HP EliteBook 840 G5 / 840 G6 / 830 G5 50Wh 3-Cell Battery (CS03XL) — quick answer
The HP EliteBook 840 G5 / 840 G6 / 830 G5 50Wh 3-Cell Battery (CS03XL) is a genuine, tested HP replacement battery available at N.N Laptops, Hafeez Center, Lahore for Rs. 12,699. It's a 50Wh 3-cell internal pack rated at 11.55V and fits EliteBook 840 G5, EliteBook 840 G6, EliteBook 830 G5. Comes with our 30-day check warranty plus Lahore delivery and nationwide.
Full specifications
| Brand | HP |
|---|---|
| Capacity | 50Wh |
| Voltage | 11.55V |
| Cell Configuration | 3-cell internal |
| Chemistry | Li-Polymer / Li-Ion (matched to OEM spec) |
| Compatible Models | EliteBook 840 G5, EliteBook 840 G6, EliteBook 830 G5, EliteBook 830 G6, EliteBook 850 G5, EliteBook 850 G6 |
| Cycle Life (Rated) | 400-600 full cycles |
| Condition | Genuine — Tested |
| Warranty | 30-day check warranty |
Compatibility — which laptops does this battery fit?
This 50Wh 3-cell internal battery is a direct OEM replacement for the following HP laptops:
- EliteBook 840 G5
- EliteBook 840 G6
- EliteBook 830 G5
- EliteBook 830 G6
- EliteBook 850 G5
- EliteBook 850 G6
Match the OEM part number on the sticker of your current battery before ordering. If your old battery part number isn't on this list but the laptop is, message us — there are often three or four interchangeable part numbers per chassis.
Battery health — what we test before shipping
Every battery on our shelf goes through a 5-point test before listing:
- Capacity — we measure actual usable Wh and only ship packs at 95%+ of rated capacity.
- Cycle count — read from the embedded BMS chip; we don't sell anything over 100 cycles.
- Cell balance — all 3-cell internal cells within 50mV of each other.
- Charge/discharge cycle — verified full cycle without thermal anomaly.
- Visual — no swelling, no bulging, no scorched contacts.
Installation — how to swap the battery
Internal 3-cell batteries on modern HP laptops require opening the back panel (8-12 Phillips screws, sometimes Torx T5). Disconnect the AC adapter, unscrew the panel, locate the battery connector on the board, gently lift the ribbon connector latch, unscrew the battery hold-down screws, lift out the old pack, and reverse the steps with the new one. Total time: 10-15 minutes.
Free installation in shop
If you're in Lahore, bring the laptop to Hafeez Center — installation is free with battery purchase. We'll also calibrate the new pack (full charge → full discharge → full charge) so Windows / macOS reads the correct capacity from day one.
Real-world battery life — what to expect
With this 50Wh pack and balanced Windows / macOS settings (70% brightness, Wi-Fi on, mixed use), expect:
- Web + Office work: 5-7 hours
- Video playback: 6-8 hours
- Code compilation / Photoshop: 2-3 hours
- Gaming or heavy GPU load: 60-90 minutes
These figures match Apple / Dell / HP / Lenovo published specs for the listed models. If your old battery was giving you 2 hours, the new one will restore the original full runtime.
Where to buy in Lahore — and warranty terms
Visit us at Shop 66A, 3rd Floor, Hafeez Center, Gulberg III, Lahore. We test the new pack on your laptop before you buy — if Windows / macOS reads the correct cycle count and design capacity, you walk out happy. Lahore deliveries are free; nationwide via TCS / Leopards covers Karachi, Islamabad, Faisalabad, Multan and Peshawar in 1-3 working days. WhatsApp 0314 4000131 to confirm stock.
Browse all our laptop batteries, laptop chargers, complete laptop parts catalogue.
Warranty — what you're protected against
Every battery carries our 30-day check warranty. If the pack fails to charge, shows wrong capacity in Windows / macOS, drops below 85% of rated Wh in our diagnostic, or develops any swelling within 30 days, bring it back to the shop with the invoice for full replacement or refund. No questions asked within the warranty window.
Frequently asked questions
Do I need to take the laptop apart to install the 3-cell battery?
Internal batteries need the back panel removed — typically 8-12 Phillips screws, then disconnect the old battery cable, swap, and reseat. We do free in-shop installation in Lahore if you bring the laptop. Removable 6-cell / 9-cell batteries on older laptops just slide in/out with a latch — no tools needed.
How much battery backup will I get on my EliteBook 840 G5?
With this 50Wh pack at default Windows balanced settings, expect 5-7 hours of mixed-use battery life (web, Office, video). Brightness at 70%, Wi-Fi on, no heavy GPU workload. Gaming or compiling drains in 90-120 minutes — that's normal for any laptop battery this size.
Is this a genuine OEM battery or aftermarket?
Our stock comes in both genuine HP pulls (tested cells, original casing, often the higher price) and high-grade A-class compatible cells (tested for capacity at 95%+ of rated Wh). Tell us which you want on WhatsApp 0314 4000131 — both carry the same 30-day check warranty.
How long will the new battery last?
A fresh quality cell-pack should give you 400-600 full charge cycles (about 2-3 years of daily use) before noticeable capacity drop. Avoid leaving the laptop plugged in at 100% all day — keep it cycling between 40% and 85% for longest cell life.
N.N Laptops — Shop 66A, 3rd Floor, Hafeez Center, Gulberg III, Lahore. WhatsApp / Call 0314 4000131. Lahore delivery, with nationwide delivery via TCS / Leopards, 30-day check warranty.
Bench-Tested and Verified for Peak Performance
Before listing, every battery goes through our bench-testing rig. We simulate a full charge-discharge cycle using a professional load tester to confirm the actual capacity matches the rated 50Wh. Only packs that pass with 95%+ capacity and no voltage drops make it to the shelf. This is the same rigorous check we do for all batteries at nnlaptops.com — whether you're in Lahore, Karachi, Islamabad, or Rawalpindi, you get a pack that's been verified by hand.
Why the 50Wh 3-Cell Pack Is a Smart Choice
Compared to the heavier 6-cell 65Wh battery, this 3-cell internal pack keeps your EliteBook lighter and more portable — ideal for commuters who carry their laptop daily. The 50Wh capacity gives you a solid 5-7 hours of real-world use, which is plenty for a workday in the office or a long flight. If you rarely run intensive tasks, this pack offers the best balance of weight and runtime. For users in Faisalabad, Multan, or Sialkot who need longer endurance, we also carry the 6-cell option — ask Sayam on WhatsApp 0314 4000131 for advice.
Extend Your Battery's Lifespan with These Tips
- Keep your laptop between 40% and 85% charge when plugged in for long periods — full cycles wear cells faster.
- Use HP Power Assistant or Windows battery saver mode to limit charge to 80% if you're always on AC.
- Avoid extreme heat: don't leave the laptop in a car in Lahore summer — heat degrades Li-Polymer cells quickly.
- Calibrate once a month: fully charge, fully discharge to 5%, then charge back to 100% to keep the BMS accurate.
Our 30-day check warranty covers any defects, but following these steps will help you get the full 400-600 cycles. If you have questions about your specific usage, contact Sayam on WhatsApp 0314 4000131 — he can recommend the right battery from our nnlaptops.com stock.
