Idea: Watercooled wireless charging.

[Avaviel]

I've been considering why Linus only slow charges, and doesn't use wireless. It is because of the heat. It would be neat to modify one of those cheaper apple watch/iPhone charges to have a cooling loop and a small radiator. You could even track the battery health, and compare it to those who wireless charge without cooling.


Also, same idea but include a fan. Maybe a 3d printed mount for one. I think this is what I'd try first for my watch.

[jaslion]

Its because it keeps the battery healthy.

 

Cooling your phone whilst fast charhing does not help lessen battery wear much as the heat is still being generated inside the batteries core.

 

So simply put to keep a healthy battery you keep the amps low and have a bit of patience (like even a 5v 2a charger charges almost any phone in under 2 hours)

[ccnow]

jaslion has it right.

 

The heat isn't what's killing the battery. It's just the symptom you see. The battery wears from the charge/discharge cycle and doing that faster or slower impacts the wear. The heat is a side effect. It's the visible part of the battery wear. Removing the heat from the charge cycle is like pulling your shirt over a stab wound. You're covering up the visible evidence, but the damage is still happening underneath.

 

---EDIT---

 

As an aside, heat can damage a battery as well, but not at the temperatures you see while wireless charging. I wanted to add this because keeping the battery below that point is part of the reason for the radiators and cooling systems on something like an electric car. In that use case the heat of the charge/discharge COULD be hot enough to damage the batter if unchecked. Your phone isn't reaching those temperatures though.

[Avaviel]

So you'd need cooling INSIDE the battery to do any good?

[ccnow]

7 minutes ago, Avaviel said:

So you'd need cooling INSIDE the battery to do any good?

No, that's what I'm trying to say. The chemical process is what creates the heat AND ages the battery. The heat itself isn't what's damaging the battery, the heat is just your signal that the battery is being damaged.

 

Your check engine light for instance isn't the problem with your car. It's your signal that there is a problem with your car. You can hide that signal and remove the light, but the problem is still there. Removing the light is like removing the heat.

[jaslion]

11 minutes ago, Avaviel said:

So you'd need cooling INSIDE the battery to do any good?

No the chemical reaction creates heat and adding more current basically makes the reaction happen harder which uses more of the finite resources it has, so to say. So basically like driving a car.

 

If you drivr 50km/h and you need to be somewhere 100km away it will take you 2 hours. However for example you only consume 2.3L/100km at this speed.

 

Now you can get there in 1 hour at 100km/h but you use 6.7L/100km.

 

You got there quicker but at a cost. Same for batteries.

 

 

[NoNameCola]

On 1/4/2024 at 6:27 PM, Avaviel said:

I've been considering why Linus only slow charges, and doesn't use wireless. It is because of the heat. It would be neat to modify one of those cheaper apple watch/iPhone charges to have a cooling loop and a small radiator. You could even track the battery health, and compare it to those who wireless charge without cooling.


Also, same idea but include a fan. Maybe a 3d printed mount for one. I think this is what I'd try first for my watch.

Water cooling would be excessive. Some of Samsung's fast wireless chargers have a fan to keep things cool while charging. 

 

To the other people in the thread, heat does damage battery cells. That's why the Nissan Leaf has such poor degradation while the first Model S' off the line still has decent battery capacity left. Nissan didn't have thermal management for the battery pack and every time it got cold outside or too hot if you used the CHAdeMO fast charging. On a hot day if you walk past a Tesla that's supercharging you can hear the heat pump system going full blast to cool the battery pack.

 

Lithium polymer batteries generally like being between 15-35 C. A simple fan inside the charger and maybe use NFC to report the temperatures to the fan in order to ramp it up/down. 

 

Personally I use an IKEA wireless charger that only does 5 W, my phone doesn't get super warm and I don't wear out the charging port. It's fast enough for me to wake up with a full battery in the morning. 

[jaslion]

On 1/11/2024 at 7:44 PM, NoNameCola said:

Water cooling would be excessive. Some of Samsung's fast wireless chargers have a fan to keep things cool while charging. 

 

To the other people in the thread, heat does damage battery cells. That's why the Nissan Leaf has such poor degradation while the first Model S' off the line still has decent battery capacity left. Nissan didn't have thermal management for the battery pack and every time it got cold outside or too hot if you used the CHAdeMO fast charging. On a hot day if you walk past a Tesla that's supercharging you can hear the heat pump system going full blast to cool the battery pack.

 

Lithium polymer batteries generally like being between 15-35 C. A simple fan inside the charger and maybe use NFC to report the temperatures to the fan in order to ramp it up/down. 

 

Personally I use an IKEA wireless charger that only does 5 W, my phone doesn't get super warm and I don't wear out the charging port. It's fast enough for me to wake up with a full battery in the morning. 

Yes absolutely heat does damage batteries. However in the case of the phone it's not really doable to cool it. In a electric car you have to cool the batteries because they will get too hot due to there being so many which can be disastrous. But again if you take 1 of the batteries and were to charge it outside the battery pack in the car it won't be heat doing the damage but the current at which it is charging.

 

Of course bigger batteries can handle higher currents better and such. But the general rule is still faster charging makes a more intense chemical reaction which causes more wear. Cooling is needed if your battery can get too hot that it gets to self damaging temps. However this can be avoided by charging slower normally and this is also just healthier for the battery in general.

 

I avoided making it more complex for op but you are entirely correct. Big banks of batteries need cooling. Electric bikes nowadays also often have a fan for the battery too and such when they have a faster charging option.