A useless automobile battery is a irritating scenario—particularly should you don’t personal a devoted automotive charger. I lately discovered myself caught with a drained automobile battery that wouldn’t crank the engine. With out entry to a devoted automobile battery charger, I made a decision to make use of my RC LiPo charger, since many fashionable fashions help Pb (lead-acid) batteries as nicely. It labored surprisingly nicely, and I’ll present you precisely how I did it on this tutorial.
⚠️ Disclaimer: Charging lead-acid batteries with an RC LiPo charger is a workaround, not a long-term answer. Use it at your individual danger. At all times observe security precautions round batteries.
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What You’ll Want
- A LiPo charger that helps Pb (lead-acid) batteries, for instance:
- XT60 (feminine) to alligator clips cable – for connecting to the automobile battery terminals, purchase it right here
- A big battery to energy your charger (should you don’t have AC energy accessible or your charger doesn’t help AC). Automotive batteries are huge (30–70Ah) and wish a number of power to get better if deeply drained.
- Multimeter (elective, to double-check battery voltage — your charger can show voltage anyway). Learn to use a multimeter on this tutorial: https://oscarliang.com/multimeter-fpv/
Step 1: Measure the Battery Voltage
Earlier than charging, test the automobile battery’s voltage along with your multimeter to get an concept. If the battery reveals a wholesome voltage however nonetheless can’t crank the engine, the difficulty possibly one thing else.
In my case, the battery was just below 11V, and it wasn’t sufficient to start out the automobile.
A fast google reveals {that a} typical automobile battery ought to learn round 12.6–12.8V when the engine is off, and as much as 14.4V when the engine is operating. That’s why I’ll attempt to cost my battery to 12.6V. Needless to say the voltage will drop barely after you cease charging, so you’ll in all probability must cost barely greater than that.
Step 2: Configure Charging Parameters
- Energy on charger.
- Choose Pb (lead-acid) battery sort.
- Cell Depend: For a 12V automobile battery, select 6S Pb (2V per cell × 6 = 12V).
- Cost Present: Use 0.1C (I searched and most of the people advocate 0.1C in order that’s what I’m gonna use). My automobile battery is a 50Ah, 0.1C that will be 5A.
Step 2: Join Charger to Automotive Battery
Connect the XT60-to-alligator clip cable. Clip purple to + (optimistic), black to – (detrimental) on the automobile battery.
Step 4: Charging the Battery
- Begin charging and keep watch over the present and voltage in your charger’s show.
- Relying on how your charger works, the method ought to look one thing like this:
- The present ramps up steadily over the primary minute.
- It then delivers a gentle present till the battery approaches its full voltage (~14.4V).
- The present then tapers off right into a trickle cost because the battery tops off.
Nevertheless, in my case, I let it cost for about half-hour and manually stopped at round 13V. After resting, the voltage dropped to barely over 12V (which is regular), and the automobile began with none drawback.
Necessary Security Notes
- Don’t quick cost. Lead-acid batteries desire gradual charging. Keep on with 0.1C to be protected.
- Don’t over-discharge your enter battery (if utilizing a LiPo to energy the charger) – recurrently monitor each enter and output voltages.
- Spend money on a correct automobile battery charger should you’ll be doing this typically and extra safely. Get one right here:
Conclusion
If you happen to’re in a pinch, an RC LiPo charger that helps Pd battery sort can rescue an empty battery in your automobile or motorbike. It’s not a substitute for a devoted automotive charger, however it’s an important emergency hack — particularly for RC hobbyists who already personal a succesful LiPo charger.
