m17 - R3 Battery problem

My m17-r3 is only one 20 months old and now the battery is acting up. Basically, the battery stops charging and switches over to ac at 70 percent. I have battery bar installed, which shows me 9.6 percent wear of 96,000 mwh. The problem is it also shows the capacity at 86,775 mwh but only charges to 61,290 mwh (70 percent of 96,000). I have fully discharged the battery to zero and then fully charging it hoping that would fix it but still the same. Bios is up to date as well. Am I really looking at a bad battery already!?

Thank you for the help

 

Sounds like a battery conservation option, so this would be perfectly normal behaviour. Check bios for the current charge setting.

For systems that are mostly tethered it is better for long-term battery health to charge them only up to their nominal voltage, about 3.7V. The 70% setting is a compromise; longer lifespan and a reasonable charge. Disadvantage is obviously that you have to remember to set it to 100% prior to taking it on the road.

 

Bios is set to standard charger and says the battery is in good health. Desktop charging mode has always been disabled.

 

You did find the 'limit charge' option in the bios then? And what is the current charge voltage in HWiNFO?

 

I can not find the "limit charge" option in the bios. When the laptop starts I push f2 to get into bios. I do not see this option. Thank you so much for your help. It is extremely appreciated.

 

Just reflashed the bios and still the same thing. No change. It says 1 hour 15 minutes until full then stops charging and says plugged in not charging.

 

Can you make a photo of the label on the battery? From a quick search the R3 packs are all 3S (3 cells in series), so 11.1V on the label (3x3.7V nominal) and ~12.6V when fully charged (3x4.2V full), but your system shows 15.7V even at a mere 70% charge. That'd suggest a 4-cell pack (14.8V) or a fake aftermarket item; 96Wh is a rather big claim.

 

this was a brand new machine when I purchased it. No one has been in it. Here are two pictures. Had to open the machine to get them. Bad idea on Dell. Here is another picture off the charger.

 

Ah, it's a 4-series then. In that case one of the four parallel sets is defective or can't be charged properly anymore. At 100% charge this pack should be at 16.8V, but since it's hanging at 15.7V that would indicate to the system there's only 70% left; 15.7/4 = 3.9V per cell, which is at 70% between 3.3V (empty) and 4.2V (fully charged). The voltage:capacity ratio is pretty much linear at this range.

Anyway, if there's still warranty left then an RMA is in order. If not then use a multimeter to verify the voltage of each set; if one of them shows 3.3V or less then remove it and check each cell individually and replace the faulty one. If all sets show 3.9V or so then the pack is fine and the problem is with the charger or the mb's charging circuit. The mb can be inspected visually for burned components; the mosfets of the charging circuit are quite large:

Spoiler: M18x R1 example

 

I am going to try to rma the battery with Dell - Alienware. If that fails, how would I test the battery for the bad cell. That would require opening the battery correct? There are many wires on the plug for the battery. Also, can I purchase a new cell? If so, what would be a quality brand cell?. Seems like I will be purchasing a new battery. Such a shame the quality of things today last just past the warranty period then fail. Thank you so much for the help.

 

Measure each for resistance, it should be close to zero.

The pack is molded plastic, so opening one would disqualify it for an rma. Unfortunately, it's not as simple as swapping one out in a normal battery holder. Needs a bit of soldering expertise and, preferably, a spot welder to attach the new cell. This is one of the best cells: Samsung INR18650-35E 3500mAh.

Electronics manufacturers have lobbied extensively in order to get warranty down from two years to just a single one. Those lawyers and their familiars were presumably cheaper than designing better products. Too bad you didn't happen to buy it in Europe; still two year minimum warranty, whatever the seller claims. Also, they're obligated to reimburse shipping costs.

 

Got no where with Dell. Purchased a new battery and it works perfectly. Thank you for the help. Going to replace the bad cell when I can find some time.