SmarToools RB40 AAA 1.5V 750 mWh Rechargeable Battery (4Pcs Set)

The smartoools rb40 is a four-piece set of AAA rechargeable batteries that charges through a Type-C USB cable, according to the product listing. Check your device manual to see whether it takes AAA cells. Buyers in Bangladesh who use AAA devices at home can compare it with disposable cells before they order.

• Overview
• Key features
• Specifications
• How to use and set up
• Compatibility and what is in the box
• Who should buy it in Bangladesh
• Alternatives in our store
• Warranty and support
• Delivery, returns and ordering
• Frequently asked questions

Why the smartoools rb40 fits a Bangladeshi home

Batteries are one of those small household items that run out at the worst moment. Many homes use AAA cells in a remote for the ceiling fan, a wall clock, a torch kept near the door for load-shedding nights or a wireless mouse on a study desk. The smartoools rb40 is one option for people who would rather recharge AAA cells at home than buy disposables for those devices.

According to the listing, the figures are a nominal voltage of 1.5V, a capacity of 750mWh and a typical rating of 400mAh, and the material is listed as lithium-ion. Those are the figures to compare when you judge the smartoools rb40 against your current disposables. Rechargeable cells do not always match disposable ones in runtime or in how they handle heavy draw, so check that your device is happy with a rechargeable AAA cell before you commit to a full household set.

The listing says the smartoools rb40 set contains four pieces, so a household with two or three AAA devices could keep a spare on hand. It does not say how many charge cycles the cells are rated for, how long they keep their charge in storage, or how they perform in a hot room. Those points are not confirmed by the listing, so if any of them affects your decision, message us before you order.

Bangladesh adds its own conditions. Humidity during the monsoon can make storage boxes feel damp, and load-shedding can leave a household short of light when a torch is most needed. A set of rechargeable AAA cells can help you keep a torch and a clock ready, provided you can charge them when the mains is on. Plan that routine before you depend on the set for emergencies.

Capacity is listed as 750mWh, which is a milliwatt-hour rating, while the typical figure is listed as 400mAh. Compare both numbers when you look at other AAA sets, because a single figure can make two products look more alike than they are.

Key features

Lithium-ion rechargeable cells

The listing gives the material as lithium-ion. For a buyer, that means the cells can be recharged instead of thrown away after one use, which is the main reason to pick a rechargeable AAA set over disposables.

The listing does not name the devices it is intended for, so check your device manual. It also does not state a cycle count, so ask us if that figure matters to you. Store the smartoools rb40 cells in a dry place at room temperature, away from metal objects that could touch the terminals.

Type-C USB charging at 5V

The smartoools rb40 is listed with a Type-C USB cable as its charging method and a charging voltage of 5V. The parts to check before you plug in are therefore the cable and a 5V USB adapter.

The listing gives a charging time of 2 hours, plus or minus 0.5 hours, which is a useful planning figure. Plan a charge for a time when you will be at home to check the indicators. Keep the adapter in a ventilated spot, because humid months in Dhaka can make heat build up in enclosed spaces.

LED indicators

According to the listing, the LED indicators blink while the cells are charging and stay on when they are fully charged. That gives a simple visual check without a separate meter. The listing names the behaviour of the lights but does not describe a colour code, so do not assume one.

If the smartoools rb40 is still blinking well past the listed charging time, unplug it and check the cable and adapter before you blame the cells. A steady light after that point is the signal the listing describes for a full charge.

Protection features

The listing states protection against short-circuit, overflow, overcharge and over-discharge, marked as YES. In plain terms, these are safeguards intended to stop a cell from being pushed past safe charge limits or drained too far.

The listing does not name a protection circuit supplier or describe exact thresholds, so this page reports only what the listing states. A protected cell still needs sensible handling, so do not mix old and new cells in one device. The smartoools rb40 gives you these listed protections, but they do not replace careful use.

Compact size and light weight

The listing gives a diameter of min 9.8mm to max 10.5mm, a height of min 43.5mm to max 44.5mm and a weight of 6.9 grams, plus or minus 0.5 grams. These measurements matter most where the battery compartment is tight.

Because the diameter and height are given as ranges, a cell at the larger end may feel tight in some compartments. Measure the compartment before you order a bulk quantity. Compare these dimensions with the battery compartment in your own device, not in isolation.

Storage and handling

Good storage keeps a smartoools rb40 set ready for use. Keep the cells in their box or a small case so the terminals do not touch coins, keys or loose metal. Avoid leaving cells in a hot car or in direct sun, and keep them away from damp shelves in bathrooms or kitchens.

The listing does not describe a storage temperature range, so rely on common sense and normal room conditions. If a cell feels hot, swollen or smells unusual, stop using it at once and set it aside.

Specifications

The table below lists the specifications of the smartoools rb40 exactly as the product listing states them.

These are the listed specifications from the product listing for the smartoools rb40, and we have not added figures beyond them.

How to use and set up

Start by checking the set. Confirm that all four cells are present and that none is cracked, leaking or swollen before you use the smartoools rb40. Do not charge a damaged cell, and set it aside for safe disposal.

Plug the Type-C USB cable into a 5V USB adapter, then connect the cable to your charging point. The listing does not describe a charging unit, so follow the instructions that come with whatever unit you use, and do not leave cells charging unattended in a hot room.

Watch the LED indicators. According to the listing, they blink while the smartoools rb40 is charging and stay on when the cells are fully charged. Allow the listed time of 2 hours, plus or minus 0.5 hours, before you assume the set is ready, and check the indicators again before you remove a cell.

Insert each cell with the polarity marked on your device. Check the battery compartment before you close it, and never force a smartoools rb40 cell in the wrong way.

Before the first full charge, wipe the terminals with a dry cloth and check that the cells sit flat in the tray. Use the listed time as a guide, then check the indicators. Keep a note of the date you first charged the smartoools rb40 set so you can rotate cells in use.

Humidity is a real issue in Dhaka, so keep your smartoools rb40 cells in a closed box rather than on an open shelf during the rainy season. Store spare cells in a cool place away from metal objects that could touch the terminals, and label the box with the date of the last charge.

If a set will not charge, first try a different cable and a known-good 5V adapter. If the indicators still do not respond, stop using the smartoools rb40 cells and contact us with your order details. Do not try to open or repair a cell.

Plan charging around the power supply in your area. If the mains goes off during a charge, check the indicators once power returns before you assume the cells are full.

Checking the smartoools rb40 set once a month is a sensible habit, even if you have not used it. Look for leaks, check the terminals and confirm that the indicators respond when you connect the charger. This lets you spot problems before a device is left without power.

For general background on how chargers work, read the battery charger overview on Wikipedia.

Compatibility and what is in the box

Confirmed by the listing: the set is four AAA pieces, with a nominal voltage of 1.5V, Type-C USB charging at 5V and the dimensions shown in the specifications table. Those are the facts you can check against your device.

Not stated in the listing: which specific devices the smartoools rb40 is designed for, whether a charging cable or adapter is included, and whether the set suits devices that call for a particular battery chemistry. We have not added those claims. If your device needs a specific battery type, ask us before you buy.

Before you order, measure the battery compartment of your device, because the diameter and height are listed as ranges rather than single values. A device that lists AAA cells in its manual is the most straightforward match.

The smartoools rb40 is listed at 1.5V nominal, so compare that figure with the rating printed on any disposable cells your device uses now. Look also at the battery door or tray, which will show how many cells the device takes and in which orientation.

When you open the box, check the number of pieces against the four-piece listing before you start charging. If the set does not match, contact us with your order details before you use any cell.

Who should buy it in Bangladesh

Households that already use AAA cells in a ceiling fan remote, a wall clock or a torch may consider the smartoools rb40 for those devices. If those devices take AAA cells and you change them often, a four-piece rechargeable set can reduce how often you need to visit a shop.

Home offices with a wireless mouse or another small desk device may consider the smartoools rb40 if the device takes AAA cells. The compact diameter and light weight matter where the cell sits in a tight compartment, so measure first.

Small shops and cafes with counter devices, such as a handheld scanner or a wall clock, may consider the smartoools rb40 if the device takes AAA cells. Check the device’s own guidance on rechargeable use before switching.

Families with several AAA toys or children’s remote controls may also consider the smartoools rb40 4-pack. Keep the cells out of reach of young children, and supervise any charging.

Households that rely on a torch during load-shedding should charge the smartoools rb40 set during daytime or on a stable supply, so it is ready when the lights go off.

Students and renters who move often may also like a set they can take with them. If you already own a 5V USB adapter with spare capacity, you may be able to charge the smartoools rb40 with it. Check the adapter rating first.

Offices and classrooms that keep a box of spare AAA cells for shared equipment may find a rechargeable set easier to manage than buying disposables each term. Label the set so everyone knows which cells are charged and which are in use.

Buyers who need a different battery size, a phone battery or a multi-slot charger should look at the alternatives below rather than this set. Matching the product to the device is the step that saves the most trouble.

Alternatives in our store

Compared with the smartoools rb40, the SmarToools RB20 AAA 1.5V 750 mWh Rechargeable Battery (2 Pcs Set) is a two-piece AAA option. If you need a different size, see the SmarToools RB20 AA 1.5V 2600mWh Rechargeable Battery ( 2 Pcs Set). For a phone-focused option, see the Hoco J112 iPx Smart Li-Polymer 2716mAh iPhone X Battery, and for a multi-slot charger, see the Liitokala Lii M4S 4-Slot Multifunctional Battery Charger. You can browse the full range in Batteries & Chargers.

Choosing between sets comes down to how many AAA devices you run at once. The smartoools rb40 four-piece set gives you spares on hand, while a two-piece pack gives you two cells. Check the listed capacity on each product page before you compare.

Warranty and support

Warranty: 7 Days seller warranty.

Delivery, returns and ordering

For the smartoools rb40, the store policy is simple. We deliver all over Bangladesh and you pay cash on delivery. Delivery usually takes 1–3 days inside Dhaka city and 2–5 days outside Dhaka. You can return it within 7 days of delivery (see our Delivery & Returns policy). Questions before ordering: call 09638054751, message us on Facebook Messenger or email care@gadgetsuperb.com.

Check the full policy page before you place an order, because it sets out the conditions that apply to returns. The delivery times above are usual times rather than guarantees, so allow a little extra time during busy periods.

When you place an order, give a full delivery address and a phone number you can answer during the day, so we can reach you if the courier needs to confirm the address.

Before you check out, decide whether you need the four-piece set or a smaller pack, so the order matches your device list.

Frequently asked questions

What is the smartoools rb40?

The smartoools rb40 is a four-piece set of AAA rechargeable batteries, listed with a 1.5V nominal voltage and a 750 mWh capacity. The listing gives the material as lithium-ion and the charging method as a Type-C USB cable. Check your device manual to confirm it takes AAA cells.

Is the smartoools rb40 a 1.5V battery?

Yes, the smartoools rb40 is listed with a nominal voltage of 1.5V. The listing also gives a typical rating of 400mAh, but it does not name the devices it is intended for.

How long does the smartoools rb40 take to charge?

The listing gives a charging time of 2 hours, plus or minus 0.5 hours. Start charging when you can leave the set undisturbed, and check the indicators once the listed time has passed.

Does it charge through USB-C?

The listing names a Type-C USB cable as the charging method, with a charging voltage of 5V. Make sure your adapter is rated for 5V before you connect the cable.

What do the LED lights mean?

According to the listing, the LED indicators blink while the cells are charging and stay on when they are fully charged. If the lights behave differently, check the cable and adapter first.

Are the cells lithium-ion?

The listing gives the material as lithium-ion battery. It does not state a charge cycle count or storage life, so ask us if those figures matter for your use.

Can I use the smartoools rb40 in any AAA device?

Not every device is a match. Check that the device takes AAA cells and that its battery compartment fits the listed diameter of 9.8mm to 10.5mm and height of 43.5mm to 44.5mm.

Does the set come with a charger?

The listing names the charging method as a Type-C USB cable, but it does not say that one is included. Ask us before you order if you need to know what is in the box.

How long is the warranty?

Warranty: 7 Days seller warranty.

Can I return it if it does not suit me?

Yes, you can return it within 7 days of delivery, according to our Delivery and Returns policy. Check the policy page for the full conditions before you order.

Where can I ask questions before I order?

Call 09638054751, message us on Facebook Messenger or email care@gadgetsuperb.com. Include your device model so we can help you check the size question.

Should children handle the cells?

Keep the cells out of reach of young children and supervise any charging. The listing does not give child-safety guidance, so follow the sensible handling steps in this guide.