A useless automobile battery is a irritating state of affairs—particularly if you happen to 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 help 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 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 (if you happen to don’t have AC energy obtainable or your charger doesn’t help AC). Automotive batteries are large (30–70Ah) and wish a whole lot of power to get well if deeply drained.
- Multimeter (elective, 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, test 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 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. Remember that the voltage will drop barely after you cease charging, so you’ll most likely have to 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 suggest 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 + (constructive), black to – (unfavorable) on the automobile battery.
You may see a spark when hooking up the cable, which is regular so long as the polarity is right.
Step 4: Charging the Battery
- Begin charging and regulate 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 progressively 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.
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.
Essential Security Notes
- Don’t quick cost. Lead-acid batteries choose 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) – repeatedly monitor each enter and output voltages.
- Spend money on a correct automobile battery charger if you happen to’ll be doing this typically and extra safely. Get one right here:
Conclusion
In the event you’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 substitute for a devoted automotive charger, however it’s a fantastic emergency hack and may prevent on the spot if you don’t have any skilled instruments— particularly for RC hobbyists who already personal a succesful LiPo charger.