BYD Dolphin charging at home, illustrating that its LFP Blade battery is designed to be charged to 100 percent

BYD Dolphin Blade Battery: LFP Chemistry, Capacity and Care

The BYD Dolphin uses a Lithium iron phosphate (LFP) Blade battery, rated at 135 Ah on the Standard Range and 150 Ah on the Extended Range. Because it is LFP chemistry, the usual 20 to 80 percent charging rule does not apply. In fact, the owner's manual recommends fully charging the Dolphin to 100 percent at least once a week. LFP is a safe, durable chemistry that is happy at a full charge.

BYD Dolphin Battery at a Glance

Measurement Standard Range Extended Range
Chemistry LFP Blade LFP Blade
Rated capacity 135 Ah 150 Ah
Usable energy (market) About 44.9 kWh About 60.5 kWh
Charge to 100 percent regularly 100 percent regularly
20 to 80 rule Does not apply Does not apply
Battery warranty 8 years or 160,000 km

What Is the Blade Battery?

The Blade battery is BYD's own design, and it is one of the Dolphin's standout features. It uses Lithium iron phosphate chemistry, known as LFP, arranged in long, thin cells shaped like blades.

This gives it two big advantages. LFP is inherently more stable and safer than the nickel-based chemistries in many rivals, and the blade shape packs cells efficiently, freeing up space and improving strength.

  • Safe: LFP is highly resistant to thermal runaway, the overheating risk that affects some battery types
  • Durable: LFP cells typically tolerate more charge cycles over their life
  • Cobalt-free: The chemistry avoids cobalt, which is better for cost and ethics

Capacity: Ah Versus kWh

There is an important distinction in how the Dolphin's capacity is described, and it is worth being clear about it.

The owner's manual lists the battery by its rated capacity in amp-hours: 135 Ah for the Standard Range and 150 Ah for the Extended Range. The energy figures people usually quote, around 44.9 kWh and 60.5 kWh, come from market specifications rather than the manual itself.

Both describe the same batteries. The amp-hour rating is the manufacturer's official figure, while the kilowatt-hour numbers are the more familiar way to compare range and charging between cars.

Why the 20 to 80 Percent Rule Does Not Apply

This is the single most important thing to know, and it is where the Dolphin differs from many electric cars. You may have heard that you should keep an EV battery between 20 and 80 percent to preserve its health. That advice is for nickel-based batteries, not LFP.

The Dolphin's LFP Blade battery is designed to be charged fully. The owner's manual actively recommends it, advising you to fully charge the vehicle at least once a week, and to fully charge it from a low state of charge, below 10 percent, once every three to six months.

  • Charge to 100 percent: Regular full charges are recommended, not avoided
  • Weekly full charge: The manual advises topping to 100 percent at least once a week
  • Occasional deep cycle: A full charge from below 10 percent every three to six months helps
  • Why it helps: This keeps the battery's charge estimate accurate, so your range readout stays reliable

So if you have been babying your Dolphin's battery by stopping at 80 percent, you can relax. Charging it fully is exactly what BYD recommends.

Healthy Charging Habits

A few simple habits keep your Blade battery in top condition for the long haul.

  • Charge fully and often: Regular 100 percent charges suit LFP, unlike other chemistries
  • Do the periodic deep charge: Run it low and charge fully every three to six months to recalibrate
  • Use AC for daily charging: Home AC charging is gentle and ideal for everyday top-ups
  • Save DC for trips: Rapid DC charging is great on the road but not needed daily
  • Mind the cold: In low temperatures the battery holds less usable energy, and the charge reading may jump to 100 percent quickly, which is normal
  • Do not leave it flat: Avoid storing the car at a very low charge for long periods

Looking After Battery Life

LFP is a long-lived chemistry, and the Dolphin's battery is built to last the life of the car. A little care extends it further.

Temperature is the main factor. The manual notes that usable capacity drops in cold weather and returns as it warms, and that under harsh use the battery may reduce output to protect itself. None of this is a fault, it is the battery management system doing its job.

For a deeper look at how the Blade battery works, our full explainer on BYD's Blade battery covers the technology in detail, and our guide to battery lifespan and replacement cost on the Atto 3 puts longevity and value in context.

Battery Warranty

BYD backs the Blade battery with a strong warranty, reflecting confidence in its longevity.

The traction battery is covered for 8 years or 160,000 km, and BYD guarantees it will retain at least 70 percent of its capacity over that period. For most owners, that means the battery will comfortably outlast their ownership while still holding the great majority of its range.

Infographic showing BYD Dolphin Blade battery capacity, that LFP should be charged to 100 percent, and charging habits

Common Mistakes

  • Applying the 20 to 80 rule: That is for other chemistries, not the Dolphin's LFP Blade
  • Avoiding full charges: The manual recommends charging to 100 percent at least weekly
  • Skipping the deep cycle: A full charge from low every three to six months keeps the readout accurate
  • Worrying about cold-weather range: Reduced capacity in the cold is normal and temporary
  • Confusing Ah and kWh: The manual quotes amp-hours, while kWh figures come from market specs
  • Relying on DC daily: Everyday AC charging is gentler and all most owners need
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