midnite classic creating 117V at pv input

[boB]

BTW, the newest Classic firmware (2079) will not stay on with zero forward watts (into the battery) for very long.

Perhaps a modbus register could be used to enable/disable this feature
With the LA having a config line to do this?
Or have it disabled if follow-me is not implemented?
Or better still, get charge sharing implemented
And get follow-me implemented over ethernet using an ip-number table on each Classic so that the serial ports can be used for proper applications (inc W10 firmware updates) 

dgd

Did I add a flag bit to choose this ?  Hmmm...  Will have to look.

It doesn't turn off until it sees it sitting there for at least 15 minutes and then just goes to resting...
If the battery voltage is above the set-point, then it will not turn back on.  If the battery voltage is
below the set point, then the Classic will wake up again and start charging.

This was mainly intended so that the Classic would not just sit there and waste energy when there
was no need to be on and running.  Going to Resting will make sure it wakes up only if it needs to
and 15 minutes should be long enough where it doesn't keep clicking on and off.

I will see about adding that enable  flag if I didn't already.

boB

[australsolarier]

ok, so for the people thinking i am mucking about, i hooked up the battery bank (lifepo4 48v/400ah) to the new selectronic 7.5kw inverter. then charged up the battery. the midnite classic went to float and was reversing again. even though i turned on the water tap to trigger the pump. after 5 minutes isolated the midnite, turned it on again  and then normal again. i did not find out how far down i had to discharge the battery for the midnite to volunteer to go into proper float mode.
just wondering how the midnite classic guys are going on with that easy to install windows10 firmware update.

[australsolarier]

ok here more tests:

this morning charged the battery with the selectronic inverter charger. pv panels disconnected at the breaker. midnite classic connected to the battery. after charging finished check the midnite classic. and loh and behold, it was reversing.
then
discharged the battery somewhat and another charge this time with the midnite. went to float, was reversing. hooked up the 2000w kettle to the selectronic inverter and turned on. battery voltage goes slowly down. when it went past the programmed float voltage, in my case 53.6 v, it thought better of reversing and started charging. turned of the kettle: battery voltage rose again with the result of the reversing effect. turned on kettle, normal float.

so the result is in my case between absorb voltage and float voltage it is doing the reversing

might i add here
the midnite classic is not miss behaving because i am "mucking" around.

rather the "mucking" around is a consequence  of trying to figure out what is going on.

i also might add, that this reversing effect is not necessarily a bad thing for the lifepo4 batteries, as they get pulled down to float voltage faster when there is no use of electricity.
however, i am not able to say whether or not this state is good for the midnite classic, as it warms it up to over 48 degrees and the fan turns on.
the midnite classic designers might perhaps let me know whether this reversing state is detrimental to the health of the midnite classic.

thanks for any answer from the more knowledgable people here.

[offgridQLD]

I would see if you could swap the classic another one. That's not normal behavior. As you already know I have a almost identical setup 400ah lithium battery, two classic 150's and a selectronic 6000w inverter.

I don't get the reversing (classic consuming 30w and heating its self up) you are describing at all In the transition period from absorb to float.

Didn't you mention you had a 2nd classic on another12v system. Could you swap that one over and try that one.

Kurt

[australsolarier]

yes i could swap the midnite classics over. however that is about a days work. what with them really small terminals in the midnite classic. the 12v system has 50mm2 cable into the midnite and i crimped reducers on the end so to fit into them really small terminals. they are bent as well. i mean even a 35mm2 wire you have to 50% trimm back to fit into the terminals in the midnite.
plus then reconfigure the settings.

so i think i wait with that experiment till the midnite classic guys come back with an opinion and that new update is available for windows10. then see what's happening afterwards.

[zoneblue]

Just a thought, is your classic float voltage near to or lower than the battery rest voltage? Someone else pointed out that this would cause a quite a lot of reverse potential. What the new firmware does in this situation is a bit unknown becasue if it goes to sleep, then wakes up and repeats it could be interesting.

FTR,  i looked at the 1s monitoring data, and my bank upon float,  reverses for exactly 2 seconds. Then the voltage stablises.

See beta 10 installer here:
http://kb1uas.com/mnsforum/index.php?topic=2794.msg26912#msg26912

[australsolarier]

well yes you want  the float and "rest" voltages to be the same, as recommended by the manufacturer and other people on the fora do.
as mentioned before, the lifepo4's are quite stiff. after changing to float there is some seconds or even minutes  or hours when no use of the battery where it hoovers between absorb and float.

[australsolarier]

so what happens  your agm's drop down to float much faster and even in float might consume some residual power.

basically if i would use 500w or so electricity that reversing would be much shorter also. it's just that my 48volt system is at the moment in the commissioning stage and not connected to the house yet. like i wrote bringing the kettle to boil brings down the battery's voltage fairly quickly and the midnite starts to work in float mode again.
so it is quite possible that there will not be much of a problem when the thing is in use.

[ClassicCrazy]

Yes -seems like you really should try out the newest firmware to see if it fixes your problem. Ryan said though that if for some reason that Beta Windows 10 installer doesn't work, it will leave your Classic without any firmware.
I think he said that using a Windows 7 computer could fix it up  in case Windows 10 beta uploader messed up.

So is it not possible to borrow a Windows 7 laptop ( probably your best option at this point )  from someone to use to install the newest firmware  ? 

Larry

[Halfcrazy]

Yeah so far we have tried the 10 updater on 12 pcs. 1 failed but it also has a couple driver issues. The failure simply leaves the classic with NO firmware so updating with a different pc would work but you have to have the other pc

[australsolarier]

i think i wait till that windows10 updater is secure. the system is not at proper use now. so i can wait. at the moment my new system is just idling. with a socket to tap into the 240 volts. it has yet to be connected up to the house. (the electrician !!!!!!!!!!!!!!!!!!!!!!!!!!!!)

anyway thanks for the helpful answers
urs

[TomW]

Yeah so far we have tried the 10 updater on 12 pcs. 1 failed but it also has a couple driver issues. The failure simply leaves the classic with NO firmware so updating with a different pc would work but you have to have the other pc

Probably sideways of the topic, but...

Just have to ask:


Just wonder if a super basic Linux system  [with the update files] in a USB image that is written to a stick that boots the PC, finds The Classic, installs the update with a python script like the Linux updater does??

Would bypass the seemingly continuing MickeySoft issues?  Probably not all that hard to do.  Might be a very good way to distribute updates? At least should eliminate software issues?

Just been thinking of this as a solution to an ongoing issue with Windows versions.

Tom

[Vic]

ok here more tests:
this morning charged the battery with the selectronic inverter charger. pv panels disconnected at the breaker. midnite classic connected to the battery. after charging finished check the midnite classic. and loh and behold, it was reversing   ...

Hello austral..

You might want to try what almost all of the rest of us do,  when we wish to not have a Classic active  --  We go to the Mode menu for that  Classic,  and switch Mode = Off.

This allows the PV to remain connected,  but the Classic will be in Rest,  until the Mode is again switched to On.

FWIW,   Vic

[australsolarier]

yes i agree if the midnite classic is turned off, it will not do reversing. say your car is using 2 liters of oil for every 100km. it will not use any oil if you turn off the car.  however turning off the car will not result in fixing the problem of loosing oil.

basically what i am saying is my midnite is doing reversing between float and absorb voltages, no matter whether the battery is charged with an outside source or with the midnite itself. then rebooting it will go into proper mode, say resting. until bulk charging again. etc

as far as i am concerned that reversing has something to do with a soft ware glitch.

another thing i like to mention, say you charge the car battery. the charging is finished. you unplug the charger at the mains socket. you  would not expect to be zapped by the prongs of the plug whilst the charger is still connected to the battery.
so this reversing is inherently dangerous. i like to work with the pv wiring when the sun is not shining (at night). because the pv panels do not generate voltage. then you go up the ladder and get zapped. or the bloody wires spark or whatever.
as a matter of fact the midnite should not do reversing at any circumstance. not even if it is faulty. or the rain gets to it. the caterpillar go inside and chew wires. a dust storm. a tsunami. mud wasps build their cocoons inside. etc

say your car is breaking down, the gearbox breaks. you would not expect the car to have 5 reverse gears and only one forward gear, because something is wrong.  or suddenly the brake pedal turns into the accelerator and vice versa.

[ClassicCrazy]

I thiink you have proved your point about the reversing and everyone believes you and Midnite said it is possible and that they made a firmware update to fix it hopefully. So just waiting for you to do that update.