Automotive style battery tester

softdownsoftdown Solar Expert Posts: 3,137 ✭✭✭✭
With a small fleet of aging cars, trucks and 4WDs, healthy batteries can be a challenge. Decided to give an automotive style battery tester a chance. This one is designed for pretty large batteries - up to 220 Ah or 2000 CCA. My FullRivers are 270 Ah - there is that. Finding a battery tester for that size battery was not immediately fruitful. Worthwhile investment just for auto batteries I think. Many believe car batteries are not lasting anything like they used to. A curious development considering the damage that modern car computers can receive from battery problems. 

Our host does not appear to offer a "solar battery tester" at this time.
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


  • mike95490mike95490 Solar Expert Posts: 8,757 ✭✭✭✭✭
    Solar batteries are not designed to be tested in a 30 sec test.   You need to deplete the battery to a known voltage at an known temperature, let things stabilize for a few hours, then carefully recharge and see how much power is needed to refill the battery.  But this can take 2 days to complete, and nobody does it.  If you kept daily logs of Discharge and Recharge, you can see any developing trend as the battery ages. ( as it ages, the recharge efficiency goes down)  Of course the gold standard is to measure the specific gravity, but can't do that with AGM
    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: ,

  • Marc KurthMarc Kurth Solar Expert Posts: 757 ✭✭✭✭
    mike95490 said:
    Solar batteries are not designed to be tested in a 30 sec test.   You need to deplete the battery to a known voltage at an known temperature.................

    This is the ONLY test that is accepted by Concorde and Fullriver, so this is the only way that we test battery capacity. (Based on known parameters as you said) I can list many, many examples of people condemning batteries based on their high end capacitance tester. 
    Example: If a battery is rated to provide 400 ah, and it gives me 400 ah - I have no doubt of what the storage capacity of that battery is. It really does boil down to this very simple and reliable approach

    I always have more questions than answers. That's the nature of life.
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