Interstate Batteries

Anyone have any experience with the Interstate Batteries UL-16HCL? I have 16 of them in series/parallel in a 24-volt system. I recently discovered TWO dead cells. Was wondering IF I can replace just two batteries in the bank. The old ones are almost 5 years old. Will the new ones and old ones "play nice" together? Or do I just have to pony-up the money to replace all 16 to avoid future problems? Unfortunately, some of these batteries got low on water over an extended absence. I presume this is the cause of the premature death of the cells. IF I go with the exact replacement batteries, wiring will be much easier, BUT just do NOT know IF the Interstate brand is comprable to the Trojan brand.


  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: Interstate Batteries

    I'd pull the dead batteries out, and run on the rest till you buy new ones.

    At 5 years, if 2 have gone, the others are not far behind. I'd not mix new with old.
    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

    gen: ,

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Interstate Batteries

    Welcome to the forum ... and to the club.

    I bought Interstates three years ago. Within the first year one cell in one of them shorted out. First time I ever saw that happen in such a short time. They also did not perform to specifications.

    Fortunately the children have run the water pump "after hours" every day for ten days this Summer so I now have to buy knew batteries. Can't expect any brand to stand up to being drain dead day after day. :grr
  • BB.
    BB. Super Moderators, Administrators Posts: 33,471 admin
    Re: Interstate Batteries

    I cannot speak directly to your brand of batteries... But 5-7 years is a "good life" for an inexpensive set of batteries.

    And you are probably correct--exposing plates to air can kill cells pretty quickly.

    More or less, one way to look at adding new batteries is they may shoulder much of the load and cycle more deeply than the rest of the old bank--and "wear down" more quickly to where they will not last much longer than the rest of your bank.

    Another way to look at the problem is you will probably having the rest of the old batteries failing over the next couple of years--so you will be back in there debugging and replacing a battery or two at a time.

    If you are short of cash and/or this is not a "critical" application (power is nice but not needed 100% of the time)--Adding new batteries will, more or less, function OK (with more maintenance and possible shorter life of new cells).

    Or, you can review your power needs and current system and see if now is the time to replace/upgrade the new bank to better meet your needs and reduce the number of parallel strings.

    I am not a big fan of parallel strings of batteries. More cells to check water on, problems with sharing of current (bad cables, bad cells) and one shorted cell can take down the entire bank (I suggest getting a ~$60 DC Current Clamp Meter so you can monitor the charge/discharge current and look for bad connections/cells before they take the string/bank down).

    Two or three parallel strings sort of work OK... And there are people with >3 strings that are happy with their banks--But I would suggest getting higher AH batteries (or cells) and making 1 series string if practical for you.

    If you parallel strings, balancing the current paths for all strings is also helpful:

    Note, for those serious about protecting against electrical fires--Each series string (>2 strings) should have its own high current circuit breaker or fuse to prevent multiple batteries from feeding into a dead short.

    High current fuses/breakers are expensive and sort of painful to mount (in many cases)--So many (most?) people do not properly fuse parallel battery strings.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Interstate Batteries

    I agree with Mike,

    Cull out the bad ones, wire the remaining for the 24 vdc as best you can, keeping cells balanced, and r UN them until they drop. If this is a mission critical system, then consider full replacement, but get your money out of them. I have a couple of l16s that were the remainders of a culled set. I got them free 8 years ago, an after being in 24/7 service for ten years, they have been on summer only light duty for a further 8.

    Welcome to the forum,

  • System2
    System2 Posts: 6,290 admin
    Re: Interstate Batteries

    I surely am glad I found this site!!! Wow, soooooo much information. My thanks to all who replied to my post.
  • Fullpower
    Fullpower Solar Expert Posts: 69 ✭✭
    Interstate Batteries

    I buy scrap batteries.
    Most of them go to the recycler, but if a battery comes in that is not too old, has clear electrolyte, and somewhere close to 2 volts per cell, I will load test it, and see if it takes charge.
    I also sell a fair number of used, charged, load tested, salvaged batteries, mostly 8D marine starting batteries, and a few L-16's normal terms: 60 days money back...
    I have seen several of the Interstate brand UL-16 come in with one dead cell. 4 volts O.C. one cell Stone dead.
    After cooking them for a week, with two cells gassing heavily, gravity over 1.28 we have one cell stone cold, just won't come up.
    Formerly very high quality, The Interstate branded UL16 and high capacity version are manufactured by USBattery in California, there appear to be some quality control issues still in the pipeline.