If the battery just doesn’t give as much range as it used to, it’s typically ok to keep riding. If the battery is swollen, keeps cutting out, or is swollen and breaking out of its case, you have to stop riding.
Super73 S2 Battery Not Holding Charge: Repair Or Sell?
Written by: Robbie Ferri | July 11, 2026 | Time to read 6 min
There's nothing more frustrating than planning a long ride only to discover your battery has other ideas. If your Super73 S2 isn't holding charge like it used to, don't panic just yet.
More about the Author: Robbie Ferri
Robbie is a UK-based ultra cyclist, former bike shop worker, and qualified bike fitter. Deeply passionate about e-Bikes and adventure cycling, he combines hands-on experience with real-world riding to help others go further on two wheels.
E-Bike batteries are like mobile phone batteries. When you get them new, they are incredible. You can go on a three-day hike, and you're still at 90% by the time you get home. A few years down the line, suddenly it’s at 70%, and you just stepped out of the car with clean boots and a bag of trail mix.
The Super73 S2 battery is similar, and it does have a shelf life. The big question you need to ask yourself when it’s going wrong is whether it's time to repair or sell. In this article, we will discuss just that.
👋 Welcome to Upway!
Upway is your top destination for buying and selling e-Bikes online. Discover your next e-Bike at up to 60% off retail prices, available in new or like-new condition.
Common Super73 S2 Battery Not Charging Problems
Before we get into extensive repairs, it’s helpful to quickly troubleshoot any problems you're having. It’s easy to jump to the worst-case scenario when often you don’t need to.
| Problem | Most Likely Cause |
|---|---|
| Range Much Lower Than Normal | Battery ageing and reduced cell capacity. |
| Won't Charge | Faulty charger or Battery Management System (BMS) issue. |
| Cuts Out Uphill | Weak or failing battery cells causing excessive voltage sag under load. |
| Battery Dies at 40% | Cell imbalance or inaccurate battery calibration. |
| Charger Stays Green | Faulty charger, poor connection, or battery communication fault. |
| Battery Gets Hot | Internal battery fault, excessive current draw, or charging problem. |
| Battery Swollen | Dangerous internal battery failure requiring immediate attention. |
How Long Should A Super73 S2 Battery Last?
Batteries on electric bikes generally last between 500 and 1,000 charge cycles. They naturally degrade over time as the cells die, or they just become much less effective. You can make them last much longer by following certain processes such as;
- Keeping the battery above 30%
- Not letting the battery fully deplete
- Keeping the battery at a good temperature
- Not riding in full power all the time
- Using the battery regularly
Most Super73 S2 batteries will last around 3 to 6 years. That’s highly dependent on the amount of use and how it's been treated over its life. Battery losing range over time is normal, and you shouldn’t be concerned unless it's excessive, such as your commuter or e-MTB dropping from 60% to 20% in a few minutes.
Signs Your Super73 Battery Is Failing
There are many signs that a battery might be on its way out and need to be changed. As someone who has seen this more times than I'd like to, here’s what you can expect to start happening.
- Much Less Range
- Battery percentage drops quickly or in chunks
- Battery shutting off under heavy acceleration
- Battery seems to charge really slowly
- Charger switching off when the battery isn’t charged
- Battery just not charging
- Voltage sag is really bad
- Battery getting super hot
- Battery physically swelling (Huge red flag! Never use it again!)
Is My Super73 S2 Worth Repairing With A Bad Battery?
If the battery is completely dead and you are getting nothing from it, it might be worth selling the bike as-is to someone who's interested in buying a new battery. If it’s just a small repair to the battery, then that also makes sense. It really depends on the bike and what’s wrong with it.
Upway Trade-In Is a Great Option
Upway is a website that sells e-Bikes. Before they are sold, they are reconditioned and undergo mechanical and electrical inspections. If your battery isn’t completely dead, then they will take the bike in and get it worked on, ready for the next user.
This would not only put money in your pocket but could also help you put towards a new bike from Upway, without the worry of selling privately or of the battery completely dying while you have the bike. For more information, check out the sell my bike page.
Buying With Upway
If you are in the market for another e-Bike, why not check out Upway? Prices up to 60% off new, fully inspected e-Bikes, and a one-year warranty. It doesn’t get much better!
Can A Super73 S2 Battery Be Repaired?
There’s a big misconception that batteries cannot be repaired. That’s what a lot of bike shops will tell you because they might not have the right contacts to do it. In fact, they can, and you would be surprised at the services some companies can offer.
| Repair | Typical Cost (USD) | Notes |
|---|---|---|
| Charging Port Repair | $50–150 | Typically required if the charging connector or socket has been damaged. |
| Connector or Wiring Repair | $50–100 | One of the most common battery-related repairs, often involving damaged connectors or wiring harnesses. |
| Battery Management System (BMS) Replacement | $100–250 | Usually worthwhile only if the battery cells are still healthy and retain good capacity. |
| Cell Balancing / Battery Service | $75–200 | Can restore performance if the battery cells are out of balance but not significantly degraded. |
| Battery Rebuild (New Lithium Cells) | $300–700 | The original battery casing is reused while all internal lithium-ion cells are replaced. |
As lithium battery technology improves, so does the process of repairing them and extending their lifespan. Here you can see that there are actually some jobs you can do to fix a battery without replacing it. The big factor is that if the cells are dead, there’s really no going back. It's not like you can drop new cells in very easily.
Battery Replacement Costs
A lot of the time, people find it’s the cells and a new battery is required. Unfortunately, the battery is often more costly than a secondhand version of the same bike. Batteries hugely range in cost depending on a few factors. Here’s what to take into consideration.
Battery Capacity
One of the biggest factors is battery capacity. If the battery is a smaller 300Wh-500Wh unit, the cost isn’t generally too bad. If you go from 700Wh to 1000Wh, it’s going to cost a bit more. E-Bike riders sometimes use this time to upgrade the battery capacity to get more range in the future.
Genuine Vs Aftermarket
You don’t just have to shop at Super73 for a new battery. You can buy aftermarket as well. In my opinion, going directly to the bike manufacturers is the best option. Aftermarket batteries are often much cheaper due to poor cell quality or poor manufacturing. It’s like buying either pure, well-known Duracell premium batteries for your TV remote or Energy Plus Mega Super Long Life Amazing Batteries.
Shipping
This might surprise you, but shipping is a big part of battery cost. It’s very difficult to ship batteries because of their weight and the fact that they cannot be knocked around too much. If you're buying from another country or a faraway place, it can significantly raise the cost.
🤝 Enjoy an even greater discount when you trade in your old electric bike today!
Click here for a price estimation
Frequently Asked Questions
Is it safe to keep riding with a failing battery?
Should I repair my battery or buy a new one?
If the whole bike itself is in amazing condition and doesn’t need any other work, then replacing the battery is often the right call. If there’s more work to be done, then you might want to consider your choices.
Does cold weather affect battery performance?
Oh hugely. It reduces the range and heavily affects performance, for example through voltage sag. It doesn’t mean you have a bad battery. Lithium-ion batteries are just not good in cold temperatures.
Key Takeaways
- Don't assume the battery is beyond saving: A lot of the time, batteries can be repaired for much cheaper costs. You would be surprised how many I have come across that have an easy fault, such as a charging port repair.
- Compare repair costs with the bike's overall condition: Before throwing money at a new battery, it’s worth considering the bike's overall condition. If the whole drivetrain needs replacement and the wheels are out of true and require new tires, it might not be the best investment.
- Safety always comes first: If your battery is swelling, overheating, or the bike keeps cutting out, it’s so important to stop riding. This is not a good place for a battery to be, and it will fail and can be dangerous.
