Written B-T7 on the cell, the BT7 battery model name is a vivo code listed mostly for the vivo Y21e. The Y21e has a 5000 mAh typical battery, and that is the figure to expect for this pack. One listing adds the vivo Y32, unconfirmed, so treat B-T7 for the Y21e as a strong lead and read the label first.
People type this code as BT7, B-T7 or "vivo bt7 battery". The second character is the letter T, and the last is the digit 7, which is easy to misread on a worn sticker. B-T7 is printed on the cell, so the sealed Y21e must be opened by a technician before anyone can read it.
Quick facts
Step by step
Write down the phone name and model number
Open Settings, tap About phone and note the name and model number. If you cannot find it, type model in the Settings search bar.
Have the old sticker read with the back open
A technician should lift the back panel and read the line that says
B-T7. Please do not pull or pry the pack out yourself.Photograph the sticker before anything is thrown away
Take a clear picture of the whole label, including the capacity and any batch line. It settles every doubt later.
Compare the new pack with the old one
Put both packs side by side. The code, the connector shape and the size should agree, and the weight should be close.
Which phones use the BT7 battery model name
The B at the start tells you the pack belongs to the Vivo and iQOO group. It does not name a phone. For B-T7, most listings point to the Vivo Y21e. One listing also names the Vivo Y32, but that match is not confirmed. Both are budget phones with a 5000 mAh class battery, but a similar capacity does not prove a shared pack.
| vivo handset name | Status | What to do |
|---|---|---|
| Vivo Y21e | Most B-T7 listings name it | Check the old B-T7 sticker |
| Vivo Y32 | Named in one listing only | Treat as unconfirmed, read the sticker |
| Vivo Y21 and Y21 New | Not confirmed for B-T7 | Use the phone's own page |
| Vivo Y33s | Not confirmed for B-T7 | Use the phone's own page |
Vivo sold several phones with names that differ by one letter or one word. The Vivo Y21 New page deals with that phone separately, so do not carry its code over to the Y21e.
Reading the code on the label without a mistake
On the cell, the code is written with a hyphen as B-T7. Search boxes drop the hyphen, so you will also see BT7. Some people type B07 or B17 because the T and the 7 are thin and close together on a small sticker. Those are different strings and could be different packs.
- Check that the second character has a flat top bar. That is a T, not a 1 or an I.
- Check that the last character has a bent stem. That is a 7.
- If the B-T7 print is faint, angle it under a strong light or ask for a close photo.
Write the code in capitals with the hyphen on your note. A counter assistant then has no room to hear "B-D7" or "B-E7" when you say "bee tee seven".
Capacity: the 5000 mAh figure and your own label
B-T7's 5000 mAh is the typical figure on Y21e spec sheets. A battery sticker usually prints a rated (minimum) value as well, and that number is a little lower. Your pack may show it, and the lower number is not a fault. Read it off your own label instead of trusting a listing.
Some online listing pages show wild capacity numbers for this pack, far below or far above 5000 mAh. Ignore such figures. A phone built around a 5000 mAh cell cannot honestly take a pack that is much bigger in the same space. The voltage and the watt hour figure also sit on the label, so use those for any energy comparison.
Y21e runtime depends on its chip, screen, signal and apps, so the same B-T7 can last differently for two owners.
Checking B-T7 before you pay
Follow these steps in order; the Y21e name alone is not enough for vivo cells.
- Copy the Y21e model number from About phone or its box.
- Get the old sticker read, and compare it with
B-T7letter by letter. - Ask for the connector and the pack size to be compared with the old one.
- Accept the pack only if all three agree.
A Y21e owner asked for a "B-T7" and was handed a pack marked B-S7, said to be "the same family". Side by side with the old cell, the technician spotted a different code and a plug in another position. The right pack was ordered the next day. The same-looking codes cost one day, not a damaged board.
Failing battery signs and what each one means
| Y21e symptom | Behind it | B-T7 step |
|---|---|---|
| Charge drops in a few hours | Cell has worn out over many cycles | Check Y21e health, then plan a B-T7 |
| Y21e cuts out between 15 and 25 percent | Tired B-T7 cannot give peak current | Ask vivo service to measure B-T7 |
| Y21e screen lifts or back bulges | B-T7 has swollen | Unplug the Y21e and go today |
| Y21e warm while idle | Worn B-T7, or an app running hot | Restart the Y21e, remove its cover, test B-T7 |
Before blaming B-T7, rule out apps and signal on the Y21e with our drain advice. The battery health check then shows whether the cell itself is the cause.
B-T7 becomes a fire hazard once it swells, heats, leaks or is dented. Take the Y21e off charge, keep it unbent, let it cool and bring it to vivo service. B-T7 copies often exaggerate capacity, so ask for B-T7 by name.
Fitting a replacement the safe way
The Y21e has a sealed body. The Y21e opens only with heat, tools and care, and one slip can puncture B-T7. Choose vivo service or a reputable shop, give them the Y21e model number and have them match B-T7 to the old sticker.
Inspect a new B-T7 before fitting:
- It feels lighter than the Y21e's original.
- The B-T7 lettering smudges and carries no batch line.
- It claims a capacity well beyond 5000 mAh.
Any one of these is a reason to refuse it. Wider fitting advice is collected in mobile battery replacement.
vivo codes people confuse with B-T7
Vivo codes are short, so many differ by a single character. B-S7 shares the 7 at the end, and B-O5 is another common one that gets typed in three ways. Each has its own phone list, and none of those lists can be borrowed for B-T7. All vivo and iQOO codes are gathered in our vivo code list.
Two packs of equal mAh can still differ in shape, connector and voltage, which is why a matching capacity alone proves nothing.
Frequently asked questions
Which phone carries the BT7 battery model name?
Most sellers connect B-T7 to the vivo Y21e. One listing adds the vivo Y32, unconfirmed. Read B-T7 on your old cell before ordering.
Is B-T7 the same as BT7?
Yes. B-T7 is the proper form on the label, and BT7 is how people type it without the hyphen. Do not confuse either with B07 or B17.
How many mAh is the Vivo B-T7 battery?
B-T7 sells as a 5000 mAh typical cell. Your Y21e's B-T7 may print a rated figure slightly under 5000 mAh.
Can I fit a B-S7 battery in place of B-T7?
Do not assume so. One character separates B-T7 from its neighbours, and plug and size may differ. Match the full code.
Does the Vivo Y21 use the same battery as the Y21e?
Not confirmed. The names are close, but phones in the Y21 range have been sold with different packs. Check the code on its label.
What gives away a counterfeit B-T7?
Fake B-T7 cells are light and blurry, with no batch line and claims beyond 5000 mAh. Compare weight and B-T7 code with the Y21e's original.