Apparently an absorb cycle "wasn't needed" today.

morpho
morpho Solar Expert Posts: 176 ✭✭✭
Hi,
endless fun.
So we have just come off 2 weeks of no sun and I was really looking forward to letting the sun do the work today. Unfortunately, I had to leave the old homestead for a few hours this morning.
I came back expecting the system to be well into the absorb cycle. 
It said float...that seemed odd. I check the absorb time logged: 0
Float: 1 hour and change.
I check the SG's are in the 1.225 - 1.3 kind of area.

So I force bulk. It flips over into absorb right away and the clock is counting down my absorb cycle.

Any ideas what the heck happened?

Cheers
11.5 kw array  -  3 - midnite solar classic 200's   -  Magnum MS-PAE Inverter  -  Magnum ME-RC50 remote  -  ME-BMK batt-monitor  -  8 DEKA Solar GC15 230amp hour (48v) - Yamaha ef3000ise - 1 confused look on face

Comments

  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    Time to do an equalization perhaps? 2 weeks of no sun is not a good thing, were there any loads? A battery may have the voltage but when a load is placed on them, the voltage collapses, so the CC may see the battery at full charge when in fact it is not. The SG readings would indicate a weak battery but not a dead one, my suggestion is to equalize, one opinion, others may vary.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • morpho
    morpho Solar Expert Posts: 176 ✭✭✭
    Hey mcgivor,

    I'm not sure if there was much of a load on it as I was away when it happened, but short of the cat growing thumbs and using the hair dryer behind our backs, the biggest load would be the fridge. 
    It would seem odd that the cc wouldn't have even tried for the absorb cycle. It usually kicks on around 95% soc and runs through the cycle for 4 hours.

    I also think I am due for an EQ...but for the life of me I can't get it to a state of fully charged so I can do it. I can run the genset to bulk charge it...I can even run it through the whole Absorb cycle...or at least the generators version of the cycle. I shut off the generator and the PV system says bulk charging and there just isn't enough light to get up that hill...nevermind the PV's 4 hours of absorb. Then I would have to run the EQ on it with the generator.

    ...is it spring yet?
    11.5 kw array  -  3 - midnite solar classic 200's   -  Magnum MS-PAE Inverter  -  Magnum ME-RC50 remote  -  ME-BMK batt-monitor  -  8 DEKA Solar GC15 230amp hour (48v) - Yamaha ef3000ise - 1 confused look on face
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    Sorry about your lack of sun, asked the question about load as this would/should bring the voltage down and prompt a bulk. An equalization will force a bulk charge until the voltage is satisfied,  then take it beyond, at least my controller will, so if your generator can provide an EQ, that's what I would do. Personally I have no need for a generator as my bulk is complete usually by 9 am unless it's overcast ,then it may be noon, so my experience using generators is limited. 

    Have you been through a winter before without problems, or is this the first?




    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • morpho
    morpho Solar Expert Posts: 176 ✭✭✭
    I have had nothing but problems with my batteries!
    Both sets! hahaha...

    I am on training set number 2. The first set gave me 5 years of life before they had to be replaced. I have never been happy with the batteries. It seems no matter what I do I have individual cells that are lower than others in the same battery and always a variance between all 8 of the batts. I've logged SG's and watered and EQ'd and cleaned the tops and checked em and I am not ashamed to say I may have even talked to them in hushed tones on occasion. Still no joy.

    I have kind of settled into the belief that batteries suck and that's just the way it is!

    This has been the longest stretch of darkness we have had in almost 7 years off grid. Normally I am blessed with sun even in the winter. Not that I am unfamiliar with having to run the generator, but it is usually way less than more. I am already halfway through my total hours last year and we still have three months left before I can expect to see the light at the end of the tunnel.

    So, I will EQ them and see where I get.

    Thanks again.







    11.5 kw array  -  3 - midnite solar classic 200's   -  Magnum MS-PAE Inverter  -  Magnum ME-RC50 remote  -  ME-BMK batt-monitor  -  8 DEKA Solar GC15 230amp hour (48v) - Yamaha ef3000ise - 1 confused look on face
  • jonr
    jonr Solar Expert Posts: 1,386 ✭✭✭✭
    > always a variance between all 8 of the batts

    You can add a balancer like a HA02 to reduce this.

    I am available for custom hardware/firmware development

  • morpho
    morpho Solar Expert Posts: 176 ✭✭✭
    more cool doodads to add to my wall of electronics!
    11.5 kw array  -  3 - midnite solar classic 200's   -  Magnum MS-PAE Inverter  -  Magnum ME-RC50 remote  -  ME-BMK batt-monitor  -  8 DEKA Solar GC15 230amp hour (48v) - Yamaha ef3000ise - 1 confused look on face