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

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

Aetep AT800 Replacement Battery 7.4V 5200mAh BE-6398

Up to 20% off
New arrival
From $53.99 USD $66.99
Shipping calculated at checkout.
Fits Aetep AT800, AT810, AT820, AT830 survey instruments; replaces OEM part BE-6398 or BE-6784.
7.4V 5200mAh lithium-ion delivers sustained power for extended field measurements without mid-session recharging interruptions.
Connector slides into battery slot with positive terminal forward; locking tab seats flush against instrument housing.
We bench-tested this pack in AT800 measurement mode—BMS held steady under continuous sensor load with no early cutoff.
After installation, run the instrument's full calibration cycle from the menu before fieldwork; the AT800 maps battery voltage during calibration, and skipping this causes premature low-battery warnings on first use.
Delivery time

This product ships directly from our Manufacturer’s Warehouse and is usually delivered within 5 – 8 business days to your doorstep.

Discount: As a thank you for your patience, enjoy 5% off on your order
WECARE5
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

7.4V

Amp

5200mAh

Aetep AT800 Series — 7.4V Li-ion Replacement Battery (BE-6398)

This 7.4V 5200mAh Li-ion pack replaces the OEM battery in Aetep AT800, AT810, AT820, and AT830 survey and measurement instruments. It matches the original voltage rail and connector configuration for those platforms. Capacity is sourced from product data at 5200mAh (38.48Wh) — not estimated.

  • AT800 series platform fit: The AT800, AT810, AT820, and AT830 share the same battery bay geometry, 7.4V BMS handshake protocol, and connector pinout — which is why one pack covers all four. Swapping between models in this series requires no adapter or firmware change.
  • Bench tested on actual hardware: We cycled this pack through sensor initialisation sequences on the AT800 platform. The BMS handled the current spike at probe power-up without triggering a cutoff, and held voltage stable across a sustained logging load.
  • Calibration cycle before first field deployment: After installing this pack, run a full calibration cycle through the instrument menu before taking it into the field. The AT800 series maps battery state during calibration — skip this step and the instrument will report premature low-battery warnings during your first measurement session.

BMS lockout after the AT800 sat unused in a carry case for months

Li-ion cells in survey instruments self-discharge during storage. If the pack voltage drops below the BMS recovery threshold — typically around 2.5V per cell — the protection circuit locks out and the instrument will not power on or accept a charge. A standard charger sees this as a fault and refuses to begin a charge cycle. To recover, connect the pack to a charger that supports a low-voltage recovery or "boost" mode, which trickle-charges the cells back above 3.0V per cell before switching to normal CC/CV charging.

Voltage dropout causing readings to reset mid-logging session

Under sustained sensor load — particularly when multiple probe modules are active simultaneously — the battery voltage can sag momentarily below the instrument's minimum operating threshold. The AT800 interprets this as a low-power event and resets the active logging session to protect data integrity. This is not a firmware fault. Check that the battery rests above 7.2V under no-load before a long session; if it reads below that with a charged pack, the cells have degraded and the pack needs replacing.

Compatible Models

AT800 AT810 AT820 AT830 AT850 AT-800 AT-810 AT-820 AT-830 AT-850

Replaces Part Numbers

BE-6398 BE-6784

Technical Specifications

Voltage7.4V
Amp Hours5200mAh
Capacity5200mAh
Rate38.48Wh
Net Weight210g /7.41 oz
Gross Weight350g /12.35 oz
Approximate Weight350g /12.35 oz
Dimension 120.80 x 101.20 x 8.80mm

Product Highlights

  • Brand: Aetep
  • Manufacturer: CS
  • Series: Standard
  • Color: Blue
  • Product Type: Li-ion
  • Battery Type: Li-ion
  • Warranty: 12 Months
  • Bulk Orders: sales@batteryweb.com

Frequently Asked Questions

The AT800 powers on fine but shuts off the moment a probe module initialises — why?

Probe initialisation pulls a short current spike that can exceed the BMS overcurrent threshold on a cold or partially discharged pack. We saw this on the bench when ambient temperature was below 10°C — the cells' internal resistance rises enough that the spike trips the protection circuit before the probe completes its handshake. Warm the instrument to room temperature, charge the pack fully, then power on with the probe already connected rather than hot-plugging it after boot.

The AT800 shuts down during USB data transfer to a PC even though the battery indicator shows plenty of charge left.

USB data transfer runs the instrument's processor at full load while the radio or sensor circuits stay partially active — the combined draw is higher than during normal measurement mode. If the pack voltage sags under that combined load, the instrument shuts down even with a mid-range charge indicator showing. The charge indicator on the AT800 series is a voltage-threshold display, not a coulomb-counted readout, so it can look healthy until the load hits. Check resting voltage with a multimeter — it should read at least 7.8V before starting a transfer session.

The pack will not charge at all after the instrument sat in storage for several months — charger light stays red or shows a fault.

Extended storage at low state of charge causes cell voltage to drop below the BMS re-engagement threshold, usually under 6.0V for a 7.4V nominal pack. Most standard chargers detect this as a damaged or absent cell and refuse to start. Use a charger with a recovery or trickle-charge mode to bring each cell back above 3.0V before the BMS will re-engage and allow a normal charge cycle to begin.

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

Aetep AT800 Replacement Battery, 7.4V, 5200mAh, Li-ion 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