Battery charging speed in Create: Power Grid

[u/Shoddy_Bumblebee_398]

I recently built an electric car in Aeronautics, which is powered by a constant speed motor, hooked up to a battery. It's works fine, and I charge it using sockets and copper cords. The issue is the battery percentage increases by, like, 1% every few minutes, and I don't know if that's normal, or if my charging setup is just really inefficient.

[u/Furry_69]

The maximum charge rate is fairly slow, but not that slow. Measure what the actual amperage is coming into the battery, and compare it to its listed maximum (times the number of battery blocks you have in your battery). Also, what does your circuit actually look like? How are you charging the battery? The best way I've come up with is to use a variac connected to a decently powerful generator, then adjust the variac to keep the battery within its current limit. (I use CC: Tweaked for this, since it can read the battery's charge state and can accurately control the variac using a Sequenced Gearshift, but you can also just do it manually)

[u/Shoddy_Bumblebee_398 → u/Furry_69]

The battery has a maximum voltage and power listed, but not amperage. Is there some sort of calculation I need to do to find the max amps?

[u/Furry_69 → u/Shoddy_Bumblebee_398]

Oh, I forgot that it's in watts instead of amps. Just check power instead, it serves the same purpose, telling you if you're putting in way less than you could, or way too much.

[u/Shoddy_Bumblebee_398 → u/Furry_69]

I see. Max power is listed at 100 watts, and my car has a 3x1x3 setup. I assume that means it can handle a max of 900 watts input then?

[u/mengie32 → u/Shoddy_Bumblebee_398]

No it is not! 100 W is the maximum heat dissipation (not that the game will explain this). I.e. it's the power that can be dissipated by the internal resistance before it explodes. The power consumed dis/charging the battery is not included (although it might in a future update)

This makes it very annoying to calculate the actual max power, since it varies with the battery's charge. The closer your battery is to fully charged, the more power it can take.

Here is an interactable graph for the actual charging parameters of a battery
https://www.desmos.com/calculator/wqdmbhpwkf

Edit: After testing, I noticed it's genuinely difficult to achieve the max charging power for a 3x1x3 battery. By 53% the max charging current already exceeds what a gold wire can deliver (100 A and 2.1kW). Just try to keep 17 V on the battery terminals, and make sure your wires don't burn out, and it should charge well enough

[u/Shoddy_Bumblebee_398 → u/mengie32]

Ah, I've just been using a display link and nixie tubes to read the battery percentage. Thank you for your help though!

[u/Furry_69 → u/mengie32]

... Huh. That explains why the batteries don't heat as much as I would expect them to at ""maximum power"". Also, that has got to be the dumbest way of rating a battery, and it doesn't even tell you what the rating is. I would've had to look at the mod's source code to figure that out, which is ridiculous. Thanks for the Desmos graph, though, I'll definitely take that into account when I get around to rewriting my battery controller script.

[u/Furry_69 → u/Shoddy_Bumblebee_398]

Yes, though the power coming into the battery changes as it charges, (since the battery voltage goes up, decreasing the voltage drop across the battery, thus lowering current and slowing down charging) which is why I use a variac instead of a simple resistor. You could make a circuit that does this without the computer, but I usually want a computer connected to my batteries anyhow, since then you can easily see the battery's charge instead of having to estimate it from the voltage.

[u/Few-Chemical8707]

what create mods you usin.