Dell Precision M3800 Owner's Review

anyone using an external battery pack with the m3800?
I'm looking into buying one but they all have 4.5 max amps output.

 

What battery pack are you considering? You mean m3800?

Sent from my Nexus 5 using Tapatalk

 

yes the m3800. Corrected
I'm looking at these :

HyperJuice:
HyperJuice 1.5 External Battery for Apple MacBook, iPad, iPhone, USB Devices

Energizer:
http://www.amazon.com/Energizer-XP18000-Universal-External-Netbooks/dp/B002K8M9HC

 

I guess the m3800 only requires the 6.67 amps when charging the battery and probably working under full load. so a 4.5 amps external battery will do. maybe less.

 

Ok, so the official Dell AC adapter delivers 6.7 amps at 19.5 V DC.

The HyperJuice amperage is only 4.5 amps, which is basically the equivalent of a 90W AC adapter. That may still work with the M3800, though you will likely have reduced charge time, possible throttling, and almost certainly a warning when you boot about an unrecognized and/or underpowered AC adapter.

Meanwhile, the Energizer unit according to its product page only delivers 3.5 amps at DC 19V, which is roughly equivalent to a 65W adapter. I really wonder how they can claim that it's a "universal" power pack that works with "ANY" (emphasis theirs) laptop....

 

this guy experienced the throttling with the energizer xp1800 battery:

Dell M6700 much slower when connected to external battery pack (Energizer XP18000) - Super User

 

the hyperjuice has the biggest amp output I could find on the net. Maybe setting the internal battery charge level in the bios to low: something like stop charging the battery when it is 20% charged or charging the internal battery first then running off the external one won't cause throttling. but sill the hyperjuice seems the way to go.

 

I think the lowest value you can set for "Stop charging" is 80%. But even if it's lower, it won't be lower than the minimum start charging value, which is 50%. The only thing that might work would be if you charged the laptop off of the external pack while it was powered off and then used it on the internal battery -- but that seems like it would be difficult to plan. And even if you could do that, there's no guarantee that it wouldn't throttle anyway even if it weren't also trying to charge its internal battery off of that pack. I guess it depends on whether you're willing to risk losing some performance in exchange for having longer battery life, but if you're not, you're right that there doesn't appear to be a better product, so you'd be stuck.

 

plus the hyperjuice might overheat due to max current output draw :-(
just had a chat with the hyperjuice guys. they do free shipping but well I'll look around for a better solution and buy this if nothing else is available. I even thought of building a DIY kit like this guy: I made an external battery for my Air - MacRumors Forums

I even started ordering the parts but thought a ready made commercial solution involves less hassle. but I see there is nothing available. So I will probably do it the hard way. Those Lipo battery have a giant amp output.

 

Thanks for the heads up John.

I saw some eBay pages advertising the cost of import.. the seller I'm looking at doesnt have any details of import charges on the items page. How does import charges get added/charged to me - I've never bought from abroad before.. who would I pay and when would I be told what/if I have to pay import costs? Any idea.. - sounds like you've been down this avenue before; cheers.