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Finding Replacement Battery Pack

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jjdrp

New Member
I am trying to find a replacement battery pack for my portable/wearable computer. It is an internal battery that keeps the CPU running if I need to move the computer or switch the power source.

My issue is that I am a bit confused about the specs of the current battery pack.

Below is the label on the battery. It states that it is 8.4V, but it has 14 cells. I thought that each cell was 1.2V. So how did they arrive at 8.4V or should it be 16.8V?
7903-battery.jpg




I also opened up the pack to see if there was more details and here is a photo:
7904-battery2.jpg



My goal is to use a replacement pack with similar specs. Maybe something for a RC car.

If it helps any, the output of the power brick is 12V, 4A.


  1. So is it 8.4V or 16.8V?
  2. I read that a higher mAh rating is always better. Am I correct?

Thank you.
 

crutschow

Well-Known Member
Most Helpful Member
1. It appears to be an 8.4V battery. Perhaps it has two cells connected in parallel (can you see the battery connections?), although that's not recommended practice.

2. A higher mAh is better. It will give you a longer running time.
 

jjdrp

New Member
I followed the connections and you are correct. I guess they did this to improve the capacity...

Thank you
 

Sceadwian

Banned
Stupid, they should have just used AA batteries. It wastes more space and weight on the extra casing required for the AAA's than it gains capacity by putting them in parallel. Even smarter they should have used a lithium pack.

A higher MA rating is may not always better. If I'm not mistaken high capacity NiMH cells have fewer charge/discharge cycles than 'normal' capacity NiMH's do.
 

Willbe

New Member
Try Hosfelt, allelectronics, Mouser, digi-key, Allied, Jameco.
 

Dean Huster

Well-Known Member
NiMH may have been the current battery trend when this thing was manufactured. Remember that NiMH had started replacing NiCd technology and the lithium chemistries were still problematic with cost, explosions, improper charging, improper discharging, etc. for several years after NiMH was developed before it finally became feasible and cost-effective. Although the AA package would have provided the higher power needed, it may have been much too thick for the application. Remember that designers like to build around required features and not available battery sizes. That's why you often get ******* battery sizes in your digital cameras and such.

Dean
 

jjdrp

New Member
Dean you are correct.
As a wearable it is so compact that there was no way of fitting AA batteries. Also the batteries were not meant to power the device, but to act as a temporary power source. There is also an external LI pack meant for actual use. The computer was made in 2001.

Anyhow my intention is to stash this in my car instead of wearing it on my belt so I have more flexibility. Most likely I go with another size and secure it on the outside of the device. I only need the battery to enable automatic hibernation after the ignition is turned off.


Thanks as well Willbe.
 
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