Thinking about buying a spare battery for a kids electric bike? For many families, a second battery is one of the most useful upgrades available, especially if your child rides regularly, uses higher speed modes or shares the bike with brothers and sisters.
A spare battery can help reduce waiting time between rides, extend riding sessions and make track days, holidays and weekend riding much easier.
In this guide, we explain typical run times for popular kids electric bikes including Revvi, Amped, RFN Warrior, STACYC and EBOX models, plus when a spare battery is worth buying and when it may not be needed.
Quick Answer
Yes, a spare battery is worth it if your child rides often, uses faster speed modes, rides at tracks or shares the bike with another child.
For occasional garden riding, a spare battery is not always essential. But for regular riders, it can make a big difference by effectively doubling usable ride time.
Find The Right Spare Battery
Looking for a battery for a specific bike? Browse our dedicated battery collections below.
Typical Kids Electric Bike Run Times
Run time varies depending on rider weight, terrain, temperature, speed setting, tyre pressure and riding style. A lighter child riding on flat ground in low mode will usually get much longer run time than a heavier or more confident rider using full power on grass, mud or tracks.
| Bike Model | Typical Run Time | Battery / Notes |
|---|---|---|
| Revvi 12 | Approx. 1–2 hours | 24V 2.6Ah battery, depending on speed mode used |
| Revvi 16 | Approx. 50–85 minutes | Lower speed modes last longer, fastest setting reduces run time |
| Revvi 16 Plus | Approx. 50–85 minutes | Similar run time range to Revvi 16 depending on use |
| Revvi 18 | Approx. 25–80 minutes | Slow approx. 80 mins, medium approx. 45 mins, fast approx. 25 mins |
| Revvi 20 | Approx. 35–90 minutes | 36V 7.5Ah battery, around 90 mins slow / 60 mins medium / 35 mins fast |
| Amped A10 | Approx. 35–60+ minutes | Small starter electric balance bike |
| Amped A16 | Up to approx. 60 minutes | 180W / 24V model, Eco and Boost speed settings |
| Amped A16 Pro | Approx. 60–90 minutes | 400W / 36V higher-performance model |
| Amped A20 | Approx. 45–60 minutes | Good all-round larger youth electric bike |
| Amped A20 Pro | Approx. 45–60 minutes | Higher-performance A20 model |
| Amped A18 Comp | Approx. 60–90 minutes | Premium competition-style model |
| Amped A20 Comp | Approx. 60–90 minutes | Premium 20 inch competition-style model |
| Amped A24 Comp | Approx. 60–90 minutes | Larger premium model for taller riders |
| RFN Warrior SX-E400 | Approx. 60–75 minutes | Mini electric motocross-style bike |
| RFN Warrior SX-E500 | Approx. 60–75 minutes | More powerful RFN Warrior model |
| RFN Warrior SX-E700 | Approx. 60–75 minutes | Higher-performance RFN Warrior model |
| STACYC 12eDRIVE | Approx. 30–60 minutes | Starter premium electric balance bike |
| STACYC 16eDRIVE Brushless | Approx. 30–60 minutes | Premium 16 inch brushless model |
| STACYC 16eDRIVE ELITE | Approx. 30–45 minutes | High-performance premium STACYC model |
| STACYC 20eDRIVE | Approx. 30–60 minutes | Larger premium STACYC model |
| EBOX Models | Varies by model and riding style | Higher-performance models use more power, especially on trails and tracks |
Who Should Buy A Spare Battery?
A spare battery is most useful for families who want longer riding sessions without waiting for the original battery to recharge.
A spare battery is worth considering if:
- Your child rides most weekends
- The bike is used at tracks or practice areas
- Multiple children share one bike
- Your child often rides in the faster speed modes
- You take the bike on holidays, camping trips or days out
- You want to avoid waiting several hours for the battery to recharge
- You own a higher-performance model such as a Revvi 18, Revvi 20, RFN Warrior, Amped Comp or EBOX bike
Who Probably Does Not Need A Spare Battery?
Not every rider needs a second battery straight away. For very young or occasional riders, the standard battery may be more than enough.
- Garden-only riders doing short sessions
- Very young children still learning balance and throttle control
- Families using the bike once or twice per week
- Riders who mainly use the lowest speed setting
If your child normally finishes riding before the battery runs flat, a spare battery may not be essential immediately.
Which Bikes Benefit Most From A Spare Battery?
Revvi 12
The Revvi 12 can already offer a good amount of run time for younger riders, especially in lower speed modes. However, a spare or upgraded battery can be useful if the bike is shared between children or used regularly.
Revvi 16 & Revvi 16 Plus
The Revvi 16 and 16 Plus are popular first electric bikes for young riders. A spare battery is useful for families who want longer weekend riding sessions without stopping for a full recharge.
Revvi 18
The Revvi 18 is one of the models where a spare battery makes the most sense. Confident riders using medium or fast modes can reduce run time significantly, so a second battery can be a very worthwhile upgrade.
Revvi 20
The Revvi 20 is a larger and faster model, often used by older and more confident riders. If the bike is used for tracks, fields or longer sessions, a spare battery is a strong option.
Amped Models
Amped bikes vary by model, but a spare battery is most useful on the A20, A20 Pro and Comp models where riders are likely to use more power and ride for longer periods.
RFN Warrior SX-E Models
The RFN Warrior SX-E400, SX-E500 and SX-E700 are more motocross-style electric bikes. A spare battery can be very useful for longer practice sessions, especially where the rider is using the bike more aggressively.
EBOX Models
EBOX bikes are generally ridden by older and more experienced riders, often covering longer distances and using more power than smaller electric balance bikes.
If you regularly ride trails, practice areas or tracks, a spare battery can significantly extend your riding time and reduce interruptions caused by charging.
For many EBOX owners, a second battery is one of the most useful accessories available.
Spare Battery vs Bigger Battery Upgrade
Some models allow upgraded batteries, while others are best supported by keeping a second standard battery charged and ready.
A larger battery upgrade may increase run time in one session, while a spare battery gives you the flexibility to swap over and continue riding once the first battery is flat.
| Option | Best For | Main Benefit |
|---|---|---|
| Spare Battery | Longer days out, multiple riders, track use | Swap batteries and keep riding |
| Upgraded Battery | Models with compatible higher-capacity batteries | Longer run time from one battery |
| Second Charger | Families with multiple batteries | Charge more than one battery at a time |
Why Run Time Varies So Much
Battery run time is never exact. Two riders on the same bike can get very different results depending on how and where the bike is used.
- Speed mode: Faster settings use more power.
- Rider weight: Heavier riders usually use more battery power.
- Terrain: Grass, mud, hills and soft ground reduce run time.
- Throttle use: Constant hard acceleration drains the battery faster.
- Temperature: Cold weather can reduce lithium battery performance.
- Tyre pressure and maintenance: Poorly maintained bikes can use more energy.
Our Recommendation
For casual riders, start with the standard battery and see how often your child runs it flat.
For regular riders, track riders or families with more than one child using the same bike, a spare battery is usually worth buying.
It is one of the easiest ways to extend riding time without buying a bigger bike or waiting around for a recharge.
Spare Battery Safety Tips
- Only use the correct battery for your exact bike model
- Do not leave lithium batteries fully flat for long periods
- Store batteries indoors in a cool, dry place
- Do not charge batteries unattended overnight
- Allow batteries to cool before charging after hard use
- Check connectors regularly for damage or dirt
- Use the correct charger supplied for the battery
For more advice, read our full kids electric bike battery care guide.
Frequently Asked Questions
Can I buy a spare battery for a kids electric bike?
Yes, many kids electric bikes have removable batteries and compatible spare batteries available. Always make sure the battery matches the exact make and model of bike.
Does a spare battery make the bike faster?
No. A spare battery does not usually increase speed. Its main benefit is increasing total available ride time by allowing you to swap batteries.
Can I charge two batteries at once?
Only if you have two suitable chargers. Do not try to charge two batteries from one charger unless the manufacturer specifically allows it.
Should I buy a spare battery with the bike?
If your child is likely to ride regularly, use the bike at tracks or share it with another child, buying a spare battery with the bike can be a good idea. For occasional use, you can always add one later.
How long do kids electric bike batteries last?
This depends on the model, battery size, riding conditions and how the battery is cared for. Correct charging and storage can help improve battery life over time.
How much does a spare battery cost?
Battery prices vary depending on the bike model, voltage and capacity. Smaller batteries for starter electric balance bikes are generally more affordable, while larger high-performance batteries for older riders cost more. Check individual battery listings for current pricing.
Can I use a different brand battery?
No. You should only use a compatible battery designed for your specific bike. Using the wrong battery can damage the bike and may create safety risks.
Shop Spare Batteries For Kids Electric Bikes
At Garland Powersports, we stock spare batteries and replacement battery options for selected Revvi, Amped, RFN Warrior, STACYC, EBOX and kids electric bike models.
Why Buy From Garland Powersports?
- Specialist UK kids electric bike retailer
- Genuine replacement parts and spares
- Fast UK delivery available
- Support for Revvi, Amped, RFN Warrior, STACYC and EBOX models
- Helpful advice before and after purchase