14.5v is full charge cutoff on some chargers, times 4 = 58 volts... I'm timesing by 4 because 48volt system so i don't know why that was shutting off. maybe its cut off voltage is some how set high? I have never really messed with that stuff on thoes UPS's i just know that the simple software from APC can't change to much . altho now that i think about it i do think there is a setting for "long runtime" and "preserve battery"

[@AveRage_Joe]

Yeah it was confusing to me also. Im wondering now if the previous batteries were about dead and the ups knows its cycle from the self tests. So Ill be doing one of those self test after I get the solar hooked up so Ill have a way to recharge them. Also adding "99" packs should help a lot.

[@bimmers50e30]

awesome man! keep up the good work :-)

[@AveRage_Joe]

+bimmers50e30 Thank You!!!

[@RalfFFM65]

You might want to go with 13s. It comes closer to a 48V battery

[@korishan]

This 'may' make a difference. Not sure. 12V in 4s configuration: 11.1V - 13.2V; ranges: 44.4V - 52.8V 3.7V in 13s configuration: 3.4V - 4.1V; ranges: 44.2V - 53.3V 3.7V in 14s configuration: 3.4V - 4.1V; ranges: 47.6V - 57.4

[@AveRage_Joe]

Yeah Im not sure on the numbers they use for the batteries but since I changed the battery packs to 99, the % is a lot better.

[@KitKatFresse]

I'm currently building a "small" backup system for my heating pumps using a rather simmilar APC UPS, mine charges to 54,2V on the batteries so I went with 13S giving me 4,15V fully charged, using 14S i'd only charge to 3,85V per cell... Hopefully my UPS isn't as smart, but considdering it still has a rs232 port i'd say I have good chances :)

[@KSSilenceAU]

my SUA2200RMXLI3U will cut off at around 40-43v depending on load, higher the load, the lower voltage it will go down to before it cuts off (programmed that way i presume because of the characteristics of lead acid batteries). charging wise they sit around ~54.5v on a float style charge. If you swapped to using the safer LIFEPO4 rather than LI-ION, you should be safe to leave them connected with the unit charging unattended. The APC Smart UPS's are also known to get along happilly with an external charger no worries.

[@korishan]

Yeah, I figured you could use a charging bms w/o issues as the ups could still detect the soc of the batteries and terminate charge when needed (if "it" is doing the charging, that is). But using an external charger, you could essentially turn off that function of the ups. I'll use the ups to do the charging to start with to do testing and such, and then when I get alternative methods for charging I'll switch over those those. I'm guessing Joe will only charge the batteries from the solar when he gets it all hooked up for prime time :)

[@phizicks]

You will need to do that calibration test. The APCs don't rely on the voltage and calibrate on the capacity of the batteries by draining them and then work out they last over 2-3 years before they pop up with the "replace battery" LED. So do the test and then you'll have to charge them again and the PAC will then know how long it'll last before initiating an alert of battery low etc. meantime, hope everyone gets to see the eclipse, I was stupid enough to come to the USA and not expect the glasses to run out. Aluminium foil or welding glasses anyone-? hehe

[@AveRage_Joe]

+Phizicks Ya ill do the test here soon. Ya solar eclipse, they say #14 min. I got my welding stuff with me to use lol

[@taniksambo1969]

why dont you want to plug the ups into the wall?

[@AveRage_Joe]

Because the charge circuit is designed for lead acid batteries.

[@taniksambo1969]

you didnt have any problems when connecting it to your cells? The video didnt show you did. But im guessing if you leave it on for a long time that it will overcharged the cells?

[@AveRage_Joe]

Nope, didnt have any problems connecting it to the cells. Ive had it plugged in for a few hours with no problems. It will only charge them up to about 54.6v. Ill be charging them up to about 57.4ish with the solar panels once I get them installed.

[@jeffflanagan2814]

Does that ups have a usb port or db9 serial?

[@AveRage_Joe]

+Jeff Flanagan It has both.

[@Oneupthesleevecustoms]

i need to find a ups this big

[@AveRage_Joe]

+One up the sleeve customs Hells yeah!!!

[@Oneupthesleevecustoms]

AveRage Joe and we both need to just video everything we do i hate missing stuff

[@AveRage_Joe]

OMG I know Right LOL

[@mimic58]

hmm 24 hours at 100w Equates to 2.083 amps @ 48v you should of only dragged about 49 AH out of your batteries, there should be stacks Remaining - Got to be the voltage range it UPS is configured for SLA so you may need to up the voltage on the 18650 packs to match , im also asuming those 18650s are at least 3000mah each?

[@AveRage_Joe]

Yep, I just didnt have the ups set up correctly yet. I used 2000-3150 mah cells in the packs!

[@mimic58]

so each of your banks must be what 300-400ah each? Im not sure how many cells you have in them but it looks like at least 100 per bank?

[@AveRage_Joe]

They are 226ah each and Yep, 100 cells per pack!👍

[@mimic58]

Nice - I wish i could get those cells in bulk here in the UK , im having to opt for Powabloc Tubular Gel's more expensive than id like an il only get half that capacity but they do at least offer 1500 cycles at 80% DOD just trying to source 3000xl to go with them :-) out of curiosity how much did it set you back $$$ to build all those packs?

[@kerogre256]

I love all this home made set up but always worry about fire risk, one bad cell can start bad fire... I would put this in fireproof case or something...

[@AveRage_Joe]

Thanks!!! Yeppers, I dont plan on just keeping out and rolly around. Just running some tests ect to make sure its all working 👍

[@MrStemkilla]

each cell is fused. your laptop cells have a higher short circuit risk

[@johnstouchpad6437]

the network card gives more options

[@AveRage_Joe]

Does it?

[@pvdonz8252]

From the look of it ou are using a model SU 2200 or 3000. The good news - these units are not overly complicated, and can be tweaked for purpose. The bad news - you can't change the "low voltage turn off". Changing the number of attached batteries via Powerchute doesn't alter this pre-programmed behaviour. So what's the stat? First of all APC designs use lead-acid batteries. The 2200/3300 with it's 48V battery-pack switches off when +/- 42v on the battery-terminal is reached. Using Li-Ion 14S would thus deplete the cells to 3.0v. 13S would have the UPS switch off with 3.2V remaining. I strongly suggest the 13S solution with used cells. Second charging. That's a big NoNo. The charging circuit is again designed for LA you risk ruining you Li-Ion cells pretty quick. The internal floating voltage circuitry should be disconnected and replaced with an external Li-Ion charger. If you'r interested I'll have a look in the schematics and see what can be done.

[@AveRage_Joe]

+PvD Onz Holy crap if there was a fix for the float charge that would be some great info to share 👍

[@KSSilenceAU]

On some units you can do it in Prog mode via Serial cable by tweaking some of the Calibration Registers like i did to one of my Tower units to correct the float voltage, others can be done with a minor resistor mod to the Circuit board. when doing it via Serial, the unit will still report its ~54v float voltage, but the actual voltage will change, so make use of your multimeter. this could possibly allow you to indirectly adjust the low voltage cutout point too as well possibly as the Prog method just changes the Calibration registers that are used to calibrate what the unit shows vs what the actual is.

[@eliotmansfield]

ups thinks battery is low and tells powerchute to shut your laptop down. I think I deleted or renamed the shutdown.exe command that you will find in the powerchute sw

[@AveRage_Joe]

Thats not a bad idea

[@KSSilenceAU]

If using USB and the OS Native drivers, the UPS shows up as a HID Battery device and in such a case can invoke a shutdown via the standard "low battery" response just like a low laptop battery would. Installing the Powerchute or APCUPSD drivers should stop that and allow you to use software to control behaviour instead.

[@imchris1978]

Did you try apc-fix.com/apcfix software you can use it to change battery parameters just make sure powerchute is not running in the background as it wont connect.

[@AveRage_Joe]

I havent but will now, Thanks!!!

[@KSSilenceAU]

Free version will allow you to view but thats about it. You can contact the author to get a full version that allows you to tweak, otherwise you can use APCUPSD software suite and the APCTEST program it includes to fiddle around.

[@AlexGutierrezPhotography]

Well I am having the same issue, plus when it charges it does not charge the to the capacity of my packs!!! I have a 24v UPS and haven't found anything to fix those 2 little issues. Maybe it has to with the fact that they are Li-Ion instead of PB batteries..not sure what it is yet. but if anyone knows or has any ideas I would like to hear about it!!!!!!!!!!!!!

[@AveRage_Joe]

Since I changed the setting for battery packs installed to 99, it says 52.9v is now 58% battery left. That might of fixed my issue. So Ill do some more testing and update on progress.

[@kuhrd]

The thing to remember with these UPS units is that they were designed with SLA batteries in mind so the charger is going to float charge each 12v battery to 13.5 so 4 of these batteries would be 54V for a full charge. This means that if you are running 14S the max cell voltage for each parallel string of 18650s is 3.85V. The 100% DoD for the SLA batteries is 10.8V so the UPS is likely going to kick out somewhere around 10.8-11.2V per 12v battery. That means a voltage of 43.2-44.8V under load. So each parallel string of 18650s will be seen as dead at 3.08-3.2V. These UPS units will read battery voltage as capacity but they are also looking at the calculated run time based on the number of SLA battery packs.

[@AveRage_Joe]

+kuhrd Awesome! Good info to have. Thanks!

[@davidbland5885]

Puzzling problem.

[@AveRage_Joe]

Indeed, hopefully adding the 99 packs will help it out. Granted Ill have solar hooked up to it and it might not be a problem. But well see!

[@cryidis9818]

AveRage Joe - remember lead only be discharged 50% ish compared to lith . The algorithm will still be lead

[@jamest.5001]

don't turn that ups into a oops!

[@AveRage_Joe]

+James stranger Ive got extras lol

[@james10739]

surely if it says 2% at like 55v or whatever it thinks you have a 5 lead acid batteries and 48 would be 4 i would not have expected it would go bot ways (like a bisexual) but maybe it can and maybe you have to remove or reconfigure your packs for the right voltage

[@AveRage_Joe]

Since I changed the number of packs installed, it says 52.9v is 58% battery left. So Ill do some more testing and update on progress. It could be Bi tho 😆

[@ahaveland]

Classic example of manufacturer trying to make something too simple and failing. If they actually programmed it to do what any sane software would do, it would provide a means of being able to set a low threshold voltage, and then it wouldn't matter how many batteries it has because it would be able to extrapolate remaining run-time based on the rate of discharge.

[@AveRage_Joe]

I know right!!!

[@KSSilenceAU]

Rate of discharge and voltage alone are not accurate enough these days, which is why you can specify how many packs (or packs worth if not using AGM) are connected, this gives the Coarse runtime estimation, and over time when discharged enough the unit will learn and fine tune.

[@davidbland5885]

Puzzling problem.