There are various reasons why a battery may not charge:Aging: Over time, batteries naturally age, leading to reduced capacity and diminished charging capability. Aged batteries may struggle to hold a charge or reach the expected charge level.Damage: Physical damage or overcharging during use can lead to battery damage, rendering it unable to charge.Internal Faults: Internal component failures or short circuits within the battery may hinder charging. This could be due to manufacturing defects or other issues.Non-rechargeable Battery: Attempting to charge a non-rechargeable battery can result in failure and potential damage. Ensure the battery is designed for recharging.Charger Issues: Using an incompatible or damaged charger can prevent the battery from charging. Charger malfunctions or connection problems may also affect charging effectiveness.Battery Protection: Some batteries have built-in protection mechanisms that halt charging when issues arise to prevent safety hazards.

It is advisable to recharge the battery every 3 months if it has been fully charged and remains unused for an extended period. This helps maintain its health and prevents performance degradation.

The recommendation depends on the specific circumstances. Generally, it's advisable to rotate the use of batteries, meaning to alternate between different batteries to ensure they all receive adequate charging and usage. This helps balance the lifespan and performance of the batteries.
On the other hand, if a device requires the simultaneous use of multiple batteries, it's important to use batteries of the same type, specifications, and similar age to ensure optimal performance and stability when used together.

This indicates that during the conversion of electrical energy into usable power for the battery, 80% of the electrical input is effectively utilized, with the remaining 20% possibly transformed into heat or other forms of energy loss.

It is advisable not to keep the charger powered on for a long period of time, as doing so can accelerate its aging process.

1. Installation Errors: A blinking red light or flashing error may indicate incorrect installation of the battery, leading to a short circuit.
2. Battery Placement and Condition: Incorrect battery placement, a damaged battery, or attempting to charge a non-rechargeable or incompatible battery can trigger a flashing red light or an ERROR.
3. Extended Charging Period: Leaving the battery in the charger for an extended period without removal may also cause the charger to flash a red light or display an ERROR.

For the battery charger featuring a USB cable input, this might indicate a low adapter current. To address this, connect a 5V/2A adapter for optimal charging performance, as outlined in the manual.

No, battery chargers equipped with a discharge function incorporate a cut-off voltage mechanism. This feature halts the discharge process once the batteries reach the specified voltage, mitigating the risk of over-discharge.

This indicates that during the conversion of electrical energy into usable power for the battery, 80% of the electrical input is effectively utilized, with the remaining 20% possibly transformed into heat or other forms of energy loss.

It is advisable not to keep the charger powered on for a long period of time, as doing so can accelerate its aging process.

Log in to your Doucalcell Official Account, click ‘My Account’, then select ‘My orders’ in the pull-down menu.

As orders usually start processing within one business day, if you need to cancel your order, modify your product or change your shipping address, please contacting us within 24 hours of placing your order

Canceling an order is one of the last things we want to do, but we have to do it for several reasons：

1) Item is out of stock.

2) Undeliverable areas.

3) Your financial institution did not allow the transaction.

4) The order is identified as a fraudulent order.

To get more personalized information about cancellations please feel free to email at doucalcell.store@doucalcell.com

If your order has not been shipped, please contact customer service support to cancel your order within 24 hours of the order time.However, the orders that have been shipped cannot be cancelled.

The code is invalid probably because it has expired or has not reached the minimum amount.

Go to page User Manuals and search for the product model to download the manual.

We accept the following forms of payment:

• American Express
• Discover
• MasterCard
• Visa
• Diners Club
• PayPal
• Google Pay
• Apple Pay
• Shop Pay

For your security, your billing name and address must match that of the credit card used for payment. We reserve the right to cancel any order that does not match these criteria.

Payment is taken during the checkout process when you pay for your order. The order number that appears on the confirmation screen indicates payment has been successfully processed.

For any technical difficulties you are experiencing with our website, please email us at doucalcell.store@doucalcell.com or contact us online, we will reply you within one business day.

We can ship to the continental United States. And we also deliver to Canada and Mexico as well as other countries. Please view more details in the Shipping Information page

Shipping is usually arranged within two to five days for products that are in stock.

For pre-sale products, please refer to the time noted in the product link.

For USA: Normally $2.99 for each package, free shipping on purchases over $15.

Shipping costs to Mexico and Canada depend on the weight of the product. Learn more details from the shipping information page.

USPS and UPS are our logistics partners to ship out Doucalcell products. We will choose the carrier that we think works best for our customers.

Our warehouse is in California and can deliver in 7 to 10 days for most areas, while Hawaii or more distant locations may take about 20 days for delivery.

Once your order is picked up by the carrier at our warehouse, we will send you a shipment tracking update email with the estimated delivery date and tracking number.

If you believe your order should have shipped but you did not receive the email, please check your junk email, or contact us.

We try to make sure all your items reach you at the same time. Sometimes our products are not always sent together since different shipping options can be used,depending on the product. Once an item has been shipped,you will receive a shipment notification email.

Unfortunately, we cannot change the shipping address once the product is in transit.

If your order is still under the estimated delivery time frame, kindly wait patiently. Once this process has been completed, you will see tracking updates.

If your order has not been updated for a long time and is overdue, you may contact the shipping courier or contact us for help.

All product deliveries are arranged by the logistics company. If the tracking information shows "delivered" but you have not received your package, please contact USPS or UPS promptly. And you can also contact us if you have any questions.

Please check the outer packaging of the courier for damage and send us photos of the outer packaging of the courier. We will promptly b any products that are damaged or lost in transit.

Please contact us and tell us what product you received. If an error product is shipped by the warehouse while processing your order, we will arrange for a replacement of the correct product for you and create a return label for you to return the wrong product.

1) Returns must be made within 30 days of purchase.
2) Products must be unused and in good condition with all packaging attached.
3) Refunds will be processed within 3-5 business days after we confirm receipt of your returned package.

For product issues, we will cover the postage; for non-product issues, the customer will cover the shipping costs.

Once received, returns are processed within 7–10 business days. The time to post a credit to your account can vary and is determined by the issuing bank. Please contact the issuing bank for details.

To obtain warranty service, please send your order number and contact our customer service team at doucalcell.store@doucalcell.com. We will get back to you within one business day.

We will take care of all quality-related issues with a REPLACEMENT or FULL REFUND including any return shipping costs.

Warranty excludes:

1) Damage caused by misuse the faulty parts.(including static discharge).

2) Improper installation.

3) Damaged by yourself.

4) Purchase the product by mistake.

5) Neglect, accident or modification, which was welded or changed during the assembly process.

6) Complimentary products.

Firstly, click on My account to access your personal information. Secondly, click on Forgot your password?, and submit your email address then we will send you an email with instructions on how to reset your password.


If you do not receive the e-mail, please check your spam folder and social tabs. If you still do not receive the email, please try again using a different browser or contact us via email (our service email is:d
oucalcell.store@doucalcell.com)

You can contact our customer service via email: doucalcell.store@doucalcell.com, tell us your name or phone number and we will help you find it.

You also have the option of being able to create a new account.

You can follow below 2 ways to add a new shipping address:

1. Find the address book, you will see all the addresses that have been added, then add the address.

2. Add a new shipping address to the checkout page.