Dell Battery Packs

[brethin]

I now have several Dell battery packs that fail to recharge because of the stupid EeProm chip saying they need to be replaced. I pop them open and check all the cells and find maybe 1 or 2 dead cells that will not hold a charge and the rest test fine.

I am looking for someone that rebuilds these. I do not have the hardware or software to reprogram them or I would do it myself.

What I would like to do is reuse the good batteries from these packs instead of buying all new batteries. If I could get say 2 working per 5 and pay a fee for the reprograming and cell swapping I think someone could make some $ and save alot of people some $.

[b700029]

Re: Dell Battery Packs

The hardware involved is rarely more than a few lengths of wire.

The software depends on the chip in question and can be easily found on the Internet.

[brethin]

Re: Dell Battery Packs

You make it sound so simple. So are you offering to do this?

[kc8adu]

Re: Dell Battery Packs

if you get a cell failure the bmc will lock out the pack till you rebuild.forget reusing so called "good" cells.at a certain number of cycles depending on the cells the risk of a dendrite increases.this short will not be stopped by the ptc.
get new,matched cells from a reputable brand.or toss it and save yourself a fire.

[ratdude747]

Re: Dell Battery Packs

if you get a cell failure the bmc will lock out the pack till you rebuild.forget reusing so called "good" cells.at a certain number of cycles depending on the cells the risk of a dendrite increases.this short will not be stopped by the ptc.
get new,matched cells from a reputable brand.or toss it and save yourself a fire.

yeah... and on the same note, some dell packs are a PITA to open if openable... the d400 battery comes to mind, as I hav yet to figure out how it is put together (not standard sonic welded clamshell)

[brethin]

Re: Dell Battery Packs

I have never had a cell leak, catch fire or explode from proper use. I do take care in recharging them, 18650's with no protection circuit (all used cells removed from Dell packs). As far a cycle count goes I ignore it, If the cell charges and holds a charge long enough to be useful then its still good and I use it where I can.

[Evil Lurker]

Re: Dell Battery Packs

www.batteryrefill.com

[japlytic]

Re: Dell Battery Packs

get new,matched cells from a reputable brand.

I always specify cells from the same brand and batch, which have been equally charged.
This is also important for UPS units.

[Toasty]

Re: Dell Battery Packs

www.batteryrefill.com

Sounds good until you see the price.

Just bought an OEM Dell for Latitude D800 series for $31 off Amazon.

Batteryrefill wants $79-$109 for the same with a -little- bit more capacity.

For $30 it doesn't make any money-sense to even start to tear one apart to replace cells.
At $4.50 each cell... Then you have to reset the chip.

[b700029]

Re: Dell Battery Packs

I always specify cells from the same brand and batch, which have been equally charged.
This is also important for UPS units.

Laptop batteries have balancing circuits built in so small capacity mismatches are ok, but since to avoid overdischarging it will only use as much as the smallest capacity cell, it makes sense they all have very close capacity.

[brethin]

Re: Dell Battery Packs

Totally agree with you Toasty. That is why I wanted to use/reuse cells that still charge/hold a charge. Figured if I had the packs to rebuild and tons of cells that are still good someone with the software could reprogram 1 pack for me and keep like 2 packs for themselfs for the trouble.

[severach]

Re: Dell Battery Packs

Just bought an OEM Dell for Latitude D800 series for $31 off Amazon.

Aged LiIon batteries are junk whether new or used. Honest sellers know this which is why all the 1 year old cell phone batteries get booted from retail establishments to eBay for pennies. New or used, none perform like the original battery once they turn one year old. eBay sellers don't provide date codes.

A pack rebuilt by a high volume seller will perform at least as well as the battery did when new.

[Toasty]

Re: Dell Battery Packs

There are no date codes on the replacement nor the original battery. Both match in every respect as far as labeling.

[brethin]

Re: Dell Battery Packs

While age may effect effect them and make them hold less of a charge than new I know for a fact just because they may be over a year old does not automatically make them junk. How they are stored and how they are used have a much greater effect on the lifetime of the battery than just age.

[Evil Lurker]

Re: Dell Battery Packs

Aged LiIon batteries are junk whether new or used. Honest sellers know this which is why all the 1 year old cell phone batteries get booted from retail establishments to eBay for pennies. New or used, none perform like the original battery once they turn one year old. eBay sellers don't provide date codes.

A pack rebuilt by a high volume seller will perform at least as well as the battery did when new.

That is why I recommended them as a possible candidate as a supplier for rebuilt batteries. Supposedly they keep a fresh supply of batteries coming in all the time so you don't end up buying a battery that has set on the shelf for god knows how long. Plus I imagine they have the proper equipment to weld the batteries together, reset the eeproms, and most importantly the expertise to open the battery packs without destroying them.

[brethin]

Re: Dell Battery Packs

After several hours of testing the 4,8,12 cell packs I find when the pack claims to be dead, will not charge and flashes lights etc. It is because 1 or more of the group of 4 cells are discharged too low and the pack claims the entire battery is dead.
Without software I have been able to open packs that use 4,8,12 cells and check each group (there are at least 4 cells or 8 or 12) and I find most of the time 1 group is dead while the others are good so I slow charge any bad group above 2.5v and then place it back in the laptop and it starts charging again with no flashing lights to replace the pack.
More testing to come because to me Dell might make a fair laptop but knows jack shit about battery management.

[brethin]

Re: Dell Battery Packs

This does not reset any of the stats for the pack (wear lvl, full charge etc) it only allows a pack to charge again that would not charge due to the dead pack flag because 1 or more groups of cells in the pack were too dead and makes the entire pack flag as dead and not charge.

[brethin]

Re: Dell Battery Packs

All of my testing has been with Dell packs that use 4,8,12 cells. If your dell uses 3,6,9 whatever then I would ignore what I am doing untill I get a setup for those packs, if your not sure just pop it open and look.

[ibooster]

Re: Dell Battery Packs

On a tangent note, any recommendation for a laptop that is dell or HP in market that hold battery. i am not finding any laptop to hold as much battery life like they advertise. I need something with a solid 3 hour battery life with multiple firefox windows open, that is all I am not a gamer or high power user, just a normal user !