Latitude 7450 Owners' Thread

It's in the BIOS.

 

I have had no frustrations at all with mine. My 1080p matte screen is plenty bright. I am now sitting in a bright airport on a sunny day with lots of windows and this is the first time I have put the screen up to 100% brightness.

I have been a lifelong Thinkpad customer, but Lenovo's Superfish debacle (I know that Thinkpads were unaffected) and their inability to make available a discrete graphics T450s with a docking port (both important to me) led me to the Dell 7450. The Dell's ability to have 16 GB RAM vs. the T450s' 12 GB limit sealed the deal.

So, from the perspective of a Thinkpad guy, the 7450 has been very impressive. The Thinkpad probably still has a superior keyboard and trackpoint (at least compared to my last one, a Thinkpad W520), but the 7450 is not very far behind at all and I have had exactly zero issues with the input devices on the Dell. I also like that Dell kept the separate buttons for the touchpad vs the clickpad on the newer Thinkpads.

Downsides of the Dell for me is the fact that the battery solution doesn't allow for larger battery options like the Thinkpads have. I would love for my 7450 to have an option for a 6/9 cell like the T or X series Thinkpads. I would consider a slice battery for trips, but it looks like the 7450 doesn't have that option unlike older Latitudes. I have purchased the Dell Power Companion (18000 mAh) and will be evaluating it over my next few business trips, but I would prefer an integrated solution.

 

Alternatively, you could buy a spare standard battery (which is what I've done for my E7440). Unlike many recent thin notebooks the battery is easily swappable and, because it is quite thin, is easy to stow into a laptop bag. We have just established that the E7450 battery is compatible with the E7440 so I would expect the converse to also be true and the prices of the E7440 batteries are now quite reasonable.

John

 

I am thinking which would be the better, spare battery or the 18Ah power companion. The companion is a bit heavier (400 vs 300g) but seems sturdier and higher capacity -in theory it should hold definitely longer than the internal battery.

Thanks!

 

The external battery appears to connect through the power socket so the internal voltage in the battery pack has to be transformed up to 19.5V so there will be conversion losses unless Dell have been very clever and use the centre pin the power connector to detect the power companion and accept a lower voltage.

I'm also puzzled what power conpanion's actual power capacity since this is measured in Watt-hours. 18Ah x 7.4V = 133.2 Whr which looks too much for the size of battery. 18Ah x 3.7V (ie single Lithium cell voltage) = 66.6 Whr which is more plausible considering the weight. That's more than the internal battery.

John

 

Corrected myself, you must be right, John, 133Wh seems extreme for the 6 cells of the companion, best case its around 1.5x more than the 4cell internal battery. However, the question is, how much do we loose on the voltage conversion... A bigger (aftermarket?) internal battery would be more economical.

 

I would also love to know the overall conversion efficiency. This article gives a range of 75% to 98% for a DC to DC switched mode converter. I suspect it depends on cost but would hope that it is better than 90%. The test is how hot the external battery gets when being discharged - the conversion loss is turned into heat.

John

 

The loss should be on the worse side of the range, this review on the XPS13 (52Wh internal battery) showed only 50% added battery life with the 12Ah model. Extrapolating this to our situation, the bigger companion wouldn't even be equivalent to one internal battery. There is another external battery option, the 97Wh slice (at least here we see a standard capacity indication...) but I am afraid, that would also suffer the conversion/efficiency problems and the added battery life/weight winner remains the spare internal battery.

 

The slice should have minimal conversion loss as I expect it is directly connected to the notebook's power circuit through the docking port. The slice looks to be roughly twice the size and weight (although I can't find a specified weight) of an internal battery but has about double the capacity. It all depends on the extra battery run time you need. I had a spare battery in my bag on a recent trip but never used it because the E7440 was quite frugal under light usage (but didn't notice the extra weight in the bag).

If you have already purchased the Power companion then you will be able to tell us how it performs. Otherwise, the best value solution is to get the E7440 45/47Whr battery since these are easy to find.

John

 

I canceled the idea of the companion, I don't want to buy anything lesser than the internal battery - especially if it weighs more. The slice might be interesting, but I cannot find any detailed tests on battery life (of any notebooks) with and without it.