The BLP665 is the factory battery part number used for the Oppo Realme 1 and Oppo F7 Youth mobile phones. The BLP665 battery fits the Realme 1 and Oppo F7 Youth (CPH1859/CPH1861). See exact specs, mAh differences, and how to buy a genuine replacement in India.
If you popped open an old phone and found “BLP665” printed on the battery, you’re probably trying to figure out one thing fast: does this fit my phone, and where do I buy a real one? Let’s sort that out.
BLP665 is a battery model code used by Oppo, assigned to the Realme 1 and its close sibling, the Oppo F7 Youth (model numbers CPH1859 and CPH1861). It’s a 3.85V lithium-polymer battery. Capacity is listed differently across sellers more on why below.
Which Phones Use the BLP665 Battery?
Two phones, sold under two brand names, because Realme was still part of Oppo when this device launched in 2018.
According to Realme’s original India launch listing (Realme, 2018)[1], the Realme 1 shipped with a 3410mAh non-removable battery. That’s the same physical unit later branded and sold under Oppo’s model numbers for the F7 Youth variant.
| Phone Model | Battery Code | Capacity (Official) | Sold As |
| Realme 1 | BLP665 | 3410mAh | Realme (India, global) |
| Oppo F7 Youth | BLP665 | 3410mAh | Oppo (CPH1859) |
| Oppo F7 Youth variant | BLP665 | 3410mAh | Oppo (CPH1861) |
If your phone’s model number on the back or in Settings > About Phone shows CPH1859, CPH1861, or “Realme 1,” you’ve got the right match. Nothing else to check.
Some sellers also list this battery for “Realme One” — that’s not a typo or a different device. It’s just how Realme’s global vs India naming split in early listings.
BLP665 Battery Specs Explained
The spec sheet looks simple until you start comparing listings and the mAh number won’t sit still. You’ll see 3310mAh, 3400mAh, and 3410mAh across different sellers for what’s supposedly the same battery.
That’s not three different batteries. It’s rounding. Some manufacturers rate capacity at the cell’s rated (nominal) value, others at typical output, and a few round down for safety margin on replacement units. 3410mAh is the figure from Realme’s own launch spec sheet, so treat that as the reference number.
Full spec rundown:
- Voltage: 3.85V
- Chemistry: Lithium-polymer (Li-Po)
- Capacity: 3410mAh (official), listed as low as 3310mAh on some replacement units
- Weight: roughly 55-60 grams
- Removable: No it’s glued into the chassis, not a pop-out battery
I’ve seen conflicting numbers across ten-plus listings while researching this. My read: anything between 3300mAh and 3410mAh from a listed brand is within normal manufacturing variance. Anything above 3410mAh claimed by an unbranded seller is a red flag, not a bonus.
Original vs Duplicate BLP665 Battery: How to Tell
Most people assume a higher advertised mAh means a better battery. The data on replacement lithium cells says otherwise capacity claims above the original spec are one of the most common markers of a mislabeled or low-grade cell, because physically fitting more capacity into the same case usually means thinner protection circuitry.
What most guides selling these batteries skip: the safety certification, not the mAh number, is what actually protects your phone.
Check for these before buying:
- BIS certification mark or IS 16046 compliance printed on the battery
- A stated warranty of 3-6 months minimum from the seller
- Weight close to 55-60 grams suspiciously light units often have less lithium content than claimed
- A brand name on the cell itself (BatteryGod, Mobatree, Ticon, and similar are commonly sold in India) rather than a blank wrapper
Some buyers argue any cheap replacement is fine for an old phone they’re not attached to. That’s fair if you’re using the phone as a backup device for light tasks. But if it’s your daily driver, an uncertified battery that swells is a fire risk you don’t want to gamble on.
Where to Buy a Genuine BLP665 Battery in India
Prices for BLP665 replacements in India typically run ₹350-₹900 depending on brand and warranty length. Amazon.in, Mobatree, BatteryGod, and Indclues are among the sellers actively stocking this model as of 2026.
Boxtron vs Mobatree vs BatteryGod:
Boxtron and Mobatree ship India-assembled cells with 90-180 day warranties, better suited if you want documented after-sales support. BatteryGod leans on bulk pricing and faster shipping, which works better if you just need the phone running again this week and don’t need a long warranty window.
How to Replace a BLP665 Battery Safely
To replace the BLP665 battery in a Realme 1 or Oppo F7 Youth, follow these steps:
- Power off the phone completely before opening it
- Heat the back panel edges gently to loosen the adhesive
- Remove the back cover and disconnect the battery ribbon
- Peel out the old battery slowly stop if it resists
- Fit the new BLP665, reconnect the ribbon, and reseal the back
Quick note: if the old battery feels puffed or the back cover was already bulging outward, don’t heat it and don’t press on it. Take it to a repair shop instead a swollen Li-Po cell can rupture under pressure or heat.
FAQs About the BLP665 Battery
What’s the best replacement brand for a BLP665 battery in India?
BatteryGod, Mobatree, and Boxtron are the most commonly reviewed options, each offering 90+ day warranties and BIS-marked cells.
How do I know if my old battery is a genuine BLP665?
Check the printed code, weight (~55-60g), and BIS certification mark. Genuine cells rarely exceed 3410mAh.
Q: Should I buy a battery with a higher mAh than 3410?
No. Claims above the official spec on an unbranded battery usually indicate mislabeling, not extra capacity.
Why do listings show 3310mAh instead of 3410mAh?
Sellers round differently between rated and typical capacity both numbers can describe the same genuine battery.
When should I stop trying to replace the battery myself?
If the old battery is visibly swollen or the phone won’t power on after reconnecting it, stop and take it to a repair technician.
Conclusion
BLP665 battery fits the Realme 1 and Oppo F7 Youth (CPH1859/CPH1861) mAh differences, and how to buy a genuine replacement in India. BLP665 battery’s compatibility, specs, and safe replacement for Realme 1 and Oppo F7 Youth owners in India. It does not cover battery replacement for other Realme or Oppo models — those use different battery codes entirely.
- [1] StandPhill India — BIS IS 16046 (Part 2):2018 Certification Guide https://www.standphillindia.in/product/lithium-ion-cells-and-batteries.php