Q & A Guides

Can I Charge My Scooter Battery With A Car Charger?

You bet you can!

A dead scooter battery means a lot of things, but high on the list are two pressing issues. One, no one wants to spend money on something as boring as a new battery. And two, it could ruin your weekend joy ride plans.

Car batteries and scooter batteries are both 12 volts. So car chargers can absolutely be used to charge a scooter battery. But there will be a few things you’re going to need to consider before you get charging.

Is The Charging Process Safe

While voltage may be the same, scooter batteries are not as large. This means, they don’t have the same “capacity” as a car battery. The more technical term is Ah, or amp hours. Car batteries can have a wide range of amp hours. A typically small car battery has around 48 amp hours. In contrast, a scooter battery has around 10 amp hours. Even though there’s a big difference in amp hours, you can still charge your scooters battery with a car battery charger. However, understanding what amps and amp hours are helps you be safer and extend your batteries life.

What Are Amp Hours And Why Do They Matter

I’m a layman, so I will proceed as such for the remainder of the article. First, we need to know what are amps and amp hours.

An example that works for me is the soda and a straw analogy. The size of the soda cup represents the physical size (volume) of the battery. The straw, and its diameter, represents the flow rate of an electrical charge (amps) as it moves from the battery to the thing using its power. And the thirst of the person drinking the soda represents the power needed to make the thing run. Asking “How many amps hours does this battery have?” would be like asking “How long will it take someone to drink this soda?”. To calculate the answer you need to know a few things. How much soda is in the cup, what is the diameter of the straw, and how thirsty is the person. A thirstier person (a car) will need a bigger cup (battery) with a larger straw (more amps). This would then of course mean the opposite is true. A scooter (less thirsty) has a smaller battery (smaller cup) and does need as many amps (small straw). Wow. I hope that makes sense.

How does this tie back into charging a scooter battery?

By using a battery charger designed to work with a car, you’re using a tool that was intended to refill a large cup though a big straw as efficiently as possible. Understanding this concept will help you make the necessary adjustments to properly change your scooters smaller battery.

How Long Will The Battery Take To Charge

Now that we better understand the relationship between the charger and the battery, we’ll be able to correctly adjust the battery chargers settings, and estimate the time needed for a full charge. Somewhere on all car chargers you’ll see a voltage and an amperage rating.  While there may be exceptions, most car chargers will have a 12 volt option. The amperage is where things can vary big time. As an example, I just did an Amazon search and found the NOCO Genius Series of chargers ranged from 0.75 amps to 26 amps.

The rule of thumb is 1 amp output will recharge a rate of 1Ah/per. Remember, a scooters battery is around 10 amp hours. So using a 1 amp charger will take about 10 hours for a full charge. A 3 amp charger should do the job in about 3 hours.

A word caution. If you’re anything like me, your brain is telling you “Sounds like bigger is better!”. While technically this may be true, it comes at a cost.

Battery Charging Best Practices

More power may charge the battery faster, but you’re running the risk of overcharging the battery and causing permanent damage. While the risk of overcharging as declined due to manufactures adding features to monitor the battery level, how fast the battery charges is based on amperage rating. Car chargers start at around 18 amps and go up from there. In general, batteries will last longer and preform better if you slow down the charging process. So charging a 10 amp scooter battery with an 18+ amp charger will charge faster, but should only be done if there are no other options and you’re interested in extending the batteries life span.

Naturally it’s best to refer to your user manual to see if its give you instructions on how to best care for your battery, but in general, using a battery charger in the 1 amp range is recommend.

Reduce The Risk Of Overcharging

As mentioned, modern battery chargers come with the built-in ability to detect when the battery in fully charged, so risk of overcharging is unlikely. Matter of fact, some chargers have a trickle charging feature, where after the battery is fully charged it will “trickle” a small of power to make sure the battery is topped off and ready for use when you need it. A step up from there, as suggested by others, is a “float charging mode”. While I still don’t fully understand how this feature works, I was told it does even less damage to a battery than a trickle charge. If anyone knows a bit more about this, I’d love to hear about it in the comments.

Battery Charger Suggestions

As we’ve mentioned, if you have a car battery charger and that’s it… use it. But if you need some recommendation, I’ve put together this short list of battery chargers that are better suited for the job.

Budget-Friendly: BLACK+DECKER BM3B

  • Amps: 1.5
  • Price Range: $14.00 to $19.00
  • Features: Trickle charge. Sealed to protect against, moisture, oil, and dust. Can be mounted.

Mid-range: NOCO Genius G750 UltraSafe Smart Battery Charger

  • Amps: 1.1
  • Price Range: $25.00 to $30.00
  • Features: Trickle charge. Has spark-proof safety design. Can be used with deep-cycle batteries. Ultra compact and lightweight. 

High-end: Battery Tender Plus 021-0128

  • Amps: 1.25
  • Price Range: $45.00 to $50.00
  • Features: Float charging mode is enabled automatically after battery is done charging. Manufacture states it can charge as fast if not faster than its competitions 3-amp models. 

Hope this helps. Ride safe!

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One Comment

  1. Hi.

    I have a 36v 15AmpH e scooter (segway Ninebot max).

    I am planning to carefully build an upgrade external battery to boost range.

    My understanding from research is that if I increase amp hours, I will get more range per charge.

    I heard someone say my scooter controller can only handle a maximum voltage of 52v, though I don’t know how to confirm this.

    And while I am making the new battery pack, I am confused about how many amp hour is the limit?

    I was thinking if I could make a external battery pack (battery booster) with 30amp hours and only 14v extra. I know 14v is safe but I don’t know if too much amp hour can damage the scooter electronics.

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