Inside a laptop battery - DELL D610

For DELL laptops it starts with a steady red battery light - indicating your laptop battery is finished. After 1-2 years of regular daily use it's not exceptional - Lithium Ion batteries don't last forever.  However a blinking red battery light indicates it simply needs charging.

There's one other variation on the flashing red battery light for DELL laptops; if it flashes 4 times red and 1 time green, battery power is so low it needs an immediate full charge cycle. This can be the case with new DELL Laptop batteries coming from stock. Usually the red/green flashing turns into a steady green light within 15-30 minutes after connecting the battery charger.
 

The C1295 53WH DELL Laptop battery casing

Laptop batteries are not particularly cheap and the industry has done many things to protect their position. So let's see what's inside the C1295 - 53WH Dell laptop battery with the aim for a possible DIY replacement.
 

C1295 DELL 53WH battery clip
How to open a DELL laptop battery

 
The DELL battery casing is a piece of art. It looks like the case is sealed forever. No way to open it without ruining the battery case - it seems. After a very close look it seems there is a small clip next to the connector. Raising the plastic a bit shows the key to opening the battery. The cover suddenly raises more and in one rip the whole cover comes off - just like that. Very easy removal, only if you know how.
 

Inside the DELL C1295 - 53WH battery

C1295 DELL 53WH casing open

Inside the DELL C1295 - 53WH are 6 lithium ion cells with a total capacity of 4.7Ah ( 4.7 continuous Amps during 1 hour max) at a voltage of 11.1 Volt. That's about 3.7 Volts per 8.3 WH lithium ion cell.

The battery has a charge controller inside, charging 3 groups of 2 batteries. A temperature sensor keeps an eye on overheating. Pretty nifty design inside, tightly fit in the battery casing. The batteries are spot welded together. Normal soldering would take too much space, the battery won't fit with soldering blobs on each end.

 

C1295 DELL 53WH battery pack

The Lithium Ion cells have markings: EJMF4-050557, EJMF4-046869, EIEF4-018780. It's some sort of production serial number and really not worth to Google. Trying to replace these batteries is a bit of a job. First to find identical cells, secondly to solder them together.

Looking at the 53WH / 4700mAh capacity and the internal wiring, one cell must have a minimum capacity of 2350mAh at 3.7 Volts.

 

DELL C1295 - 53WH DIY battery replacement

A quick market scan resulted in the discovery of a generic Lithium Ion cylindrical battery type the : Li-Ion 18650.

 

C1295 DELL 53WH charger

The components inside a DELL laptop battery - on the left the microcontroller board

An average capacity found in December 2008 is a 2600mAh Lithium Ion cell. The cost is about US$ 15 for a single cell, but prices are falling.

As an estimate six 2600 mAh (57WH) cells, lets' assume 45 US$ including soldering tabs (excluding shipment) to make the DYI a little easier.

The C1295 DELL battery now does about US$70 for 48WH. (excluding shipment). That's at least 25 US$ saved and a 9WH higher capacity in December 2008.

Looking a bit further reveals new Li-Ion 18650 battery capacities of 3000mAh. That's a 37 % capacity increase from the standard 48WH to 66 WH.

 
DELL AC Adapter not recognisedDELL ID chip diedDELL design failureInside a DELL battery
 

For those who want to know more about the pinout of the DELL battery connector, read more here.

IMPORTANT
:: Read the safety instructions when handling Lithium Ion batteries! These are high capacity batteries and can't take heat with the risk of explosion or early degradation.
 


 

This battery fits at least in the following DELL Laptop models

  • Dell Inspiron 500m, 600m,
  • Dell Latitude D500, D505, D600, D610
  • Dell Precision M20

 This DELL battery model is known by the following DELL partnumbers:

1X793, 1X793A00, 310-5195, 312-0068, 312-0084, 312-0090, 312-0191, 312-0309, 315-0084, 3R305, 4M983, 4P894, 6Y270, 7W999, 9X821, BAT1194, C1295, C2603, G2053, G2053 A01, U1544, W1605, 0R160,

 

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