Dell laptop battery and general battery confusion

[Wicked_Sludge]

maybe its the lack of sleep, or maybe dell is lying....but heres my deal:

old dell inspiron notebook. original battery died after so many years. took it apart to find they used 8 slightly-larger-than-AA-cell batteries to make the pack. thats fine, the computer is plugged in most of the time, so i replaced them with 8 AA Ni-MH cells from wally world...thinking the new lower capacity batteries should still out-perform the old but higher capacity originals, which they did. but things have changed and i need my capacity back.

the side of the original cells are printed with an amazing 4.5 AH rating (or 4500 MAH, or 5.4 watt-hours)...X8 means the original capacity was 43 watt-hours, which is confirmed by what dell sells on their site. my problem is i cant find any cells even CLOSE to that capacity. hardly anything is over 3000 MAH even in D size (which wouldnt fit anyway). i was even looking at lithium ion batteries which should have a way higher energy density than the Ni-HM originals but those are all rated right around 2500-3000 MAH too...about the same as most AA-size Ni-HMs.

so my question is this: where the heck did dell get these amazingly high capacity Ni-HM batteries? what size are these things? they are slightly larger in diameter and about an inch longer than a standard AA. even more confusing, they offer an even higher capacity (65 watt-hours, still with 8 cells) optional battery. im confused!

 

[4x4fun]

rc hobby store

 

[Wicked_Sludge]

most 7 and 6 cell packs dont even have the capacity of one of these cells from dell. i can find individual cells that come close (4300MAH), but they are "C" cells which wont fit.

i found the original cells that dell used. they are made by sanyo, who claims they are some kind of high-tech "twicell" Ni-HM hybrid thing. the claim higher energy density than Lithium-ion. these are some space-age ultra high density gizmos for sure. i had half-hoped that i could find a replacement with an even higher capacity, but i dont think thats going to happen. seems dell did a damn good job picking their cells.

 

[Bob Ayers]

They are Lithium-Ion, Not NiMH.

You are better off replacing the entire battery, it has some charging electronics, and if there is a problem with it, you can have a fire hazard
on your hands.

 

[Wicked_Sludge]

http://www.sanyo.co.jp/energy/english/product/twicell_2.html

they are Ni-HM

they are the HR-4/3FAU cells at the bottom of the first list.

the charging electronics are functioning fine. the battery pack is wired in series and has simple (+) and (-) connections to the charging electronics with a thermal sensor that needs to be placed on the batteries. ive been searching for sanyo dealers and so far have found cells for $6.90 each with soldering tabs. so i can replace the cells for about $55 vs $130 for a whole pack from dell. i think ill go this route. im considering modifying the computer so the charging electronics stay inside the laptop. then i can build two battery packs with my own plugs to easily switch them out when one goes low. twice the capacity and still under the cost of a single pack from dell

 

[Bob Ayers]

http://www.sanyo.co.jp/energy/english/product/twicell_2.html

they are Ni-HM

they are the HR-4/3FAU cells at the bottom of the first list.

the charging electronics are functioning fine. the battery pack is wired in series and has simple (+) and (-) connections to the charging electronics with a thermal sensor that needs to be placed on the batteries. ive been searching for sanyo dealers and so far have found cells for $6.90 each with soldering tabs. so i can replace the cells for about $55 vs $130 for a whole pack from dell. i think ill go this route. im considering modifying the computer so the charging electronics stay inside the laptop. then i can build two battery packs with my own plugs to easily switch them out when one goes low. twice the capacity and still under the cost of a single pack from dell

The charging electronics for Lithium-Ion is complex. The charge starts out charging with a constant current, then switches to constant voltage. So I doubt that you have checked it out properly! Also built into the battery electronics is a FLASH memory for storing the charging parameters history. So,
stay with the charging electronics in one battery!!

 

[Wicked_Sludge]

http://www.sanyo.co.jp/energy/english/product/twicell_2.html

they are Ni-HM

they are the HR-4/3FAU cells at the bottom of the first list.

the cells arent lithium-ion. they are nickel metal hydride. since im going to be replacing them with nickel metal hydride cells (the exact same cells that were in the pack originally), the charging system will work just as it should.

 

[Bob Ayers]

the cells arent lithium-ion. they are nickel metal hydride. since im going to be replacing them with nickel metal hydride cells (the exact same cells that were in the pack originally), the charging system will work just as it should.

I have never seen an Dell Inspiron that took anything other than a Lithium-Ion battery, what model is it?

 

[Wicked_Sludge]

1200.

the batteries have the part number printed on them. they are the HR-4/3FAU's i posted. they come in the 43 watt-hour battery. the 63 watt-hour uses litium ions.

 

[Bob Ayers]

1200.

the batteries have the part number printed on them. they are the HR-4/3FAU's i posted. they come in the 43 watt-hour battery. the 63 watt-hour uses litium ions.

It takes a Lithium Ion!!!!

http://accessories.us.dell.com/sna/category.aspx?c=us&l=en&s=dhs&cs=19&category_id=2999&mfgpid=167566&chassisid=-1

 

[Wicked_Sludge]

yep, theres the 65 watt-hour lithium ion upgrade. and HERE (<---click) is the 43 watt-hour Ni-HM battery i have.

strangly, 1.2 volts per cell...not 3.6 like lithium-ion.

sanyo part number corresponding to the part number for the Ni-HM cell on sanyos website.

im REALLY anxious to hear you admit your wrong bob

 

[Mark_88]

Ah, I see the problem...they are stamped with JAH...which is Rastafarian for God...so...they are only made by Angels who smoke the 'erb...

 

[LearjetMinako]

I'm surprized that the laptop only takes 8x NiMH cells. Most that I've seen need a voltage of 13V or higher. And 4500mah in an AA cell is really remarkable. I do the R/C stuff, and the highest I've seen for AA cells is 3200mah. Sub-C is about 4600~5100, Li-Po/Ion vary with size but are around 5000mah for the same size of 6x sub-C batteries @ 7.2~7.4V.

 

[Wicked_Sludge]

4500mah in an AA cell is really remarkable.

i found out they are size "A". 18 MM in diameter and 67 MM long vs an AA's 14.2X50MM. so they are a little bigger...but still an amazingly high amount of storage for such a small battery.

i was surprised to see only 8 cells in there too. the voltage of the pack makes it hard for me to come up with a high-capacity alternative (i was thinking about maybe making a less-portable, external, extremely high capacity battery to go along with my 2 custom swappable packs...you know, for those 48 hour power-outs, camping, and what-have-you were weight and portability arent concerns). i thought about just hooking it to an 8V lawn and garden deep cycle...but i dont know if the computer will fire up on the ragged edge of low-voltage.

 

[rboyer]

Just get a jump box and a car charger. That's what I do.