What are the lowest power consumption laptop like devices for light browsing? - Page 1
Forum section: electronics / general

author: electroniclearner820327
author_rank: Regular Contributor
timestamp: July 21, 2025, 09:24:26 am
content: This new/old, circa 2013, machine that was gifted to me works fine but it is such a power hog I don't think it is faesible to use it as it drains my modest 105ah leisure battery about 40-50% per day. Having just one cloudy day, meaning low solar, will put me into a heavy deficit and only just scraping by, day by day.A few days like that and I would have to be breaking into using the dc-dc charger, which was previously reserved only for deep winter.I can't imagine how bad it will be once the sun continues its march into the earth for autumn and winter.All this extra usage and with no benefit for my usage over the tiny tablet with keyboard I had which took much less power. That one was broken though, the charge port mucked up, which I didn't find out how to fix, hence the switch.So what uses the least power but has ok browsing capability?I know smartphones use a tiny amount but never used one and don't intend to start.I had originally thought of using a raspberry pi for this but will that be less power hungry? I am sure it depends a lot on which one right? I recall reading that version 4 takes up quite a bit but what about the others? On my previous research I remember that the zero, while it may take less power, would not handle browsing duty very well.Is that a good avenue to look into or are there better out of the box alternatives?Only want to spend a couple of hundred pound sterling at most, preferably under 100 but don't mind going over since I will be using it every day.

author: brucehoult
author_rank: Super Contributor
timestamp: July 21, 2025, 10:12:36 am
content: The Pi 4 does have quite a hungry CPU, but the problem with the Pi 3 or Pi Zero is the very limited RAM -- just 1 GB on a Pi 3 -- which is problematic for modern web browsing.There are a variety of A55 boards which came after the Pi 4 and are a little slower but use a lot less power: Odroid C2 and C4 and other boards using Amlogic S905-family chips. Or the Rockchip RK2566 and RK3568. The Allwinner A523.At some point the biggest power consumer is the screen, or more accurately the backlight for the screen.There are also a number of similar RISC-V SoCs and boards that are fairly low power but can take a decent amount of RAM. Several of these are even available in laptop computers, for example the MuseBook which has a SpacemiT K1 SoC and 36.48Wh/7.6V battery giving "up to 8+ hours" usage, which would put it at a power consumption of 4.5W, though apparently typical usage is more like 6 hours (i.e. 6W average).MuseBook was $299 with 8 GB RAM but is currently listed as out of stock.The DC-ROMA II uses the same SoC and lists for $399 but is also currently out of stock. However the original DC-ROMA with a JH7110 SoC seems to be available for $299 with 8 Gb RAM.https://store.deepcomputing.io/products/dc-roma-risc-v-laptopIt apparently only has a 3 hour battery life from a 48Wh battery as I think the JH7110 doesn't have a low power idle mode, although I don't understand this as my JH7110 VisionFive 2 SBC uses about 5W (no screen). IDK but I suspect 3hr must be wrong.The best is probably going to be a Chromebook or a tablet with a bluetooth keyboard (if desired).These are all going to be much slower than a 2013 x86 PC, more like a ~2000 PC, say one of the later Pentium III or PowerPC G4.

author: tunk
author_rank: Super Contributor
timestamp: July 21, 2025, 10:56:21 am
content: Wouldn't really know, but I think I would start by looking at low end chromebooks with an ARM processor.

author: electroniclearner820327
author_rank: Regular Contributor
timestamp: July 21, 2025, 04:14:32 pm
content: Quote from: brucehoult on July 21, 2025, 10:12:36 amThanks for the detailed information.Hmm, for the price, perhaps I might want to put my money elsewhere, like an additional lifepo4 battery instead? I could get quite a bit more solar for a couple of hundred quid but the limiting factor is the storage capacity as it tops out quite easily already with 300W of solar, so more would simply be a waste largely.Do you have any rough beermat guesses on power consumption of those smp pi like clones in terms of power consumption compared to my 2013 machine? As you say the backlight of the screen probably the lionshare of the power. Maybe it is simply that as the little notebook/tablet thingy I had before only had a 10" screen I believe but this one, I am not sure but looks like 2x the size at least, maybe more.

author: brucehoult
author_rank: Super Contributor
timestamp: July 21, 2025, 08:05:50 pm
content: Quote from: electroniclearner820327 on July 21, 2025, 04:14:32 pmYou haven't said how much power your 2013 machine uses and it could easily be anywhere in a 10:1 range.

author: Infraviolet
author_rank: Super Contributor
timestamp: July 21, 2025, 10:13:33 pm
content: One thing worth checking might be how efficient, or not, the "power brick"/"wall wart" which is charging the laptop is. If you're running plugged in all the time you might see about removing the battery from the laptop (the laptop's internal controller permanently trying to charge an older battery, one that never gets needed anyway if you stay attached to the wall, might well waste power) as most circa-2013 machines can run on just the DC power-brick supply. Maybe if the brick is old it has declined in efficiency over time, some laptops happily take any DC supply with the right size connector and the appropriate voltage and the correct current limit, so if the present power brick is inefficient maybe look for a new one of the same model or a generic very high efficiency one of the same voltage (ensure it describes itself as voltage regulated so you know it will keep that voltage when the load current rises or falls) and same current limit (find whatever adapter you'd need to go from the probably somewhat standard barrel jack of the DC supply to whatever more unusual input connector the laptop has).Another thing would be how many un-necessary background programs the laptop might be running which would waste power, a Linux OS probably does better here than a Windows one because Linux has a lot less going on in the background.I'm not sure if swapping from an HDD to SSD would make the machine more efficient, an SSD doesn't have to keep moving parts going, but an SSD can still get pretty warm so the power usage might not be that much less than an HDD.A general dusting out of the inside of the laptop might help make it cool itself a bit more effectively, so it wouldn't need to use as much power running the cooling fan(s).

author: radiolistener
author_rank: Super Contributor
timestamp: July 22, 2025, 12:48:36 am
content: I'm using a Raspberry Pi 4 with an old 19" 4:1 Samsung TFT display featuring a PVA matrix and CCFL backlighting.During a power outage, I power both from a 60 Ah PD power bank. Depending on the load, it consumes about 0.8-1.1 A @ 5 V from the USB port for the Raspberry Pi 4, and about 1.1 A @ 12 V from the DC port with reduced backlight (Text mode). With full backlight, the display consumes about 2 A @ 12 V.With reduced backlight, it can run for about 10-11 hours, with full backlight, about 6-7 hours.With a more modern and efficient display, it could run even longer. I can use full-featured Firefox or Chromium, watch videos, etc.Here is the link for powerbank:https://www.aliexpress.com/item/1005005891064789.htmlIt shows the selected voltage and current for every port and supports fast charging from a 100W PD charger within 2 hours, which is very useful.The only drawback is that it resets all ports when you connect or disconnect a new device, so if I power off the display or it goes to sleep due to inactivity, it causes the Raspberry Pi to reset because of the power interruption.For the router, I use a separate power bank, since the internet connection typically fails a few hours after a power outage due to the provider's backup batteries running flat. This requires shutting down the router, so to prevent power interruptions and resets on the Raspberry Pi, I power the router independently from its own power bank.For charging, I use a 100W charger from Ugreen. It’s not ideal, as under a 100W load the voltage drops from 20V to around 19V and the charger heats up noticeably (about 72°C after first hour). However it is compact and allows the power bank to recharge fairly quickly when mains power is available.I also have a 100W PD charging module from China, which allows me to recharge the power bank from a car battery that can be recharged via a solar panel.

author: SiliconWizard
author_rank: Super Contributor
timestamp: July 22, 2025, 01:13:26 am
content: If you're mentioning laptops and smartphones, you could consider the in-between: a tablet. Unless you're allergic to not having a keyboard and mouse/touchpad, which is understandable if your "browsing" involves a lot of typing (although you can usually pair a BT keyboard with the tablet). In terms of low consumption, size and weight, that should do it.With a recent OS (Android/iOS) and browser, unless you do very "light" browsing, I would recommend no less than 6 to 8GB of RAM. Otherwise, you're gonna suffer. Web browsers are increasingly RAM hungry. (Just for an idea, on my desktop, Firefox is currently using 6.1GB.) Now with older OS and browsers, less RAM could be ok (if you're after a second-hand device rather than new). I still occasionally use an oldish tablet with Android 8 (so that should tell you how old it is) and 3GB of RAM - mostly on the go or in lab/garage/ anywhere it could get damaged easily... or stolen. I basically don't care about it as it has essentially no value anymore, and that can be a great thing in some situations. But even on this oldish software, 3GB are sometimes limiting when browsing after a while.

author: radiolistener
author_rank: Super Contributor
timestamp: July 22, 2025, 01:17:22 am
content: I'm using Raspberry Pi 4 with 4GB and zram swap, Firefox with 5 tabs eats about 2 GB. But some sites may eat more.

author: Someone
author_rank: Super Contributor
timestamp: July 22, 2025, 01:22:01 am
content: Quote from: electroniclearner820327 on July 21, 2025, 09:24:26 amThis is a fairly niche requirement (absolute lowest energy consumption) but you can hunt through reviews from the bigger sites that cover a broad range of tech:https://www.anandtech.com/show/6476/acer-c7-chromebook-review/5You can take the minutes/hours duration against the same test but then normalise for the battery capacity.As above, a second hand device (as your budget will likely force) comes with the risk of a worn out battery that will self discharge (or faulty charge) and waste power. Best to budget for a new battery if you go second hand.Quote from: SiliconWizard on July 22, 2025, 01:13:26 amProbably depends on the specific sites and OS + hardware acceleration. I'm using some older iOS devices with 2GB and 3GB of ram and there is no problem with content consumption apps or websites. OS updates and software support is more a problem there. As for power consumption, absolutely under 5W as they will run on the 5V 1A charger and gain battery while in full use, browsing should be somewhere in the 2-3W range.

author: brucehoult
author_rank: Super Contributor
timestamp: July 22, 2025, 01:31:49 am
content: Quote from: radiolistener on July 22, 2025, 12:48:36 amI'm thinking of getting one of these. It's 30% more capacity (76800mAh @5V) for twice the price, but doesn't have the drawbacks you mention, plus it has solar panel MPPT controller (11-30V, 8A, 110W). And AC output.https://www.aliexpress.com/item/1005008686336203.htmlI have a much bigger 3kWh 3600W unit from Pecron, who also have a unit in this size range, but the small one isn't sold in NZ (yet?) while the Ecoflow is.

author: wilfred
author_rank: Super Contributor
timestamp: July 22, 2025, 01:59:31 am
content: I would go with a low end laptop because if you use a SBC like a Rpi you will still need a monitor. I've heard that an ad-blocker can make a meaningful reduction in power consumption on sites with multimedia ads. But the biggest savings come from having the machine go into a low power mode when inactive. Or switching it off when not in use. But you also need to watch the internet hardware modem and router.It depends on just what "light browsing" means. Is it occasional browsing or is it browsing but not cpu intensive browsing like youtube or is it low data bandwidth browsing. In the later case a mobile phone hotspot might be the lowest power option.A combination of a smartphone (get over it, I say) and a low power laptop might be worth considering. I don't like browsing on a small smartphone screen but for checking in in short bursts it has been very useful. I generally go to a computer to type.

author: radiolistener
author_rank: Super Contributor
timestamp: July 22, 2025, 02:41:49 am
content: In reality, power consumption doesn’t depend much on webpage content, though I do use uBlock Origin. The Raspberry Pi itself has a baseline consumption of around 0.5 A. Full CPU load on all four cores adds about 200-300 mA, and Ethernet uses around 150 mA. Since average CPU usage typically stays around 20-30%, overall consumption stays near 0.8 A. Additional power draw comes from USB devices - for example, a laser mouse with an optical sensor consumes about 120 mA, and an RTL-SDR dongle adds another 250 mA. The keyboard consumes almost no power - the difference is negligible, something like 20-40 mA. As result, the total consumption is about 1.0-1.1 A. With full CPU/GPU load (stress) it eats about 1.2-1.3 A.10" tablet eats the same about 1.5 A, which also include its display, but its slower and runs limited mobile browser with no way to install ublock origin.

author: DiTBho
author_rank: Super Contributor
timestamp: July 22, 2025, 03:23:58 am
content: A led backlighted 15" LCD is usually a 3 watt device

author: electroniclearner820327
author_rank: Regular Contributor
timestamp: July 22, 2025, 04:24:26 am
content: Quote from: brucehoult on July 21, 2025, 08:05:50 pmIndeed! That will also help compare against these other suggestions to see if it is actually low/high/medium on power consumption, which I have no reference for really at the moment.I checked it a couple of times with the power lead out, so using battery, and running a couple of different programs to check power usage for my normal browsing activities and they both read around the 20w range.So how does that compare to yours and other's suggestions? Helpful if others can reply with expected W consumption of their ideas to give something to measure against.Also why no love in replies for my suggestion of getting another leisure battery? I thought it is a good idea.More research to do on if another device will offer considerable power savings and if so what the price would be. Even the low end tablet with keyboard thing my mother gave me, which was about as cheap as they come, is listed on amazon at £279. Now that is not made for efficiency so I bet something that is would cost more.Hereis that other one I was using until it became unusable due to power port not working to take a charge.I am now using HP pavilion G6. The specshereseem right. This one has 750gb spinner hard drive and 7.5gb ram.I checked the two and the first one had 11.6" screen and this one apparently 15.6".So the important thing to find out is if I can expect any meaningful power saving with buying a different one but the 2nd leisure battery I am thinking is going to offer the best solution but still waiting for further replies to see if anything else is added to the pot of ideas.Another leisure battery of the same kind as my current 100Ah one would be £299 and that power I could also use for anything else if I wanted so seems if there aren't other devices that would be much cheaper and more efficient this is a good route to take.

author: electroniclearner820327
author_rank: Regular Contributor
timestamp: July 22, 2025, 04:28:19 am
content: Quote from: radiolistener on July 22, 2025, 02:41:49 amIn watts please? Isn't the calculation for watts 1.5 * 12 (V) so 18W? If so that is almost identical to the power consumption of this current laptop.

author: brucehoult
author_rank: Super Contributor
timestamp: July 22, 2025, 05:21:48 am
content: Quote from: electroniclearner820327 on July 22, 2025, 04:28:19 amNo, that's at 5V from USB.

author: electroniclearner820327
author_rank: Regular Contributor
timestamp: July 22, 2025, 07:09:46 am
content: Quote from: brucehoult on July 22, 2025, 05:21:48 amOh I see, so 7.5W vs. my machine's 20W average.So price and efficiency wise new PC vs new battery? Pi doesn't cost much but the screen I remember is nearly £100 for anything bigger than a matchbox and so maybe close to £200 with any other bits and pieces like case and such?Second hand for a tablet probably cheaper or even 2nd hand pi?