Welcome to our store. Your trusted source for batteries and power solutions. Learn more

For support or quotes: sales@batteryweb.com
WELCOME5
BatteryWeb

NTK Submarine Laptop Replacement Battery DR36 12V 3800mAh

Up to 19% off
New arrival
From $89.99 USD $110.99
Shipping calculated at checkout.
Fits NTK Submarine notebook and replaces OEM part numbers DR36 and DR36S battery packs.
12V, 3800mAh (45.6Wh) Ni-MH chemistry restores full capacity on this portable system.
Connector type and orientation match the original DR36 slot — no adapter needed.
We bench-tested this cell on a Submarine unit; BMS accepted the pack on first insertion and charged to full without cutoff errors.
After install, run one full discharge to hibernate shutdown then charge uninterrupted to 100% — this resets the BIOS battery learn cycle and clears false "poor health" warnings that appear after every cell swap.
Visa Mastercard American Express PayPal Apple Pay Google Pay Shop Pay Discover Klarna Afterpay Stripe
✦

Check that your old battery model number and device model to match our description. This makes sure they work together.

✦

We ship your order same day if you buy it before 4 PM EST.

Warranty

Let customers speak for us

from 11 reviews

Product is exactly as described and arrived quickly

Robert Jones
Rocket ES4-12 Compatible Replacement Battery

It took a bit longer than expected, likely due to the holiday season, but that was understandable. So far, the battery seems to be working well!

Linda M.
MGE UPS Systems Pulsar EX 1500RT Compatible Replacement Battery By Bright Way

Excellent substitute for the original, appearing to be the perfect replacement.

Alberto J.
APC SMART-UPS RT SURTA3000RMXL3U UPS High Performance Replacement Battery Set

It was what i was looking for. Support is fast

Jaswal
WAHEGURUG - RADHASWAMI

Fast service

Mark Casias
BatteryWeb

Perfect fit

Mark Casias
STX20L-BS Battery for Harley Softail FLS FLST 1991-2017 High Performance

Works Perfectly!!

Ben Benson
Invacare 220 Scooter High Performance Medical Replacement Battery Set

Send Your Battery Photo

Expert Technician Help

Snap a photo or video of your battery and send it to us. We'll identify the exact replacement—fast and hassle-free. Our team has helped thousands of customers find the right battery quickly and easily.

POST YOUR BATTERY IMAGE
Product & Solutions Expert

Product & Solutions Expert

✉ sales@batteryweb.com

🔹 10+ Years Battery Experience 🔹 Fast & Accurate Identification

Battery Care Tips

🔹 Getting Started

Charge your new battery fully before you use it for the first time. Over the next few charge cycles, run your device down to around 20% before you recharge—this helps the battery perform its best. After that, charge whenever you need to.

🔹 Keep It Healthy

Avoid letting your battery completely drain or staying plugged in constantly. Both extremes wear it out faster. Store the battery in a cool, dry place when you're not using it, since heat damages batteries quickly.

Delivery and Shipping

🔹 Most orders ship the next day, and we use FedEx, UPS, Purolator and other carriers to get them to you. Lithium batteries have to ship by ground only, not air or USPS. Make sure your address is right before you order, because if we have to send it back, you pay for shipping again.

Disclaimer

⚠️ Disclaimer: All product names, trademarks, and registered trademarks belong to their respective owners.

🔹 We use these names, brands, or model numbers only for identification and compatibility purposes.

Voltage

12V

Amp

3800mAh

NTK Submarine — 12V Ni-MH Replacement Battery (DR36)

This is a 12V, 3800mAh Ni-MH replacement battery for the NTK Submarine notebook. It fits the Submarine series and uses OEM part numbers DR36 and DR36S. Capacity matches the original cell at 45.6Wh — no modification required to install.

  • NTK Submarine compatibility: The DR36 and DR36S share the same 12V rail, physical connector, and BMS handshake as the original Submarine battery pack. Both part numbers refer to the same cell configuration, so either OEM reference confirms the correct fit.
  • Bench tested on actual hardware: We cycled this cell through charge and discharge under a controlled load. The BMS responded correctly at both low-voltage cutoff and full-charge termination — no false trips or runaway charge events observed.
  • First-cycle calibration on the Submarine: After installing, run one full discharge to hibernate-cutoff, then charge uninterrupted to 100%. Ni-MH cells require this to let the fuel gauge IC reset its baseline against the new cell — skipping it causes the BIOS battery health warning to persist after the swap.

Why the Submarine's BIOS flags poor battery health after a cell swap

The Submarine stores battery health data in EEPROM on the original pack. When a new cell goes in, the BIOS reads stale data from its own records and reports poor health — not a fault with the replacement. Running the battery learn cycle (full discharge to cutoff, uninterrupted recharge to 100%) forces the BIOS to re-evaluate and overwrite that cached health state. Until the cycle completes, the health warning is expected and does not indicate a defective cell.

Submarine shutting down at 20–30% battery shown

This symptom means the fuel gauge IC has not yet calibrated against the new cell's voltage curve. The OS reads a percentage based on old calibration data, so the cell hits its actual low-voltage floor while the display still shows 20–30% remaining. The laptop shuts down because the cell voltage drops below the BMS cutoff threshold — not because the battery is faulty. Run two full discharge-to-cutoff and recharge cycles; by the third cycle the gauge IC re-maps the curve and the reported percentage aligns with real capacity.

Compatible Models

submarine

Replaces Part Numbers

DR36 DR36S

Technical Specifications

Voltage12V
Amp Hours3800mAh
Capacity3800mAh
Rate45.6Wh
Gross Weight150g /5.29 oz
Approximate Weight150g /5.29 oz
Dimension 139.50 x 89.00 x 20.00mm

Product Highlights

  • Brand: NTK
  • Manufacturer: CS
  • Series: Standard
  • Color: Black
  • Product Type: Ni-MH
  • Battery Type: Ni-MH
  • Warranty: 12 Months
  • Bulk Orders: sales@batteryweb.com

Frequently Asked Questions

The NTK Submarine shows the new battery as "0%" or "unknown" in the OS — is the cell dead?

No. The OS fuel gauge IC is reading EEPROM data left over from the old pack and has not yet mapped the new cell's voltage curve. Run a full discharge to hibernate-cutoff followed by an uninterrupted charge to 100%. After one complete learn cycle the OS will recognise the cell and display an accurate percentage.

System information shows the wrong Wh rating after installing the DR36 replacement — it doesn't match 45.6Wh.

The Wh figure shown in system info pulls from the EEPROM on the original pack, not a live reading of the new cell. Until the BIOS completes a full battery learn cycle, it displays the cached rated value from the previous battery. Run one full discharge to cutoff and recharge to 100%; the BIOS then recalculates and updates the Wh figure against the actual cell chemistry.

The Submarine's charge stops at around 80% and won't go higher — what's blocking it?

Some BIOS firmware versions on this platform include a charge-limit feature that caps charging at 80% to reduce cell wear during long AC-connected use. Check the power management settings in the BIOS or the NTK utility software and disable the battery charge threshold. Once the limit is cleared, the cell will charge to 100%.

Payment & Security

Payment methods

  • American Express
  • Apple Pay
  • Diners Club
  • Discover
  • Google Pay
  • Mastercard
  • PayPal
  • Shop Pay
  • Visa

Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.

Related Products

Clevo PortaNote 982A Replacement Battery, 12V, 3800mAh, Ni-MH 1

Engineered for Performance. Built to Last.

Check out our top-rated selection of reliable products built to last. We offer high-quality options that deliver consistent performance for all your needs.

Our Collections