New Research - Drone Charging Speed

[SANTIMEL]

Goal

Improve the dynamics of the gameplay

Situation

Once discharged, not only do drones become slow. So you also have to approach each of them.
And wait, for each of them to charge up.

Decision

Add a new type of research. Which increases the charging speed of the drones. Up to an instantaneous one.

[Trific]

You can mine bots out of the air (right click them). Then they are taken into inventory and recharged instantly.

[ChefOfRamen]

Hard no. This would make logistic bots even more overpowered than they already are.

What kind of situation are you running into that this would be important?

[Koub]

This would make logistic bots even more overpowered than they already are.

Overpowered compared to what ? The 4th tier of ultrafast belts ? The new stack inserters ? Bots give convenience and good spike capability where belts give throughput capability. Once bots get enough speed upgrades, the number of roboports they need to be continuously powered, and the charging time/transport time ratio get prohibitive.

I'd be OK with something that would help the bots scale a tad bit better in the endgame, but I do agree it should be carefully balanced not to make the bots OP compared to the other logistic options.

[Illiander42]

I'd be OK with something that would help the bots scale a tad bit better in the endgame, but I do agree it should be carefully balanced not to make the bots OP compared to the other logistic options.

My vote is for battery size. Let them travel longer without needing to recharge.

Most of the charging time is in that last slow crawl to be over the charging point, so reducing how often they need to do that would give them more uptime, while also making large-scale construction jobs smoother.

[FuryoftheStars]

I'd be OK with something that would help the bots scale a tad bit better in the endgame, but I do agree it should be carefully balanced not to make the bots OP compared to the other logistic options.

My vote is for battery size. Let them travel longer without needing to recharge.

Most of the charging time is in that last slow crawl to be over the charging point, so reducing how often they need to do that would give them more uptime, while also making large-scale construction jobs smoother.

^^ This

[Koub]

My vote is for battery size. Let them travel longer without needing to recharge.

Most of the charging time is in that last slow crawl to be over the charging point, so reducing how often they need to do that would give them more uptime, while also making large-scale construction jobs smoother.

I'm not totally sold on that one. The reason why robots come to a crawl when out of power is most likely because of an insufficient roboport density. Roboport density has to be raised as robot speed upgrades are researched, even at a constant bot number, because power consumption becomes dominated by the "per tile traveled through" component (5kJ/m), while the time based component becomes negligible (3kJ/s).

The quicker the bot, the faster it discharges, while the charging time remains constant => with a constant logibot number, the quicker they are, the more one has to add roboports until it becomes impractical.

[Illiander42]

Roboport density has to be raised as robot speed upgrades are researched, even at a constant bot number, because power consumption becomes dominated by the "per tile traveled through" component (5kJ/m), while the time based component becomes negligible (3kJ/s).

The quicker the bot, the faster it discharges, while the charging time remains constant => with a constant logibot number, the quicker they are, the more one has to add roboports until it becomes impractical.

Hang on, that sounds really counterintuitive. Can you do a worked example or something to make it obvious?

[Koub]

Hang on, that sounds really counterintuitive. Can you do a worked example or something to make it obvious?

Taken from this wiki page :

Energy consumption : 5 kJ/m
Drain : 3 kW (3 kJ/s)
Energy capacity : 1.5 MJ (electric), so 1500 kJ
The basic movement speed of logistic robots is 0.05 tiles/tick (3 tiles per second).

Taken from this wiki page :

Robot recharge rate : 4×1.0 MW (electric)

In other words, to recharge a robot's 1.5MJ capacity, 1.5s (flat) will be needed).

Taken from this wiki page, the speed bonus obtained from Worker robot speed research

Worker robot speed 5 : 240%
Worker robot speed 6 : 240% + 65%*(Level-5)

So a continuously flying robot :
- 0 speed upgrades : Consumption 15 kW from moving 3 m/s + 3kW/s drain = 18kW/s. Autonomy : 83.33s (1500/18). 1.8% time spent recharging. A roboport can power up to 222.2 robots (83.33/1.5)*4.
- 5 speed upgrades : Consumption 51 kW from moving 10.2 m/s + 3kW/s drain = 54 kW. Autonomy : 27.77s (1500/54). 5.1% time spent recharging. A roboport can power up to 74 robots (74/1.5)*4.
- 10 speed upgrades : Consumption 99.75 kW from moving 19.95 m/s + 3kW/s drain = 102.75 kW. Autonomy : 14.6s (1500/102.75). 9.3% time spent recharging. A roboport can power up to 38.9 robots (38.9/1.5)*4.
These are realistic numbers (10 speed upgrades is infinite research 5, so realistically attainable).
With level 15 speed upgrade, the robots get below 10s autonomy, one roboport can power up to 26.4 robots.
Above the - quite unrealistic - infinite research level 97 (102 speed upgrade), one roboport can power less than 4 robots flying continuously.

Other fun fact, with 0 upgrades, a robot can travel 250 tiles max. With infinitely many speed upgrades, it can approach 300 tiles only.

The spreadsheet is attached, feel free to proofread it, I'm no immune to mistakes .

[FuryoftheStars]

I wonder how something like this could affect any of this if made vanilla?
https://mods.factorio.com/mod/Robot_Battery_Research

I don't have the time right now myself to really look into any of it, but if no one else does in the next... 6?... hours, I'll try crunching some numbers.

I'm just not sure how I feel about increasing charge speed to the point where they just fly over the roboport and off they go with just a maybe 1 tick pause....

[SoShootMe]

The quicker the bot, the faster it discharges, while the charging time remains constant => with a constant logibot number, the quicker they are, the more one has to add roboports until it becomes impractical.

For a given cargo size, if you ignore the 3kW drain (which is reasonable after the first few speed upgrades), the energy to move each item a given distance is just determined by the constant 5kJ/tile. On that basis, the total item throughput determines the total power required for charging robots, and hence the number of roboports; robot speed doesn't come into it.

[Koub]

The quicker the bot, the faster it discharges, while the charging time remains constant => with a constant logibot number, the quicker they are, the more one has to add roboports until it becomes impractical.

For a given cargo size, if you ignore the 3kW drain (which is reasonable after the first few speed upgrades), the energy to move each item a given distance is just determined by the constant 5kJ/tile. On that basis, the total item throughput determines the total power required for charging robots, and hence the number of roboports; robot speed doesn't come into it.

Your statement is totally true, but doesn't convey what I find frustrating gameplay wise : At the beginning of a game, robots are very slow, and one needs tons of them to achieve a significant throughput with few roboports. As robot speed is researched, the robots are individually able to do a lot more carrying in a given time frame, but without additional roboports, their throughput quickly plateaus, the robots spending an increasing time queuing for recharge. Adding more roboports does the trick at the beginning, but the increase in needed recharge capacity quickly exceeds what's practical.

That's why I would welcome something to mitigate that : Charging speed upgrade or flight efficiency would be good candidates. Battery size, not so much, as a bigger battery would need more time to recharge, the very marginal gain would be that robots would have to do less trips to a roboport for recharge (on average), so spend slightly more time carrying stuff.

[mmmPI]

I wonder how something like this could affect any of this if made vanilla?
https://mods.factorio.com/mod/Robot_Battery_Research

I don't have the time right now myself to really look into any of it, but if no one else does in the next... 6?... hours, I'll try crunching some numbers.

I'm just not sure how I feel about increasing charge speed to the point where they just fly over the roboport and off they go with just a maybe 1 tick pause....

I haven't crunched any numbers but i played with this mod, i felt like it allowed me to have a very large network (compared to without the research), in my opinion, the main advantages it gave was that bots travelling very long distance would only charge once instead of 7 time for example. Allowing "faster construction" on very large scale. It was for self expanding solar grid surrounding my base that was a small isolated network in the middle.

It doesn't make recharge faster, but occurring less frequently. I have read Koub's numbers. I'm not sure how fast were my robots compared to how much the battery was increased, but i suppose the game can guide players to balance them out. If a player research "speed" a lot, it will require an increased robotport density, but with larger battery, robots have an extended range of research/access to more roboport "on average".

I suppose a more rigorous math way to way would be the more you "increase battery" the higher becomes the cap of 300 tiles that is the max distance reached before the robot need to recharge no matter at its most optimal speed.

It did felt to me like robots in general were made a lot more powerful/ requiring less planning to make it work at large scale but that is not the same concern as "personnal robots running out of batteries are annoying". There could be a different research , or who knows, high quality personnal roboports ? impacting the recharge speed for only personnal robots.

Maybe it was just due to solar grid not requiring high density of robot to make it work compared to train stations or mining outpost so it only increased something that was going to work anyway when i used the mod and it biais my views^^.

[FuryoftheStars]

A (fast) play with the numbers (adjusting the time spent charging to account for changing battery size) in that spreadsheet shows that there is no change in the "Time ratio spent recharging" or "Maximum swarm by roboport without queue", even though the "Maximum travel distance" does increase, which kind of makes sense. If the time spent charging were a static 1.5s regardless of battery size/the charging speed were to change with the battery size, then this would make a difference.

[FuryoftheStars]

Ok, so yeah, with increased battery size just comes increased travel distance before recharge is needed, but seems it still charges at the same rate, with the bigger battery it takes longer thus cancels itself out with how long everything spends charging (on strict paper).

You would need to increase charging speed in order for the increased battery size to also start to counter-act the affect increased worker speed has on swarming of roboports.

That said, from the discussions section of that mod I linked to before, Klonan said (6 years ago) that changing the rate in which robots recharge was not possible. Obviously this could be changed, but the question there would be what affect, if any, would this potentially have on game performance if that value was suddenly no longer static?

[CyberCider]

I briefly scrolled through these replies, and I don’t believe anyone has brought it up yet, so I’m just dropping in to remind you all: Higher quality robots will have larger batter capacity, and higher quality roboports will have an increased charge speed

Both of these bonuses will be determined by the standard quality effect formula (+30%, +60%, +90%, +150%)

[Koub]

I briefly scrolled through these replies, and I don’t believe anyone has brought it up yet, so I’m just dropping in to remind you all: Higher quality robots will have larger batter capacity, and higher quality roboports will have an increased charge speed

Both of these bonuses will be determined by the standard quality effect formula (+30%, +60%, +90%, +150%)

You're right, I totally forgot quality. Might be just what's needed to help scale robots in the endgame.

[Illiander42]

I briefly scrolled through these replies, and I don’t believe anyone has brought it up yet, so I’m just dropping in to remind you all: Higher quality robots will have larger batter capacity, and higher quality roboports will have an increased charge speed

Both of these bonuses will be determined by the standard quality effect formula (+30%, +60%, +90%, +150%)

You're right, I totally forgot quality. Might be just what's needed to help scale robots in the endgame.

If I'm understanding that right, that won't change time to charge if everything is the same quality, so will act similarly to reducing the cost per tile?

But also all this math says that you want to upgrade roboports before robots?

Am I getting that right?

[FuryoftheStars]

If I'm understanding that right, that won't change time to charge if everything is the same quality, so will act similarly to reducing the cost per tile?

Correct, though by increasing the distance they can go while keeping charge time the same, you will be decreasing the time ratio they spend charging, and thus in theory reduce the number of roboports you need for the same number of robots (for the strict purposes of recharging).

But also all this math says that you want to upgrade roboports before robots?

You don't need to. While upgrading the robots first will result in longer charge times, they'll also be airborne longer, so the ratio of flying to charging should remain the same. Ultimately, the same number of (Q1) roboports will still be able to service the same number of robots as previously.

[SoShootMe]

I briefly scrolled through these replies, and I don’t believe anyone has brought it up yet, so I’m just dropping in to remind you all: Higher quality robots will have larger batter capacity, and higher quality roboports will have an increased charge speed

Both of these bonuses will be determined by the standard quality effect formula (+30%, +60%, +90%, +150%)

This - a finite increase to charging power - seems like the "right" solution. This ultimately amounts to a throughput increase for the end-game (increasing the number of charging points would have a similar effect). I think an infinite research (as the OP suggested) would make robots the only end-game solution, and is therefore a bad idea.

Given the new belt tier and stacking (FFF-393) I think the net result is the belt/bot balance will nonetheless tip towards belts. Quality (FFF-375) is clearly stated as an expansion feature; it's not clear to me whether the new belt tier and stacking are also expansion features or 2.0 features, although I think the former.

But also all this math says that you want to upgrade roboports before robots?

I could well be missing something but as far as I can see, higher charging power enables higher sustained throughput from the same number of roboports (primarily useful for robot logistics, especially when you reach the limit of practical roboport density) while increasing battery capacity extends burst capability (primarily useful for personal logistics and construction); the benefits are close to orthogonal.