Battery blew up?!

porch13
porch13 Registered Users Posts: 68 ✭✭✭
I’m getting ready to replace my FLA back with Discover lithium very soon.  As part of the preparation, last night I pulled the battery back out of the box and and just set them up in the corner.  Came down to the utility room this morning and saw that one of the caps had completely blown off a battery.  The battery didn’t get banged around or anything when moving it any idea what could cause this? The battery is still reading over six volts. 
Northern Arizona...4050 Watt off-grid system - Outback FP1 - Rolls 605 in a 48V bank

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,597 admin
    edited January 2023 #2
    Ignition of hydrogen+oxygen inside cell... Cell electrolyte levels low (exposed plates)?
    • Battery(ies) were being charged (generating hydrogen)?
    • Ignition source nearby (loose cable connection under charge, light source overhead with switch sparking)?
    • Very low humidity (nylon/synthetic fabric nearby--somehow got moved and generated static spark)?
    • Any sparks (welding/smoking/using a cigarette lighter/candle as a light source, etc.)?
    • Internal battery fault (old batteries, corrosion, failed internal bus bar)?
    • Batteries old and battery/bank is seeing >~2% rate of charge during float (causes batteries to overheat, excessive gassing, loss of water, etc.)?
    My first guesses.
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • porch13
    porch13 Registered Users Posts: 68 ✭✭✭
    The bank is six years old and has been consuming a lot of water recently.  It happened some time overnight so they weren’t under any type of charge.   No sparks of any kind nearby.  

    I covered the hole and hope the bank can limp along until NAWS gets my new batteries in. 
    Northern Arizona...4050 Watt off-grid system - Outback FP1 - Rolls 605 in a 48V bank
  • Ralph Day
    Ralph Day Solar Expert Posts: 1,020 ✭✭✭✭
    Spooky!
    I have Surrette S550's as well.  How do the water miser caps perform?  I add about 100-150 ml of water each month or two.  1/2 cup or so
  • porch13
    porch13 Registered Users Posts: 68 ✭✭✭
    I think the caps helped quite a bit.  For years I used a very reasonable amount of water.  Recently the amount has gone through the roof.  It’s my fault.  I had one battery that was not like the others and I ignored it instead of pursuing warranty.   That guy took out the whole string.   😕
    Northern Arizona...4050 Watt off-grid system - Outback FP1 - Rolls 605 in a 48V bank
  • Riley
    Riley Registered Users Posts: 67 ✭✭
    Jeeze, my exact batteries. 
    Good to know. Now I can be even more obsessed with measurements and watering. 
    Mine currently use very little water. 

    Off-grid: XW+6048 / 48V FLA battery bank (428 A/H (Rolls S-550 batteries)) / Conext MPPT 60 150 charge controller / SCP / Insight gateway / 12 - 260W solar panels / Kohler 12KW 12-RES propane genset