Power Packs

[Daryk]

As has been discussed elsewhere on the board, there's a small problem with power packs.  Micro Power Packs have significantly higher power density than any other size, and the rules in AToW explicitly state any size pack can be used with any device unless there's a specific prohibition in the equipment description (page 307 refers).  Also, this power density is completely out of line with all the other packs of the same kind.  To fix this, I propose using the table below instead of the power packs listed in AToW.  Below the table, I present a rule to vary the output of a Kinetic Recharger based on a character's attributes (since the Kinetic Recharger featured so heavily in the calculations that underpin the table).  My thanks to Cray for helping me noodle through this.

The bottom line effects of this proposal are to Nerf Micro Power Packs and increase the capacity of just about every other size, but bring them all into alignment with consistent power density for each type.

Note: The "Battle Armor Power Packs" were an attempt to bring them into some kind of alignment with the rest.  I went with "Quick Charge" for them because the BA fluff talks about integral rechargers as part of the BA power system, and "Quick Charge" packs get 2 Power Points for every 1 put into them (resulting in the longest possible life).  Feel free to ignore them in the table if you don't want to cross BA scale and personal scale equipment like that.

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Item Ratings Cost Mass (g) Capacity(PP) Charging Rate Notes
Standard Power Packs 7.5 g/PP
Micro Power Pack C/A-B-A/A 10 15 2 Normal
Power Pack C/A-B-A/A 5 300 40 Normal
Satchel Battery D/A-B-A/A 20 3,000 400 Normal
Military Power Pack D/A-B-A/B 40 6,000 800 Normal
Support Weapon Power Pack D/B-D-C/C 750 22,500 3,000 Normal Encumbering; Can power 1 Support Weapon or up to 6 smaller devices

High Capacity (HC) Power Packs 5 g/PP
Micro Power Pack E/B-C-C/A 30 20 4 Slow Charge
Power Pack D/A-C-B/A 15 300 60 Slow Charge
Satchel Battery D/B-C-B/A 60 3,000 600 Slow Charge
Military Power Pack D/C-C-B/B 120 6,000 1,200 Slow Charge
Support Weapon Power Pack D/C-D-C/C 2,250 25,000 5,000 Slow Charge Encumbering; Can power 1 Support Weapon or up to 6 smaller devices

Quick Charge (QC) Power Packs 10 g/PP
Micro Power Pack D/B-C-C/A 20 20 2 Quick Charge
Power Pack D/B-C-B/A 10 300 30 Quick Charge
Satchel Battery D/C-C-B/A 40 3,000 300 Quick Charge
Military Power Pack D/A-C-B/B 80 6,000 600 Quick Charge
Support Weapon Power Pack D/B-C-B/C 1,500 25,000 2,500 Quick Charge Encumbering; Can power 1 Support Weapon or up to 6 smaller devices
Battle Armor Power Pack D/B-C-B/C 1,000 25,000 2,500 Quick Charge Encumbering

Civilian Power Packs 10 g/PP
Micro Power Pack C/A-B-A/A 5 20 2 Slow Charge
Power Pack C/A-B-A/A 2 250 25 Slow Charge
Portable Power Unit C/A-C-B/A 10 2,000 200 Slow Charge
Backpack Power Pack C/A-C-B/A 20 4,000 400 Slow Charge
Heavy Power Pack C/A-C-B/A 200 25,000 2,500 Slow Charge Encumbering; Can power 1 Support Weapon or up to 6 smaller devices

Clan Power Packs 4 g/PP
Micro Power Pack F/X-E-C/A 50 20 5 Quick Charge
Power Pack F/X-D-B/A 25 280 70 Quick Charge
Satchel Battery F/X-E-C/A 100 2,500 625 Quick Charge
Military Power Pack F/X-E-C/B 200 5,000 1,250 Quick Charge
Support Weapon Power Pack F/X-E-C/C 3,750 20,000 5,000 Quick Charge Encumbering; Can power 1 Support Weapon or up to 6 smaller devices
Battle Armor Power Pack F/X-E-C/C 5,000 25,000 6,250 Quick Charge Encumbering
As an optional rule, instead of a flat 5 Power Points per hour, Kinetic Rechargers instead produce 1 Power Point per hour per point of a character's Strength.  Characters operating a Kinetic Recharger suffer one point of Fatigue Damage for every Body+Will minutes they crank.  Characters with the Fit trait double this time, but do not halve and round the damage as normal.  Characters with the Toughness trait multiply the time by 1.5, and also don't halve the damage.  Characters with both traits triple the time, and still don't halve the damage.  A character can crank less vigorously and extend the time between taking Fatigue Damage proportionally.  For example, a character with a 4 STR, BOD and WIL could crank at a rate of 2 PP/hour (half normal) and only suffer one point of Fatigue Damage every 16 minutes (twice the normal time).  The minimum Fatigue Damage for cranking on a Kinetic Recharger for an hour is 1 point.

The current Fatigue recovery rules allow a character to recover all of their Fatigue in two 5-second turns.  This is clearly incompatible with the above optional rule.  While this could be attributed to a surge of adrenalin, having actually run for an hour without stopping, I recommend at least 5 minutes per Power Point generated to recover Fatigue from continuous strenuous activity like cranking on a Kinetic Recharger.

[Nebfer]

Well from a weapons stand point, it dose help a bit with energy weapons, when compared to ballistic weapons.

Canonically Energy weapons have very heavy ammo requirements, particularly if one wanted to use automatic energy weapons. For example the Military Power Pack, which IIRC if fluffed as a back pack power cell is 6kg (13 pounds), but only provides 60 shots, which is enough for four fully automatic bursts. The Generic Auto Rifle can have the same amount of shots for just a kilogram.

Your fix dose allow for 160 shots (10 full bursts and some left over), which is a lot more adequate amount of shots for a combat mission than 60 (unless your armed with say a bolt action).

Though to me it seems that you may have nerfed the Micro a bit to much, notably when you look at items that logically use them, notably small coms units, helmets and what nought, now you either have to use the 300g units, or your going to have to swap out the batteries every hour or two (vs the better part of a day).

Personally I views that most items only had one or two ports for power packs, IIRC a few laser weapons mention them having two ports that allowed batteries. This to me balanced the micros a bit, as they only had 3 or 4 shots when used by Micros. So that you could only use or two packs at a time.

Personally I would have pit that the Micro having a base of 5 PP.

I do like the inclusion of Civilian equipment, in some of my mods I added a Civilian line, I also tend to add a 67 era equipment (I tend to view that the items we see currently are largely 3040-3065 era equipment).

[Daryk]

Thanks for the feedback!  If I had pegged the micro power packs to 5 PP, that would have really cranked up the other sizes, as the main thing I was shooting for was consistency of power density.  As light as micro packs are, I didn't see having to swap them out a few more times per day as that great a 'Nerf'.

[bluedragon7]

Other fix: reduce the power consumption of those items that only fit micro power packs.
I think that is the actual source of the problem: for very small items the power consumption is too high so the micro power packs used to power them have a too high capacity to make those items useable.

[Daryk]

Very good point!  I don't recommend trying estimate what a "Power Point" works out to in actual units because the energy weapon requirements drive it WAY up.

[Terrace]

*Discussion about stuff using Micro Power Packs*

*Looks at my phone, which can't go for more than 2-3 hours of continuous use on a single charge, even when I'm just using it to browse the internet.*

I find this to be highly realistic. Maybe have the power draw for items that use Micro Power Packs only be the max rate, with all the features in active use at the same time? For example, the helmet for the ComStar Infantry Kit contains not only a Military Communicator, Infrared Scanner, and Night Vision, but a Rangefinder and Ultrasonic Detector for 3 PPH. But you're not seriously gonna use all those features at the same time, right?

[Daryk]

Another good point, but I'll add that Rangefinders and Ultra Sonic Detectors don't need power continuously, so bluedragon7's point still mostly stands.  The other bits of tech you mentioned could be argued to draw continuous power, but fall into that "don't look too close" category.  Seriously, energy weapons need a LOT of power...

[Retry]

*Discussion about stuff using Micro Power Packs*

*Looks at my phone, which can't go for more than 2-3 hours of continuous use on a single charge, even when I'm just using it to browse the internet.*

I find this to be highly realistic.

If Humanity somehow makes it 1000 more years and we don't figure out how to build a better battery, I'm going to be immensely disappointed.

If we're still rolling with liquid-state lithium-ion batteries in the year of our lord 3000 my skeleton or ghost or whatever's left shall rise up and declare the Human Race as failed, and I don't care if we terraform Mars, build a space elevator to the moon, and start up a Dyson Swarm all in the same week.

[VhenRa]

Another good point, but I'll add that Rangefinders and Ultra Sonic Detectors don't need power continuously, so bluedragon7's point still mostly stands.  The other bits of tech you mentioned could be argued to draw continuous power, but fall into that "don't look too close" category.  Seriously, energy weapons need a LOT of power...

I'll point out... Rangefinder is also night-vision gear.

[Terrace]

If Humanity somehow makes it 1000 more years and we don't figure out how to build a better battery, I'm going to be immensely disappointed.

If we're still rolling with liquid-state lithium-ion batteries in the year of our lord 3000 my skeleton or ghost or whatever's left shall rise up and declare the Human Race as failed, and I don't care if we terraform Mars, build a space elevator to the moon, and start up a Dyson Swarm all in the same week.

Well look at it this way. That 3PPH figure? It assumes you're not only using the built-in radio to talk, but also running the Infrared Scanner, Night Vision gear, Rangefinder, AND Ultrasonic Detector all at the same time. For an hour, without pause.

In reality, you'd probably leave everything but the radio off during the daytime, and you'd only activate the assorted detection modes when you actually need them. Otherwise, you'd leave those extra features off because they'd be sucking down battery life for no purpose. Can someone tell us what the battery life of modern Night Vision gear is like, and how heavy the battery is? Because many of those other modes are likely to be just as, if not more, power-hungry. Can you find a single battery today that weighs 20 grams that can power all that for over an hour of continuous use?

If not, then Micro Power Packs are still better, even with the nerfing proposed in this topic.

[Daryk]

Well, the AC-PVS-7 system claims it can get 55 hours out of 2 AA batteries.

And I feel compelled to repeat that "power points" represent quite a lot of energy.  Laser weapons are hogs.

[Terrace]

Well, the AC-PVS-7 system claims it can get 55 hours out of 2 AA batteries.

And I feel compelled to repeat that "power points" represent quite a lot of energy.  Laser weapons are hogs.

55 hours for just Night Vision for a minimum of 30g of batteries (though more like 46-62g), with the power drain likely skyrocketing as more stuff is added. Yeah, Micro Power Packs being way more energy dense than regular AA batteries for their size is a fair assumption.

And I'm not arguing about "power points" representing a lot of energy. I'm just diving into the nitty-gritty on how to reconcile the canon power requirements of stuff that requires Micro Power Packs with the chart posted here because I find it an amusing mental exercise.

[Retry]

Well look at it this way. That 3PPH figure? It assumes you're not only using the built-in radio to talk, but also running the Infrared Scanner, Night Vision gear, Rangefinder, AND Ultrasonic Detector all at the same time. For an hour, without pause.

Today's rangefinders may have an average power consumption of ~7W http://www.eecs.ucf.edu/seniordesign/su2015fa2015/g02/doc/Laser-Rangefinder.pdf

A night-vision gear might run on batteries with 4Wh capacity with a lifespan of about 30 hours.  That's an average power consumption of .133W.
https://tnvc.com/shop/tnvdtnvg-dual-tube-night-vision-goggle/?doing_wp_cron=1562861665.9671089649200439453125
https://www.batteryspace.com/CR123A-Batteries.aspx

A clock radio can consume up to 2W.  A DAB radio, 5-9W, so split the difference and get 7W.
https://www.daftlogic.com/information-appliance-power-consumption.htm

Infrared scanner, now it's really getting hard to find power consumption information on this.  It sounds similar in concept to the night-vision equipment (take EM waves from a spectrum you can't see and convert it to something you can), so we'll estimate it at the same power consumption level of .133W

Ultrasonic Detector, I don't know.  Closest thing I can find is this thing.  P=I*V, for V=5.5V and I=5mA, P=.0275W, which would imply that an ultrasonic detector thingy wouldn't have all that much energy consumption overall.
https://www.dfrobot.com/product-1057.html

So if all of these theoretical equipment were running the whole shebang would have a total consumption of about 14.3W.

A lithium-ion battery has a specific energy of 100 Wh/kg on the low end and 265 Wh/kg on the high.
For a 20g device, that's anywhere from 2 Wh to 5.3 Wh.  Only enough for about a third of an hour operating all of these equipment at the same time, assuming we're still running on these equipment in the modern day without any efficiency improvements and we're still using liquid Li-Ion batteries.

I would hope that sometime in the future we're at least able to make solid-state batteries with much higher energy densities.  Or even Lithium-air batteries, which has a theoretical specific energy of 11,140 Wh/kg.  Even a crappy futuristic Li-Air battery that gets only 1/10th of that would run all those equipment constantly for a few hours.

But even with our primitive modern tech, we can get pretty close.  This is a 500 Wh/kg battery, which downsized to 20g would mean it would have 10 Wh of energy available.  That'd feed the system operating constantly for 40 minutes at least.  If our futuristic radio or futuristic rangefinder makes even decent improvements by the 31st century then we'd be at well over an hour.
https://sionpower.com/products/

[Daryk]

I did look at Li-Air batteries in the course of drawing up the table.  I lost the thumb drive I had the spreadsheet on, but I did discuss the details with Cray.  I think my estimates are overall in line with the BT universe.

[Daryk]

Having just watched a video about solid state batteries, I think we're still on track.  Solid state batteries are expected to have up to 2.5 times the energy density of existing batteries.

[Daryk]

Update!  Samsung announced on 10 March 2020 that they have made a battery with 900Wh/L: https://news.samsung.com/global/samsung-presents-groundbreaking-all-solid-state-battery-technology-to-nature-energy

I'm trying to find that in terms of Wh/kg, but haven't yet.  At the very least, it exceeds the projected energy density of solid state batteries I was looking at when I first put this together.

And a research paper from last year seems to indicate the top end for solid state batteries could be as high as 2,500 Wh/kg: https://cafe.foundation/blog/superionic-batteries-are-we-there-yet/

[Daryk]

Two years later, Lithium-Sulfur batteries appear to be able to edge solid state ones by a hair at 2,567 Wh/kg: https://www.nature.com/articles/s41560-022-01001-0#:~:text=Owing%20to%20multi%2Delectron%20redox,%E2%89%A5600%20Wh%20kg%E2%88%921.

[Daryk]

And another 18 months on, it appears they've found a way to replace graphite with silicon (nanotechnology FTW!): https://www.youtube.com/watch?v=YJ4pg_exdvs

The main company featured in the video is claiming 450 Watt-hours/kg and 1,150 W-h/liter.  While well short of the theoretical limits above, these guys are actually making batteries, so it's still progress.

[beachhead1985]

I love this thread.

[Daryk]

Thanks!  If you find any similar tech updates, please post them here! :)

[Daryk]

Another 9 months on, and COMMERCIAL production batteries are now over 100 Wh/kg: https://www.youtube.com/watch?v=9AZRPItAsfA

Still a long way to the theoretical limits, but impressive nonetheless! :)

[Maingunnery]

Here is a good context video: https://www.youtube.com/watch?v=2eIPHX-NpMM

[Daryk]

She's always good for that... :)