Lets say it is a 20Amp powerbank with the sole purpose when built to charge phones and possibly run low current devices.
Consider this unit as the example, 20000mAh Power Bank, ROMOSS Sense 6 Plus USB C Portable Charger with PD 18W QC 3.0
Lets say it is a 20Amp powerbank with the sole purpose when built to charge phones and possibly run low current devices.
Consider this unit as the example, 20000mAh Power Bank, ROMOSS Sense 6 Plus USB C Portable Charger with PD 18W QC 3.0
A big discrepancy, first you say 20Amp then 18W, which, at 5V, is 3.6A.
Can you do it? Of course, most stupid ideas are possible. Just wire enough powerbanks in series and parallel. For example, three in series for 15V, 3.6A. Then hundred of these (so 300 total) in parallel for 15V, 360A max. Or oh well, use 600 powerbanks for 15V, 720A for smaller risk of cascading overcurrent detection and shutdown of the units. I'd suggest adding small value balancing resistors, one per each 3 powerbanks in series, such that they drop e.g. 0.5V at 3.6A.
If you use USB-C port, you can use 15V PD triggers, but for 18W it can provide just 1.2 Amps at max. So, for 200 Amps you will needs to connect 200/1.2 = 167 power banks in parallel. But be careful, 15V may damage some electronics on your car. Most of all it will be ok, because it was designed for 14.4V and even a little more, but who knows...
[2] The second is can a car be JUMP started with a little power bank with the original car battery still in the car.
The answer to #2 is YES but it takes time to charge the original car battery with the jump pack first, and it could take as long as an
withstand even higher voltage spikes (at least 30V). I would therefore suspect 15V isn't going to be an issue
Alternators adjust their output voltages based on temperature, as fully charging the lead acid battery in cold conditions (e.g. -20degC) requires voltage of 15...16V (e.g. the magical 14.4V number won't cut it) in order to not sulfate and self-destruct in matter of months, which is exactly why it's normal to have 15V on the system, and quite obviously everything connected to the car needs to deal with it.
It depends on the car. On Toyota Corolla I didn't seen alternator voltage above 14.4V.
Yes, I measured it in summer. I'm not sure if it makes difference depends on temperature, needs to check it.
[2] The second is can a car be JUMP started with a little power bank with the original car battery still in the car.
The answer to #2 is YES but it takes time to charge the original car battery with the jump pack first, and it could take as long as anIt depends on the definition of "little".
Assuming a fully depleted car battery of, roughly, say, 800 Wh, and not even such a small powerbank of, say, 60 Wh, it becomes clear that such a powerbank does not have a sufficient amount of energy to charge the car battery to the level at which it can output the current required to start the engine sustained during a few seconds.
Alternators adjust their output voltages based on temperature, as fully charging the lead acid battery in cold conditions (e.g. -20degC) requires voltage of 15...16V (e.g. the magical 14.4V number won't cut it) in order to not sulfate and self-destruct in matter of months, which is exactly why it's normal to have 15V on the system, and quite obviously everything connected to the car needs to deal with it.
It depends on the car. On Toyota Corolla I didn't seen alternator voltage above 14.4V. But on another car type I was seen 15V and more... I'm not sure if these 15V is due to broken/failed alternator voltage regulator, or just by design.
Usually alternator has voltage regulator which can control alternator output voltage. It control it by change current through special alternator coils. Sometimes this regulator is failed and alternator can push high voltage on the battery. In such case it leads to a faster death of the battery due to overcharge. The bad thing is that all works ok, and you can even don't suspect that alternator regulator is failed, you can replace battery, it it also will be dead soon. This is why it is important to check alternator voltage in case if your battery is dead too quickly.
But there is also modern Ca/Ca batteries, which may require higher charge voltage than 14.4V, so it's not easy question.
Yes, 15V looks ok, for all vehicle electronics, because it should survive even higher voltage pulses. But who knows, may be some cars don't like when voltage is 15V and more...
What is "PD fooler ccts"?
Hi All,
Thanks for all the replies and the interesting detours this question created.
My understanding is it will never charge a 12 v lead acid battery due to the output being only 5V.
So because it is a voltage Mismatch the 12V lead-acid battery requires a charging voltage higher than 12V, typically around 13.2V to 14.4V depending on the charging stage. A 5V supply is too low to charge the battery effectively.
I got hold of some PD fooler ccts just to see if I could get 12-15V but on my initial test I didn't get any readings, either I wired it wrong or aliexpress sent me a dud?
Again thanks to all for the answers it was quite an interesting discussion.
Cheers, LateralNw
A Lead acid battery is considered to have 0% capacity at 11.59V.
The car's alternator generates more than enough electricity for the car when the engine is running. The battery is only needed to start the engine and if the car can be stated with the little power bank why do they put such a large battery in the car?
The car's alternator generates more than enough electricity for the car when the engine is running. The battery is only needed to start the engine and if the car can be stated with the little power bank why do they put such a large battery in the car?
you might even run you battery flat when driving only short distances, which drains the battery more on a motor start than the recharging from driving.
Some cars do not start to generate electrical energy with the alternator as soon as the car starts. This is very strange but it's probably meant to protect the alternator or something. It could take as long as 5 seconds as my old Volvo did. That means you need to supply power for a time longer than the time it takes for the engine to start. If you don't the engine just shuts right off again. It's a real pain in the neck.
This is legit. Supercap based jump starters definitely work.
The amount of energy required to start an engine is very -- surprisingly -- low. Even a half-dead car battery contains more than enough of it. But the problem is that this energy must be released in a very short time, and this is what a depleted or degraded lead-acid car battery is not capable of. A sufficiently large supercap bank, OTOH, can do it, and with a proper charging circuit it can be charged from any low-power source, including a powerbank, that would never be able to start an engine on its own.
Just a quick reply...
Some cars do not start to generate electrical energy with the alternator as soon as the car starts. This is very strange but it's probably meant to protect the alternator or something. It could take as long as 5 seconds as my old Volvo did. That means you need to supply power for a time longer than the time it takes for the engine to start. If you don't the engine just shuts right off again. It's a real pain in the neck. Some jump starters will not start the car because of this because the engine starts, then the jump starter turns off, then the car stalls. Then you have to reset the jump starter to try again but it will just do the same thing again because of that delay.