Battery Technology Inc.
Battery Technology Inc. IB-X40H 8-cell 4400 mAh 14.8 V laptop battery for ThinkPad X40 X41
An 8-cell lithium-ion battery delivering 4400 mAh at 14.8 V for ThinkPad X40 and X41 models
- TypeBattery
- CompatibilityLenovo ThinkPad Notebook Series: X40, X41
- Battery Type8 Cell Lithium-Ion
- Battery Voltage14.8V
- Battery Capacity4400 mAh
- FeaturesColor: Black
- 8-cell lithium-ion design delivers 4400 mAh capacity
- 8 V output matches original ThinkPad specifications
- Direct replacement for Lenovo X40 and X41 models
- New condition ensures full performance from first charge
- Black finish aligns with ThinkPad aesthetic
Compatible ThinkPad models
The Battery Technology Inc. IB-X40H is a replacement power pack built for Lenovo ThinkPad X40 and X41 notebooks. It uses an 8-cell lithium-ion design rated at 14.8 volts and 4400 mAh. The black casing matches the original aesthetic of these legacy machines.
Sustained runtime profile
Eight lithium-ion cells spread the discharge load, keeping voltage stable through a full work session rather than sagging after a short burst. The 4400 mAh capacity targets multi-hour operation on a single charge for typical office workloads. Internal cell balancing supports consistent cycle life over repeated daily use.
Upgrade context and limits
This unit replaces degraded or failed original batteries in X40 and X41 systems, restoring untethered mobility. It does not add capacity beyond the factory specification, so users needing longer unplugged time must carry a spare pack. Buyers with other ThinkPad models or newer series cannot use this battery.
Highlights
- 8-cell lithium-ion design delivers 4400 mAh capacity
- 8 V output matches original ThinkPad specifications
- Direct replacement for Lenovo X40 and X41 models
- New condition ensures full performance from first charge
- Black finish aligns with ThinkPad aesthetic
Specifications
| Brand | BTI |
|---|---|
| Model | IB-X40H |
| Type | Battery |
| Compatibility | Lenovo ThinkPad Notebook Series: X40, X41 |
| Battery Type | 8 Cell Lithium-Ion |
| Battery Voltage | 14.8V |
| Battery Capacity | 4400 mAh |
| Features | Color: Black |
| Shipping weight | 0.57 kg |
| Package size | 300 × 94 × 56 mm |
Questions about this item
Does the 8-cell 14.8V lithium-ion pack run hot or draw extra power during all-day use?
The 8-cell lithium-ion design operates at 14.8 volts and 4400 mAh, matching the original ThinkPad X40 and X41 thermal envelope without added heat or power draw.
What must my ThinkPad already have for this IB-X40H to fit and charge?
It fits directly into the battery bay of a ThinkPad X40 or X41; no extra caddy, adapter or proprietary connector is required.
Will the 4400 mAh capacity work reliably with the original X40 or X41 charging circuit?
Yes, the 4400 mAh 8-cell pack uses the same 14.8V lithium-ion chemistry the X40 and X41 charging circuits were designed for.
Also in this aisle
People compared these
Same shelf, same checkout — eight coins and a 30-minute rate lock.



