Dell D5318 Laptop Battery

[tmcw]

Have this D5318 battery that came with an Inspiron 9400, I've had it about a year, battery never worked in it, even with the right charger (90W or 130W), the battery charging indicator would blink a couple of time after plugging in the power connector, but it would go off. I wasn't really bothered about it, the laptop is really just used for playing media files, and does a nice job of it too, great speakers and screen.

Anyway, yesterday, the keyboard and trackpad started giving issues, the keyboard had delay or was forgetting keys had been pressed, and the trackpad made the pointer move jerky, so I was a bit disappointed. Plugging in a USB mouse and the pointer moved fine, so I was thinking some hardware issues. Then I noticed that the battery charging light was constantly flashing orange, so I took out the battery, and the keyboard and trackpad go back to operating normally. Why would this happen?

So I decided to crack open the battery pack, and can see one of the 6 cells is discoloured, leaked a bit, but still confined to itself, hasn't leaked to other cells or the circuit board. I've attached a photo of the cells.

What I'm wondering is if it's possible to take the obviously bad battery out of the circuit, and see if the others will charge, as like I said, the battery never worked for me, so I don't know if the laptop is capable of recharging battery packs, and don't want to splash out for a new battery if it's not gonna work. But if there was a way of knowing that it can (recharge), then I might (splash).

So, is there some modification I can do to the cells to at least test this? Would I have to go down to 3 cells? (I see the norm for batteries for this form factor are 6 and 9 cells. Would it work with 3, or 4?

Any tips from anyone who has had a bit of experience with testing/rebuilding laptop batteries?

[piernov]

Re: Dell D5318 Laptop Battery

First and foremost I must say that you should *not* play with lithium batteries. They are *very* dangerous. Even more so when you have a bad cell.

Now for the more technical part… The cell that looks bad is most likely internally shorted. The one in parallel is probably dead too. A battery pack that was designed to work with 6 cells cannot work with 3 or 4 cells as the BMS would need to be configured differently (either reprogrammed or some strapping on the circuit replaced) or replaced altogether to be able to work with different cell count.
For the battery pack to work at least the bad cell and the one in parallel would have to be replaced, hoping that the BMS didn't enter permanent failure mode. If it did, the fuse is blown and the BMS would have to be reset (requires an external programmer, some software and the key — which may be included in the software).

But again, don't play with that. It is dangerous. Get yourself a new battery pack, it's almost always the battery pack that's bad and almost never the charging circuit on the motherboard. Even when a "new" battery doesn't work, it's more often than not a bad battery as well.

[tmcw]

Re: Dell D5318 Laptop Battery

Thanks for the advice and information.

Yes, I'll leave well alone, and get a new battery. Hopefully the charging circuit is still ok.

I had messed with NiMH cells/batteries in the past, but Li-ion does seem to be more dangerous. So, not wanting to burn the place down, I'll let the recyclers deal with it.