Find Answers to Questions

Here are some answers to frequently asked questions. Don't see your question? Write us at

Do I need to fully cycle my battery every month?

This is a question we often get and is a common misconception.

Modern lithium-ion batteries do not need to be cycled.

This misconception comes from a “memory effect” in old, nickel batteries. In these batteries, the memory effect caused the batteries to “remember” different minimum and maximum charges. If you took down the battery from 100% to 20% over and over again, the battery would remember 20% as the minimum charge. In future cycles, the battery would not go below 20%.

Lithium-ion batteries are not affected by the memory effect. This is another reason they are so popular. You can take your battery down to 50% over and over again without damaging the battery. In fact, the number one cause of battery deterioration is repeated cycling. So it's better for your battery to avoid draining it and recharging it.


What causes wear on lithium-ion batteries?

Your phone, computer, and CoBattery all use lithium-ion batteries. Lithium-ion batteries, unsurprisingly, use lithium ions to store charge. In a fully charged battery, the positively charged lithium ions rest on the positive electrode.

When a load, such as a phone or light, connects to the two two electrodes the battery begins to discharge. During discharge the lithium ions move from positive to negative electrode and the electrons move in the opposite direction on the circuit, powering the load. In a fully depleted battery, the lithium ions aggregate at the negative electrode.

Lithium-ion batteries became popular due to their reusability. After discharge, a battery charger uses a voltage potential to move lithium ions back to the positive electrode. So in theory you can use a lithium battery infinite times by shuttling lithium ions back and forth between electrodes.

In practice, lithium ion batteries degrade with each discharge and charge.

During each charge cycle, some ions chemically react with each electrode to form a lithium metal. Once the ions have formed a metal, they can no longer move from electrode to electrode. The capacity of the battery depends on how many ions it can move around. So the capacity of the battery decreases with every ion that forms into a metal.

Furthermore, each charge cycle damages the electrodes themselves. The electrodes' crystal structure allows them to hold ions in slots in the crystal. So a bigger electrode has more slots and thus can store more charge. When ions move into the electrode, the ions stretch the crystalline electrode. In time, this repeated stress causes microscopic damage to the electrode that reduces the number of ions that it can hold.

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How does the charging dock work?

The charging dock has one light that is either red or green. When you insert a battery in the charging dock, ensure the gold pads on the bottom of the battery align with the pins in the charging dock.

If the light is green, the battery is fully charged OR the charging dock does not detect a battery. So if you have the charging dock without a battery, the light should be green.

If the light is red, the battery is currently charging. It takes 4-6 hours to fully charge a depleted battery. So the charging dock light should remain red for this time while the battery is charging.

Sometimes with the current charging dock you may need to wiggle the battery to ensure a continuous red charging light. We are working on a new charger that will not have this problem.

If any of that doesn’t work or doesn’t make sense, contact us at .

How do I know if my phone is using CoBattery?

For CoBattery to work, you need to have the lightning connector plugged into your phone’s port.

If your battery has charged and your CoBattery is working properly, your top bar should look like this:

The lightning bolt to the right of the battery indicator shows that the phone is using power from the CoBattery case.

If your phone is not at 100%, it will use the CoBattery battery to charge up to 100% and then it will run off the battery in the case.

Can you use CoBattery with headphones?

Unlike other battery cases, CoBattery does not block the audio jack on your phone. So you will be able to plug in whatever headphones you have, no dongles necessary.

Will CoBattery protect my phone?

The sides of CoBattery come slightly in front of your phone’s screen. So when your drop CoBattery face down, the case hits the ground, not your phone.

Every week a new customer writes in telling us how CoBattery protected their phone from a hard fall.

If you drop CoBattery on it’s side, the shock absorbent plastic will take the brunt of the fall. And the battery will eject on extra hard falls in order to take some of the kinetic energy from the fall.

A drop test. The battery ejects to absorb kinetic energy from the fall.

How long does it take to charge a battery?

CoBattery comes with a charging dock to charge up your batteries. In the charging dock, a battery should take 4 to 6 hours to go from 0 to 100%.

The CoBattery battery should last for about one day of normal usage. So by the time that the battery on your case is dead, you should have a fully charged battery in the charging dock, ready to swap.

Will the battery fall out of my case?

This is something we made sure to get right. You don’t want to be in the last mile of a marathon, still at 100%, and the battery on your case fall out in the final sprint to the finish line.

The battery fits snug into the case with ridges on the top and bottom of the battery that secure it into place. Pins on the bottom of the case exert upward pressure, ensuring the battery stays in position.

To protect your phone, the battery is designed to fall out on hard falls. This battery ejection takes some of the kinetic energy out of the fall so that your phone experiences less of a shock.

How long does each battery last?

Each battery holds 3,000 mAh.

3,000 mAh is roughly 1.5 times the internal iPhone 7 battery. That should be more than enough charge to last you the day.

Is CoBattery MFi Certified?

CoBattery is not MFi certified.

We designed our own lightning connector that allows for a slimfit case that does not jut out beneath your phone. MFi certification requires that you use an Apple-specified connector that is pretty bulky. That is why all other battery cases have a bulky chin at the bottom. 

CoBattery comes with a case, two batteries, and a charging dock for $79.