The bz5 battery model name appears as B-Z5 on the cell, and most listings link it to the vivo Y36, Y78 5G, Y27 (4G) and Y27s. B-Z5's listing reads 5000 mAh typical, polymer, 3.89 V, which comes to 19.45 Wh. The maker group is Vivo.
People also type it as BZ5 or B Z5, and all three mean the same short Vivo code: the letter B, a hyphen, then Z and 5. B-Z5 names the vivo group rather than a single phone, so use the list below and then read your old cell before ordering. Your own model number decides the match, and some listings add a 5G Y27 that other listings leave out.
Quick facts
Step by step
Find your exact phone and model number
Open Settings, then About phone, and write down the handset name along with its model number. If you cannot see it, type model in the Settings search bar. A technician will also read it from the box.
Ask for the old pack to be read first
With the back panel open, look for
B-Z5next to the capacity and voltage on the cell label. Do not pull or peel the pack yourself.Compare the new pack side by side
The new pack should show B-Z5, a capacity close to 5000 mAh and the same connector shape. Hold both packs together and check size and thickness.
Test weight and print before fitting
Look for sharp print, a batch detail and a weight near the old pack. A feather-light pack that claims a huge capacity should be refused.
Phones that use the BZ5 battery model name
Vivo codes follow a short pattern, so B-Z5 only says the pack is a Vivo one. For the exact phones, most spare part listings agree on four names, all in the Y series. Model numbers are not confirmed here, so read yours under About phone and compare.
| Phone | Model number | Note |
|---|---|---|
| Vivo Y36 | Not confirmed | Listed for the 4G version; one listing adds 5G |
| Vivo Y78 5G | Not confirmed | Listed at 5000 mAh and 3.89 V |
| Vivo Y27 (4G) | Not confirmed | Listed in parts catalogues |
| Vivo Y27s | Not confirmed | Listed in parts catalogues |
| Vivo Y27 5G | Not confirmed | Only one listing names it, so check the label |
If your vivo is missing from this table, do not guess B-Z5 from its name. Look at the old cell label or search the code on the full Vivo battery code list.
Capacity of the B-Z5 battery: typical, rated and watt hours
The 5000 mAh figure is a typical value, quoted in sales text and parts lists. vivo labels often show a rated floor a little below 5000 mAh, so read your own B-Z5 rather than a listing.
B-Z5's energy is 5000 times 3.89, over a thousand, in watt hours. That gives 19.45 Wh for B-Z5. A Y27 cell at a different voltage would hold different energy even at 5000 mAh, which is why mAh alone misleads.
Real use depends on the chip, screen, signal and apps, and charging speed depends on the charger. With B-Z5, a Y36 or Y27 usually lasts a full day of ordinary use, though heavier habits shorten that.
Y36 and Y27 owners: two phones, one pack, one trap
These phones look alike, have similar names and sell in the same price band, so counters often mix them with other Y models. Y27 and Y27s are distinct handsets, like every other Y model, so check the full box name.
A customer brought a Y27s that lasted only half a day. The shop first offered a pack picked from the phone's size, which carried a different Vivo code. With the Y36 open, the technician read B-Z5 on the old cell and turned the other pack away. The fit was right only after the code matched.
Another trap is the variant. Some listings treat the Y36 4G and a Y36 5G as one battery family, yet a few sellers mention only one of them. Read your model number under About phone and compare it with what the seller writes.
vivo codes people confuse with B-Z5
Vivo codes are short, so one wrong letter points to a different phone. Print is small and the letters Z, S and E blur when a label is worn. Each code below fits its own phones, so check its page before accepting a pack printed with it.
- B-S2 and B-E5 are close in look but have their own phones.
- B-O5 is often typed as B05 or BO5, much like B-Z5 is typed BZ5. Different codes, different packs.
- B-Y1 and B-X8 also start with B and a nearby letter, so check each digit as well.
Phone pages such as Vivo Y20 and Vivo Y16 give the code for those phones. Check there, even if the names look close.
Signs your B-Z5 pack is wearing out
| Y36 or Y27 sign | Usual cause | B-Z5 step |
|---|---|---|
| Y36 loses a third in an hour of light use | Tired B-Z5 or heavy background apps | Close apps, then test battery health |
| Y27 switches off while 15 to 30 percent remains | B-Z5 cannot give peak current | Have B-Z5 tested |
| Y36 back panel or screen edge lifting | Puffed cell | Unplug it and visit service today |
| Handset stays warm when unused | A tired B-Z5, bad cable or stuck app | Restart the Y27, drop its cover, test B-Z5 |
Poor signal and busy apps often cause fast drain, so first read about what drains a phone quickly. Then see how to test battery health and decide whether a new pack is needed.
B-Z5 can catch fire once it swells, overheats, leaks or is dented. Unplug the Y36 immediately, do not bend or pierce it, and move it from anything warm. Cheap B-Z5 copies often print far above 5000 mAh, so accept only B-Z5 as the code.
Fitting a new B-Z5 pack the safe way
The Y36 and Y27 are sealed phones, so opening them needs heat, tools and care. vivo service or a well known repair counter should do it. Tell them your model, and have them compare B-Z5 with the old cell before work starts.
Spotting a poor copy is easier with the pack in your palm:
- It is noticeably lighter than the Y36's old cell.
- B-Z5 lettering smudges and there is no batch detail.
- The claimed capacity is far beyond 5000 mAh for the same size.
- The connector looks different or the pack is thicker than the old one.
See our fitting guide for sealed phones.
Snap the outgoing B-Z5 label before the cell is thrown out. If the replacement fails, you still have the code and batch details.
Daily care for B-Z5 in a vivo Y phone
On a Y36, most B-Z5 wear comes from warmth and nights left at full charge. Put the Y27 on a firm table to charge, clear of cushions and sun, and remove a bulky cover once it warms.
The Y36 comes with a 44 W charger; use it or a matching one, and retire any lead that heats at the plug. Unplug when the phone is full if you can. Should the Y78 5G keep cutting out early despite a restart and full charge, get B-Z5 tested first.
Frequently asked questions
Which phones carry the bz5 battery model name?
Most listings tie B-Z5 to the vivo Y36, Y78 5G, Y27 (4G) and Y27s. B-Z5 is listed at 5000 mAh typical and 3.89 V. Read the B-Z5 label on your old cell to confirm.
Is B-Z5 the same as BZ5 and B Z5?
Yes. People type bz5 or B Z5, but the cell prints B-Z5. Use the full written form when you ask for a replacement.
How many mAh is the B-Z5 battery?
B-Z5 is sold at 5000 mAh typical. Your B-Z5's rated minimum may be a little lower; read the label.
Is the B-Z5 battery the Vivo Y27 battery model?
Listings give it for the Y27 4G and the Y27s. One listing also names a Y27 5G, which others do not. Match your model number before ordering.
Can I use another 5000 mAh Vivo battery in place of B-Z5?
Not safely. Another 5000 mAh vivo code may differ from B-Z5 in size or plug. Compare the full B-Z5 code and plug shape.
How do I spot a counterfeit B-Z5?
Fake B-Z5 cells feel lighter, look smudged, lack batch details and claim well past 5000 mAh. Compare weight and print against the Y36's original.