Have extra Gels and D8s. Need another battery string. Which to use?

softdown
softdown Solar Expert Posts: 3,895 ✭✭✭✭
in Off Grid Solar & Battery Systems #1
Have two extra 109 Ah Alpha Cell gels at 75 lbs/each. Alpha owns Outback. Excellent batteries though may not be ideal for solar. New ones will cost about $250/each with shipping. Expect about 3-4 years of use...that is a wild guess.
Have two extra D8s by Johnson Controls at 125 lbs/each. These are lead acid. Big batteries for big trucks though not ideal for solar. New ones will cost about $200/each with tax. Expect about 2-3 years of use...that is a wild guess.

Seems like a real toss up to me.
First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
· Share on Twitter

Comments

  • softdown
    softdown Solar Expert Posts: 3,895 ✭✭✭✭
    #2
    Have not been able to get a quote on Alpha Gels. I think they will be much higher than I expected. 8Ds can be either starting batteries at 1400 CCA or Deep Cycle. Deep Cycle cost about $250/battery...or almost $50 more than the starting 8D.

    So 8Ds can be alright if you get the Deep Cycle model I would think. No idea about expected longevity.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
    · Share on Twitter
  • softdown
    softdown Solar Expert Posts: 3,895 ✭✭✭✭
    #3
    Looks like two 8Ds were butchered by a combination of running down to 10.5 volts for a couple days then overcharging. I did a two week desulfation procedure. Their resting charge is now 10.7 volts and 11.7 volts. Like I said....butchered.

    So that took me from eight 8Ds down to six. Think I will get two more and cross my fingers. 8Ds are sub par solar batteries but better than hella expensive gels I would think.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
    · Share on Twitter

Categories