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Battery - Charging with a 0-30V 0-10 A laboratory power supply

Danielrusniak 18285 14
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Treść została przetłumaczona polish » english Zobacz oryginalną wersję tematu
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  • #1 16716340
    Danielrusniak
    Level 2  
    Hello everyone, I can't find it anywhere, can I charge the 77ah 650 A battery with a 0-30V 0-10A laboratory power supply?
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  • Helpful post
    #2 16716371
    Freddy
    Level 43  
    Theoretically, you can, but you need to keep an eye on the voltage and charging current limits.
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  • #3 16716381
    enhanced
    Level 43  
    I mean, it only has to set the voltage because the current will adjust itself if it's right?
  • #4 16716385
    Danielrusniak
    Level 2  
    Well, I do not know ... it should work like a rectifier ... And the battery gives resistance?
  • #5 16716391
    enhanced
    Level 43  
    Well, you will definitely set the voltage and drive, the intensity will adjust itself over time, i.e. it will decrease.

    This battery has discharged, do you want to connect for tests?
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  • #6 16716395
    Jawi_P
    Level 36  
    Just keep an eye on the tension.
    At most, you can limit the current more than the battery itself, if you wanted to charge it slower.
  • #7 16716397
    Danielrusniak
    Level 2  
    Discharge and test :)
  • #8 16716399
    Freddy
    Level 43  
    Danielrusniak wrote:
    Discharge and test :)
    If you want to discharge yourself, I invite you to the gym.
    Write clearly and in Polish what you expect and what you want to do.
  • #9 16716408
    Danielrusniak
    Level 2  
    Sorry, he writes from the phone .... it has discharged, I have already bought a new one, but I want to test it on the old one, it will definitely be useful one day.
  • #10 16716417
    Freddy
    Level 43  
    Then buy it, or make yourself a car charger.
  • #11 16716554
    Sniezynka
    Level 33  
    Hello,
    I charge this way for a 70Ah battery, I set the short-circuit current of the power supply to 7A and the no-load voltage to 14.6V.
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  • #12 16716758
    tadkli9743
    Level 25  
    Hello

    I have a battery to charge: a car battery 12V / 61Ah, a tractor (lawn mower) 12V / 20Ah, and a motorcycle 12V / 14Ah I charge all with a 12V-6A charger.
    I charge the car and tractor batteries directly with a charger, while the motorcycle batteries are charged with a light bulb limiting the current to 1.5A.
    I connect the rectifier to the autotransformer in order to limit the voltage at the battery terminals to a maximum of 14.6V.
    During the charging process, I have a voltmeter connected to the battery terminals and an ammeter in series with the battery.

    When using a laboratory power supply, make sure that the voltage does not exceed 15V on the battery.

    Regards
  • #13 17632631
    Anonymous
    Level 1  
  • #14 17632707
    gimak
    Level 41  
    marianek70 wrote:
    These are my observations and I do not want to prove anything to anyone or perhaps impose my ignorance.

    And these are correct observations, just check it out for full knowledge
    marianek70 wrote:
    As I gave 15.9 for a moment, he started taking 3.15 A.

    what voltage, with the same settings, will be given by this power supply loaded with only a capacitor, because this is the actual value of the voltage to which it would aim if it were not for the electrolysis of water.
    marianek70 wrote:
    After about 3 hours, the ammeter on the power supply stopped at 0.40 A. The battery started to hum slightly

    This humming is probably due to the electrolysis of the water. I have not encountered this humming noise in my batteries.
    If it is a switched-mode power supply, it will not increase, but if it is transformer, it will increase.
    And by the way, this starting current of 3.15 A, with a switching power supply, would drop quickly and in the end it would be a maximum value of 300-400 mA.
  • #15 17632953
    Anonymous
    Level 1  
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Topic summary

✨ Charging a 77Ah 650A battery with a 0-30V 0-10A laboratory power supply is theoretically possible, but requires careful monitoring of voltage and current. Users suggest setting the voltage to around 14.4V and limiting the current to prevent overcharging. The charging process involves adjusting the voltage while the current decreases as the battery charges. Some users have successfully charged similar batteries using laboratory power supplies, emphasizing the importance of not exceeding 15V at the battery terminals. Observations indicate that the current will drop significantly as the battery reaches full charge, and caution is advised to avoid electrolysis and overheating.

FAQ

TL;DR: Yes—you can charge a 12 V lead‑acid (e.g., 70–77 Ah) with a lab PSU using ≈0.1 C (7 A for 70 Ah); “Keeping what is recommended 1/10 I set the current to 7 A.” [Elektroda, Anonymous, post #17632631]

Why it matters: This FAQ shows safe, repeatable CC/CV settings so your bench supply won’t overcharge or cook a car battery.

Quick-Facts

Quick Facts

Can I charge a 12 V 77 Ah car battery with a 0–30 V, 0–10 A lab power supply?

Yes. Configure the lab PSU for battery charging: set a safe voltage and enforce a current limit. Monitor both. A 10 A ceiling is adequate for a 77 Ah unit if you limit current and watch temperature and gassing. “You need to keep an eye on the voltage and charging current limits.” [Elektroda, Freddy, post #16716371]

What voltage should I set on the PSU for a 12 V lead‑acid battery?

Use about 14.4–14.6 V at the battery terminals during charging. Keep the battery under ~15 V to avoid overcharge stress. A simple voltmeter across the battery helps verify the setpoint. One forum member used an autotransformer upstream of a rectifier to keep the battery below 14.6 V. [Elektroda, tadkli9743, post #16716758]

How much charging current is appropriate for a 70–77 Ah battery?

A practical target is ≈0.1 C. Example: limit to 7 A for a 70 Ah battery. In testing, current naturally tapered from several amps to about 0.40 A as the battery approached full. “Keeping what is recommended 1/10 I set the current to 7 A.” [Elektroda, Anonymous, post #17632631]

Do I just set voltage and let current “sort itself out”?

Set both. Start with a current limit to protect the supply and battery, then hold voltage around 14.4–14.6 V. As state of charge rises, the current will decrease on its own. That’s expected CC→CV behavior on a lab PSU used as a charger. [Elektroda, enhanced, post #16716391]

Quick how‑to: How do I charge with a lab PSU safely?

  1. Set current limit (e.g., ≈0.1 C) and adjust output to ~14.6 V.
  2. Connect PSU to battery with correct polarity; start charging and monitor.
  3. Stop when current falls low and gassing begins; do not exceed voltage limit. These settings worked for a 70 Ah example. [Elektroda, Sniezynka, post #16716554]

Is a lab power supply better than a car battery charger?

It depends. Many say it’s not necessary; others prefer the control and visibility. A user noted a 10 A lab PSU let them watch the V–I relationship closely and limit current to the recommended ≈0.1 C. The trade‑off is higher cost and more hands‑on monitoring. [Elektroda, Anonymous, post #17632631]

How long might charging take with these settings?

One test on a 72 Ah battery at 14.4 V showed current falling to about 0.40 A after ~3 hours, indicating near‑full charge. Exact time varies with battery condition and starting SOC. Use current taper and gassing onset as practical endpoints. [Elektroda, Anonymous, post #17632631]

Is it safe to push the voltage above 15 V briefly?

Raising voltage to ~15.9 V increased current to ~3.15 A and caused audible humming, a sign of water electrolysis. That’s an edge case and not recommended for sustained charging. Keep the battery under about 15 V during normal charging to limit gassing. [Elektroda, gimak, post #17632707]

Can I charge small batteries (e.g., 12 V 14–20 Ah) with the same PSU?

Yes, if you reduce current. One user limited motorcycle battery charge to about 1.5 A using a series bulb and kept voltage ≤14.6 V. Always size the current to the smaller battery’s capacity and monitor voltage at its terminals. [Elektroda, tadkli9743, post #16716758]

Do I need external current‑limiting parts like bulbs or an autotransformer?

A lab PSU has built‑in current limiting. However, some users add a bulb to cap current for small batteries, or use an autotransformer ahead of a rectifier to hold battery voltage ≤14.6 V. These are optional safety aids, not requirements. [Elektroda, tadkli9743, post #16716758]

What signs indicate the battery is nearly full on a lab PSU?

At a fixed 14.4 V setpoint, observed current fell progressively to about 0.40 A. Light gassing or a faint hum may appear near the end. Stop there to avoid unnecessary overcharge. This tapering behavior signals completion on many lab supplies. [Elektroda, Anonymous, post #17632631]

Does the type of lab PSU (linear/transformer vs switching) matter?

Yes. A transformer‑based unit may exhibit different behavior under load and may increase audible hum. A switching supply’s initial current spike typically falls quickly, settling to a few hundred milliamps near finish. Choose a stable unit with reliable CC/CV control. [Elektroda, gimak, post #17632707]

What if my old battery is discharged and I just want to test it?

You can test with a lab PSU by limiting current and holding the voltage around 14.4–14.6 V while monitoring taper. Users discussed reviving and testing an old, discharged unit after replacing it. Keep observations on current decline to judge health. [Elektroda, Danielrusniak, post #16716408]

What is CC/CV in plain terms for this setup?

CC (constant current) limits the maximum amperes the PSU delivers. CV (constant voltage) fixes the battery voltage target. Start in CC to protect the battery, then the PSU transitions to CV as current naturally drops. “At most, you can limit the current more.” [Elektroda, Jawi_P, post #16716395]
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