Midnite Auto EQ

plongson
plongson Solar Expert Posts: 115 ✭✭
What do you guys think of the new AUTO EQ function on the Midnite Classic software. Is it something you would use or do you like to be in full control of your equalizing? Right now I'm a bit reluctant to hand that duty over to the controller, but what the heck...it has all the duty's now.

Paul
3500w solar, 800AH with Rolls Surrette, Magnum inverter, Midnite charge controller, Kubota 21kW diesel genset...private well...and just recently connected to city power for additional options...nice to have options 

Comments

  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    Re: Midnite Auto EQ

    Paul,

    Personally, I still do only manual EQs. I would like to be invlolved in the decision of when, how long, and at what voltage to EQ. Some of this is a bit of a hold-over from running OB MX-60s, which did not have a temp compensated EQ voltage (at least for a stand-alone CC).

    Some of this desire is from my being a "Green Visor" type of person. In a similar fashion, personally do not like the concept of Auto Gen Start functions.

    Both of the above can be made to work well without human intervention, BUT, would I much rather do them manually. These things are very much a personal choice, but the time to EQ is often driven by measuring the spread of manually taken SG measurments, and the end of EQ is often driven by monitoring the change in this spread and perhaps (rarely) monitoring the temp rise of the bank during EQ and so on. Good question, YMMV. Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: Midnite Auto EQ

    Paul, remember where you are at on that 'new' learning curve, your call...

    HTH
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • SolaRevolution
    SolaRevolution Solar Expert Posts: 410 ✭✭
    Re: Midnite Auto EQ
    Vic wrote: »
    Personally, I still do only manual EQs. I would like to be invlolved in the decision of when, how long, and at what voltage to EQ....
    ...Some of this desire is from my being a "Green Visor" type of person. In a similar fashion, personally do not like the concept of Auto Gen Start functions...

    Both of the above can be made to work well without human intervention, BUT, would I much rather do them manually.

    I agree with the preference to perform EQs and auto gen starts manually. If the operator can really grasp the concept I give them as much info as I can and let them decide. The problem comes with systems which do not have diligent operators to watch after them. If they just cannot grasp the concepts, I have been setting auto EQs at the lower end of the recommended voltage and time range and suggest they have me check on things annually. The auto generator settings I use differ drastically based on the individual system and projected usage paterns.
  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Midnite Auto EQ

    I think each Manufacturer has different meaning of EQ and Auto EQ. The term is pretty fast and loose. I am always leery of a product that has the ability to raise the voltage to a level that could do major damage to a bank of batteries. A Lot chargers just mean they will increase the voltage to a Bulk level every so many days and finish off a adsorb and return to Float, most do not have the ability to ever reach a true EQ voltage. Then there are Charge Controller's and Inverter Chargers that can reach a voltage on a unattended Bank that are not only dangerous to the Bank, but your property and life in my opinion.

    I posted today about Heart Interface Inverter algorithm that would do a full EQ for 8 Hours once initiated @ 15.2 Volts or 30.4 volts, while it was manual, if you set it and left it unattended it would boil a set of batteries dry.

    Sometimes you have to ask yourself if you have a number of life cycles in a battery, what is the trade off between efficiency and cost of opportunity charging a battery. Once a week or so may be ok for a normal charge cycle and efficient to do to keep the electrolyte mixed. Heavy repeated EQ cycles at True EQ voltage will definitely add to positive grid corrosion.
  • plongson
    plongson Solar Expert Posts: 115 ✭✭
    Re: Midnite Auto EQ

    Well, My initial thought was and still is...I want to be in control of my EQ. Given what I know about the process and what I have experienced performing them a few times, it's not something I'm going to relinquish. Is a time based EQ even the correct way to condition a well maintained battery bank? What do you guys use as a guideline to EQ? Falling gravity levels?

    To get my gravity up (remember I had trouble with it being too low, 1.225) I went to 59vdc absorb for 3 hours. 59vdc is damn near a EQ every day! Now I have a pretty consistent 1.260 to 1.275 at the end of a good sun day. I'm kinda getting off on another subject, but do you think there is a point where I could back off on the volts/time?? Water usage has not been bad...

    I'm a "green visor" big time as well. LOL I'm committed to making these batteries last as long as possible.

    Paul
    3500w solar, 800AH with Rolls Surrette, Magnum inverter, Midnite charge controller, Kubota 21kW diesel genset...private well...and just recently connected to city power for additional options...nice to have options 
  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    Re: Midnite Auto EQ

    Paul,

    First, it is good that you sport that green visor. Paying attention to your batteries is really the most important thing one can do IMHO. You noticed that your SGs were lagging, and took action quickly, and got the result that you were looking for.

    I believe that you have downloaded the Surrette Solar Battery Manual, but just in case:
    http://www.rollsbattery.com/files/userfiles/SolarBatteryManual.pdf

    It is generally recommended by Surrette to EQ every 60 - 180 days, depending on average DOD and general battery health. Historically, they have been very specific that the MINIMUM EQ voltage is 61.9 volts on a 48 V bank. Their recommended duration is 2-3 hours (IIRC), and to use the lower range of EQ voltages unless the user is trying to address wider than normal SG variations or other issues.

    It is my opinion that the EQ voltage should be temperature compensated. And you know that the largest amount of Hydrogen gas is generated at the highest charge voltages, so am certain that you will allow for good air circualtion to the outdoors during EQs.

    Re 59 V Asorb, it is quite possible that as the days get longer, you could well reduce this. 59 volts on this battery might be considered as an Opportunity Charge voltage, which is often used in the Winter to get as much charge into the batts on short days. If you have been using fixed Asorb time (as opposed to Return Amps), that you will see the SGs creep up with the lengthening days of Spring, unless 59 volts is what this bank, with your useage requires. Higher water constuption is also a good indication that the Asorb V should be reduced. And, 59 volts is quite a long way from and EQ voltage for these batteries IMHO.
    Good Luck, Enjoy Spring, Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • plongson
    plongson Solar Expert Posts: 115 ✭✭
    Re: Midnite Auto EQ

    Hey Vic, Thanks!

    Actually I was being just a bit sarcastic saying 59 was close to EQ voltage. It's strange how humor can't travel over the internet...LOL

    Paul
    :D
    3500w solar, 800AH with Rolls Surrette, Magnum inverter, Midnite charge controller, Kubota 21kW diesel genset...private well...and just recently connected to city power for additional options...nice to have options 
  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    Re: Midnite Auto EQ
    plongson wrote: »
    What do you guys think of the new AUTO EQ function on the Midnite Classic software.

    Personally, I like it. I have three Classic 150's, two on wind turbines and one on solar. I have the wind Classics set to ridiculously high absorb and float settings to keep the controller from unloading the turbines and letting them run up against the clipper. I'm using Waste Not Hi mode in the solar Classic to turn on a 2 kW water heater element (240 volt) when the controller allows the voltage to rise 0.1 volts above the charge state set point. This extra load keeps the panels throttled up and uses excess power from the wind turbines during absorb and float, except in really windy conditions where they'll push the bank up to 31.0 volts (temp compensated) before the controllers start to cut them back.

    Otherwise I have the solar Classic set to do a lower voltage equalization once every 14 days @ 30.0 volts (temp compensated) for one hour, which is .5 volts above the normal absorb voltage. I have Surrette batteries and they don't seem to mind these higher voltages. The auto-equalization at 30 volts once every two weeks has, so far, eliminated the need to manually equalize with the generator.

    I have a chart hanging on the wall in my utility room with the settings in the Classics on it so I can remember what they're supposed to be.
    Attachment not found.

    So far this has been working OK for me. I'm not comfortable doing a full voltage equalization without supervision since equalization is not a thing that can be timed. When the SG stops rising in individual cells equalization is done, and extending it beyond that is hard on your batteries. But the lower voltage equalization that I'm doing once every two weeks automatically, so far, hasn't seemed to hurt anything. And the bank performance has been such that doing a manual equalization at full voltage has been unnecessary.

    Just from here.
    --
    Chris