New Battery Time?

basewindow
basewindow Solar Expert Posts: 63 ✭✭
in Off Grid Solar & Battery Systems #1
Hi All,

I've got a query about the batteries at my shack. Per my signature they are:
100Ah Vision 6FM100 Sealed Lead Acid connected in parallel.

I know they are not your ideal Solar Battery, but I got them about 4 years ago before a knew a little more than I do now and they were cheap at 70$ each and 3 years old.

These batteries are I'm guessing getting close to 7 years old now.

They usually get about down to about 85% DOD from the 100% according to the trimetric most nights I'm there. The array normally and easily brings them to 100% each day. I'm usually only there 4-5 days a month so they don't get taxed much at all. The only 24/7 constant load is a 3w fan for the composting toilet.

Recently I was up at my shack and we had 3 days of virtually no sun. In the late afternoon of the 3rd day I noticed the trimetric was reading about 67%. I changed it over to Volts and saw it was sitting at about 12.2v.

Under a load of about 8amps I noticed it dropped to about 11.6v. After the load was removed it came back to 12.2v again.

Just looking at the charts for 12v AGM 12.2v is roughly 50% SOC.

Obviously the Trimetric is only as accurate as the setpoints, which I set when I got it about 3 years ago and obviously the batteries will lose capacity over time.

So having said all that, and that I can't check them with a hydrometer as they are sealed, in your opinions are they getting close to the end of their life?

If so do you reccommend using similar batteries again, considering my fairly light usage and that I can get these Vision batteries of 100Ah and 200Ah fairly cheaply 2nd hand?

Attachment not found.
Off Grid shack - Victoria Australia. 480W array, 500Ah AGM at 12V. 30A PWM Manison CC. Trimetric 2030. 300W Pure Sine Inverter. 120lt Dometic Gas Fridge. Composting Toilet. 5000lt water tank with 12v 35psi pump. Bosch Hydropower 16 for nice hot water. 4kw Fuji Micro Generator (dead after 7 years) 5kva Subaru Generator.
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Comments

  • jcheil
    jcheil Solar Expert Posts: 722 ✭✭✭
    #2
    Re: New Battery Time?

    Those batteries are really designed to be used in a UPS or "stand-by" operation. They are not really designed to be cycled each day.
    The fact that you got 7 years out of them is amazing - and great! But yes, it appears the time has come. They don't owe you anything.

    But before you buy any more, be sure to go over your loads and (and future loads) so you can be sure you are getting the right battery (and capacity) for the job in the future.
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #3
    Re: New Battery Time?

    If the price is right, and you were happy with them, then sure get another set. Sealed Lead Acid, do you know if they are Gel or AGM style ? AGM is more robust, gel needs to limit the recharge amps to not cook them internally.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

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  • basewindow
    basewindow Solar Expert Posts: 63 ✭✭
    #4
    Re: New Battery Time?

    Thanks for your input and I'm lead to believe they are AGM.

    Maybe I've been lucky with these type of batteries and that the only real loads are in the vicinity of 6-10amps when im actually there. (Water Pump and TV)
    Otherwise they are pretty much just in float 20-25 days in the month.
    I'll see what's on offer for replacements.
    Off Grid shack - Victoria Australia. 480W array, 500Ah AGM at 12V. 30A PWM Manison CC. Trimetric 2030. 300W Pure Sine Inverter. 120lt Dometic Gas Fridge. Composting Toilet. 5000lt water tank with 12v 35psi pump. Bosch Hydropower 16 for nice hot water. 4kw Fuji Micro Generator (dead after 7 years) 5kva Subaru Generator.
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