A useless automotive battery is a irritating state of affairs—particularly should 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 assist 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 personal threat. All the time 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 (should you don’t have AC energy out there or your charger doesn’t assist AC). Automotive batteries are massive (30–70Ah) and want numerous vitality to get well if deeply drained.
- Multimeter (non-compulsory, 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, verify 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 begin 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 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 must cost barely increased than that.
Step 2: Configure Charging Parameters
- Energy on charger.
- Choose Pb (lead-acid) battery kind.
- 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 advocate 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 Automotive Battery
Connect the XT60-to-alligator clip cable. Clip pink to + (optimistic), black to – (destructive) on the automotive battery.
You would possibly see a spark when hooking up the cable, which is regular so long as the polarity is appropriate.
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 step by step 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.
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 automotive began with none downside.
Essential Security Notes
- Don’t quick cost. Lead-acid batteries desire sluggish charging. Persist with 0.1C to be protected.
- Don’t over-discharge your enter battery (if utilizing a LiPo to energy the charger) – frequently monitor each enter and output voltages.
- Put money into a correct automotive battery charger should 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 kind can rescue an empty battery in your automotive or motorbike. It’s not a alternative for a devoted automotive charger, however it’s an ideal emergency hack and would possibly prevent on the spot while you don’t have any skilled instruments— particularly for RC hobbyists who already personal a succesful LiPo charger.
