A useless automotive battery is a irritating scenario—particularly in the event you don’t personal a devoted automotive charger. I lately discovered myself caught with a drained automotive battery that wouldn’t crank the engine. With out entry to a devoted automotive battery charger, I made a decision to make use of my RC LiPo charger, since many trendy fashions help Pb (lead-acid) batteries as properly. It labored surprisingly properly, 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 individual 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 automotive battery terminals, purchase it right here
- A big battery to energy your charger (in the event you don’t have AC energy obtainable or your charger doesn’t help AC). Automobile batteries are massive (30–70Ah) and wish a number of vitality to get well if deeply drained.
- Multimeter (non-compulsory, 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 automotive battery’s voltage along with your multimeter to get an concept. If the battery exhibits 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 automotive.
A fast google reveals {that a} typical automotive 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. Understand that the voltage will drop barely after you cease charging, so you’ll most likely have to cost barely larger than that.
Step 2: Configure Charging Parameters
- Energy on charger.
- Choose Pb (lead-acid) battery sort.
- Cell Rely: For a 12V automotive 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 automotive battery is a 50Ah, 0.1C that will be 5A.
Step 2: Join Charger to Automobile Battery
Connect the XT60-to-alligator clip cable. Clip purple to + (constructive), black to – (adverse) on the automotive battery.
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 steadily 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 automotive began with none downside.
Necessary Security Notes
- Don’t quick cost. Lead-acid batteries desire sluggish charging. Keep on with 0.1C to be secure.
- Don’t over-discharge your enter battery (if utilizing a LiPo to energy the charger) – often monitor each enter and output voltages.
- Spend money on a correct automotive battery charger in the event you’ll be doing this usually and extra safely. Get one right here:
Conclusion
In case you’re in a pinch, an RC LiPo charger that helps Pd battery sort can rescue an empty battery in your automotive or bike. It’s not a substitute for a devoted automotive charger, nevertheless it’s an awesome emergency hack — particularly for RC hobbyists who already personal a succesful LiPo charger.
