I bought 2 car emergency start battery packs from Amazon. One has about 15.5 volts on the open circuit battery cables. It also has one USB port that is labled for 5 volts and 9 volts. Another port labled 12 Volta 10 amps. That port puts out about 15.5 volts open circuit. The other pack has 11.7 volts at the battery cable, then a USB port labled 5 v, 9v, 12 V with lower amps for the higher voltage. There ia another 12 volt port at 10 amps that puts out 11.7 volts. How does the USB port know what voltage to put out and more important how does it regulate that ? The second pack also charges off a 5 volt usb port. It must havve a boost inverter built in ?
car emergency start battery
Started by ●July 2, 2023
Reply by ●July 2, 20232023-07-02
On 2023-07-02 21:46, Ralph Mowery wrote:> > I bought 2 car emergency start battery packs from Amazon. One has about > 15.5 volts on the open circuit battery cables. It also has one USB port > that is labled for 5 volts and 9 volts. Another port labled 12 Volta 10 > amps. That port puts out about 15.5 volts open circuit. > > The other pack has 11.7 volts at the battery cable, then a USB port > labled 5 v, 9v, 12 V with lower amps for the higher voltage. There ia > another 12 volt port at 10 amps that puts out 11.7 volts. > > > How does the USB port know what voltage to put out and more important > how does it regulate that ? > > The second pack also charges off a 5 volt usb port. It must havve a > boost inverter built in ?The USB ports have to be connected to corresponding USB ports on chargers or batteries, and they negotiate what voltage to put there and how much current to draw. It is not just dumb electronics. https://en.wikipedia.org/wiki/USB https://en.wikipedia.org/wiki/USB_hardware#USB_Power_Delivery -- Cheers, Carlos.
Reply by ●July 2, 20232023-07-02
On Sunday, July 2, 2023 at 3:46:53 PM UTC-4, Ralph Mowery wrote:> I bought 2 car emergency start battery packs from Amazon. One has about > 15.5 volts on the open circuit battery cables. It also has one USB port > that is labled for 5 volts and 9 volts. Another port labled 12 Volta 10 > amps. That port puts out about 15.5 volts open circuit. > > The other pack has 11.7 volts at the battery cable, then a USB port > labled 5 v, 9v, 12 V with lower amps for the higher voltage. There ia > another 12 volt port at 10 amps that puts out 11.7 volts. > > > How does the USB port know what voltage to put out and more important > how does it regulate that ? > > The second pack also charges off a 5 volt usb port. It must havve a > boost inverter built in ?You should consult the manual for the characteristics of those ports. USB is 5V. There are many accessories that use the connector for power only and there is no data exchange.
Reply by ●July 2, 20232023-07-02
In article <nl19njxt2a.ln2@Telcontar.valinor>, robin_listas@es.invalid says...> > > How does the USB port know what voltage to put out and more important > > how does it regulate that ? > > > > The second pack also charges off a 5 volt usb port. It must havve a > > boost inverter built in ? > > The USB ports have to be connected to corresponding USB ports on > chargers or batteries, and they negotiate what voltage to put there and > how much current to draw. It is not just dumb electronics. > > https://en.wikipedia.org/wiki/USB > > https://en.wikipedia.org/wiki/USB_hardware#USB_Power_Delivery > > >I knew the data rates and currents were always being upgraded but did not know the voltage was raised in some cases. I had thought they were always just 5 volts. Did a little more research and found out there is a lot of electronics in those battery packs to do what I thought was a simple job of starting a car or providing voltage to charge a cell phone.
Reply by ●July 2, 20232023-07-02
On Sun, 2 Jul 2023 19:37:22 -0400, Ralph Mowery <rmowery42@charter.net> wrote:>In article <nl19njxt2a.ln2@Telcontar.valinor>, robin_listas@es.invalid >says... >> >> > How does the USB port know what voltage to put out and more important >> > how does it regulate that ? >> > >> > The second pack also charges off a 5 volt usb port. It must havve a >> > boost inverter built in ? >> >> The USB ports have to be connected to corresponding USB ports on >> chargers or batteries, and they negotiate what voltage to put there and >> how much current to draw. It is not just dumb electronics. >> >> https://en.wikipedia.org/wiki/USB >> >> https://en.wikipedia.org/wiki/USB_hardware#USB_Power_Delivery >> >> >> > >I knew the data rates and currents were always being upgraded but did >not know the voltage was raised in some cases. >I had thought they were always just 5 volts. > >Did a little more research and found out there is a lot of electronics >in those battery packs to do what I thought was a simple job of starting >a car or providing voltage to charge a cell phone.Project Farm did a study of these units. Joe Gwinn
Reply by ●July 2, 20232023-07-02
On Sun, 2 Jul 2023 14:52:18 -0700 (PDT), Fred Bloggs <bloggs.fredbloggs.fred@gmail.com> wrote:>On Sunday, July 2, 2023 at 3:46:53?PM UTC-4, Ralph Mowery wrote: >> I bought 2 car emergency start battery packs from Amazon. One has about >> 15.5 volts on the open circuit battery cables. It also has one USB port >> that is labled for 5 volts and 9 volts. Another port labled 12 Volta 10 >> amps. That port puts out about 15.5 volts open circuit. >> >> The other pack has 11.7 volts at the battery cable, then a USB port >> labled 5 v, 9v, 12 V with lower amps for the higher voltage. There ia >> another 12 volt port at 10 amps that puts out 11.7 volts. >> >> >> How does the USB port know what voltage to put out and more important >> how does it regulate that ? >> >> The second pack also charges off a 5 volt usb port. It must havve a >> boost inverter built in ? > >You should consult the manual for the characteristics of those ports. USB is 5V. There are many accessories that use the connector for power only and there is no data exchange.Classic USB was 5 volts. Newer versions can negitiate for 20 or 48, up to 240 watts.
Reply by ●July 3, 20232023-07-03
On Sunday, July 2, 2023 at 8:20:56 PM UTC-4, John Larkin wrote:> On Sun, 2 Jul 2023 14:52:18 -0700 (PDT), Fred Bloggs > <bloggs.fred...@gmail.com> wrote: > >On Sunday, July 2, 2023 at 3:46:53?PM UTC-4, Ralph Mowery wrote: > >> I bought 2 car emergency start battery packs from Amazon. One has about > >> 15.5 volts on the open circuit battery cables. It also has one USB port > >> that is labled for 5 volts and 9 volts. Another port labled 12 Volta 10 > >> amps. That port puts out about 15.5 volts open circuit. > >> > >> The other pack has 11.7 volts at the battery cable, then a USB port > >> labled 5 v, 9v, 12 V with lower amps for the higher voltage. There ia > >> another 12 volt port at 10 amps that puts out 11.7 volts. > >> > >> > >> How does the USB port know what voltage to put out and more important > >> how does it regulate that ? > >> > >> The second pack also charges off a 5 volt usb port. It must havve a > >> boost inverter built in ? > > > >You should consult the manual for the characteristics of those ports. USB is 5V. There are many accessories that use the connector for power only and there is no data exchange. > Classic USB was 5 volts. Newer versions can negitiate for 20 or 48, up > to 240 watts.A can't believe that crummy little connector will support even 2 Amp without getting hot eventually.
Reply by ●July 3, 20232023-07-03
On 2023-07-03 15:29, Fred Bloggs wrote:> On Sunday, July 2, 2023 at 8:20:56 PM UTC-4, John Larkin wrote: >> On Sun, 2 Jul 2023 14:52:18 -0700 (PDT), Fred Bloggs >> <bloggs.fred...@gmail.com> wrote: >>> On Sunday, July 2, 2023 at 3:46:53?PM UTC-4, Ralph Mowery wrote: >>>> I bought 2 car emergency start battery packs from Amazon. One has about >>>> 15.5 volts on the open circuit battery cables. It also has one USB port >>>> that is labled for 5 volts and 9 volts. Another port labled 12 Volta 10 >>>> amps. That port puts out about 15.5 volts open circuit. >>>> >>>> The other pack has 11.7 volts at the battery cable, then a USB port >>>> labled 5 v, 9v, 12 V with lower amps for the higher voltage. There ia >>>> another 12 volt port at 10 amps that puts out 11.7 volts. >>>> >>>> >>>> How does the USB port know what voltage to put out and more important >>>> how does it regulate that ? >>>> >>>> The second pack also charges off a 5 volt usb port. It must havve a >>>> boost inverter built in ? >>> >>> You should consult the manual for the characteristics of those ports. USB is 5V. There are many accessories that use the connector for power only and there is no data exchange. >> Classic USB was 5 volts. Newer versions can negitiate for 20 or 48, up >> to 240 watts. > > A can't believe that crummy little connector will support even 2 Amp without getting hot eventually.https://en.wikipedia.org/wiki/USB_hardware#USB_Power_Delivery -- Cheers, Carlos.
Reply by ●July 3, 20232023-07-03
On Monday, 3 July 2023 at 14:29:19 UTC+1, Fred Bloggs wrote:> On Sunday, July 2, 2023 at 8:20:56 PM UTC-4, John Larkin wrote: > > On Sun, 2 Jul 2023 14:52:18 -0700 (PDT), Fred Bloggs > > <bloggs.fred...@gmail.com> wrote: > > >On Sunday, July 2, 2023 at 3:46:53?PM UTC-4, Ralph Mowery wrote: > > >> I bought 2 car emergency start battery packs from Amazon. One has about > > >> 15.5 volts on the open circuit battery cables. It also has one USB port > > >> that is labled for 5 volts and 9 volts. Another port labled 12 Volta 10 > > >> amps. That port puts out about 15.5 volts open circuit. > > >> > > >> The other pack has 11.7 volts at the battery cable, then a USB port > > >> labled 5 v, 9v, 12 V with lower amps for the higher voltage. There ia > > >> another 12 volt port at 10 amps that puts out 11.7 volts. > > >> > > >> > > >> How does the USB port know what voltage to put out and more important > > >> how does it regulate that ? > > >> > > >> The second pack also charges off a 5 volt usb port. It must havve a > > >> boost inverter built in ? > > > > > >You should consult the manual for the characteristics of those ports. USB is 5V. There are many accessories that use the connector for power only and there is no data exchange. > > Classic USB was 5 volts. Newer versions can negitiate for 20 or 48, up > > to 240 watts. > A can't believe that crummy little connector will support even 2 Amp without getting hot eventually.Some USB-C connectors are rated at 5A! John
Reply by ●July 3, 20232023-07-03
On Mon, 3 Jul 2023 06:29:14 -0700 (PDT), Fred Bloggs <bloggs.fredbloggs.fred@gmail.com> wrote:>On Sunday, July 2, 2023 at 8:20:56?PM UTC-4, John Larkin wrote: >> On Sun, 2 Jul 2023 14:52:18 -0700 (PDT), Fred Bloggs >> <bloggs.fred...@gmail.com> wrote: >> >On Sunday, July 2, 2023 at 3:46:53?PM UTC-4, Ralph Mowery wrote: >> >> I bought 2 car emergency start battery packs from Amazon. One has about >> >> 15.5 volts on the open circuit battery cables. It also has one USB port >> >> that is labled for 5 volts and 9 volts. Another port labled 12 Volta 10 >> >> amps. That port puts out about 15.5 volts open circuit. >> >> >> >> The other pack has 11.7 volts at the battery cable, then a USB port >> >> labled 5 v, 9v, 12 V with lower amps for the higher voltage. There ia >> >> another 12 volt port at 10 amps that puts out 11.7 volts. >> >> >> >> >> >> How does the USB port know what voltage to put out and more important >> >> how does it regulate that ? >> >> >> >> The second pack also charges off a 5 volt usb port. It must havve a >> >> boost inverter built in ? >> > >> >You should consult the manual for the characteristics of those ports. USB is 5V. There are many accessories that use the connector for power only and there is no data exchange. >> Classic USB was 5 volts. Newer versions can negitiate for 20 or 48, up >> to 240 watts. > >A can't believe that crummy little connector will support even 2 Amp without getting hot eventually.The c connector is the first USB connector that makes sense. It uses several pins for power. I assume that someone sells the negotiation chips to let us design a box that gets lots of power from USB. There are chips and baby boards for PoE, a similar situation. PoE has the advantage that lots of power is available from even the wimpiest compliant hubs.
