A lifeless automobile battery is a irritating scenario—particularly for those who don’t personal a devoted automotive charger. I not too long ago 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 trendy fashions assist Pb (lead-acid) batteries as effectively. It labored surprisingly effectively, 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 resolution. Use it at your personal threat. 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 (for those who don’t have AC energy obtainable or your charger doesn’t assist AC). Automotive batteries are large (30–70Ah) and wish a whole lot of power to get better if deeply drained.
- Multimeter (optionally available, to double-check battery voltage — your charger can show voltage anyway). Discover ways to use a multimeter on this tutorial: https://oscarliang.com/multimeter-fpv/
Step 1: Measure the Battery Voltage
Earlier than charging, examine the automobile battery’s voltage together with your multimeter to get an thought. If the battery reveals a wholesome voltage however nonetheless can’t crank the engine, the problem possibly one thing else.
In my case, the battery was slightly below 11V, and it wasn’t sufficient to begin 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 working. That’s why I’ll attempt to cost my battery to 12.6V. Take into account that the voltage will drop barely after you cease charging, so you’ll in all probability must cost barely increased than that.
Step 2: Configure Charging Parameters
- Energy on charger.
- Choose Pb (lead-acid) battery kind.
- 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 may be 5A.
Step 2: Join Charger to Automotive Battery
Connect the XT60-to-alligator clip cable. Clip purple to + (constructive), black to – (unfavorable) 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 regularly over the primary minute.
- It then delivers a gradual 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.
Nonetheless, 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 downside.
Necessary Security Notes
- Don’t quick cost. Lead-acid batteries desire gradual charging. Follow 0.1C to be secure.
- Don’t over-discharge your enter battery (if utilizing a LiPo to energy the charger) – usually monitor each enter and output voltages.
- Spend money on a correct automobile battery charger for those who’ll be doing this typically and extra safely. Get one right here:
Conclusion
For those who’re in a pinch, an RC LiPo charger that helps Pd battery kind can rescue an empty battery in your automobile or bike. It’s not a alternative for a devoted automotive charger, but it surely’s an ideal emergency hack — particularly for RC hobbyists who already personal a succesful LiPo charger.