document updated 2 months ago, on Nov 3, 2022
an any-voltage-input phone charger
The goal is to have a voltage regulator that can accept a very wide voltage input (a
buck-boost converter), and it can charge a cellphone at least.
The input could be a wide variety of things:
10 AA batteries (or AAA or C or D)
for 10 zinc-carbon batteries, the voltage range would be
~9 to ~15 volts for 10 alkaline batteries, the voltage range would be
6.2 to 15.9 volts a 9-volt zinc-carbon battery would have a voltage range of
~6 to 9 volts. a car battery (lead-acid
starter battery) would have a voltage range of ~11.6 to 12.8 volts.
If connected to a running vehicle, however, then you would see an alternator voltage of
13.9 to 14.8 volts. a 6 volt
lantern battery would have an actual voltage range of ?? to ~6.3 volts. All-electric vehicles have a battery voltage of
~400 to 800 volts, which will probably be outside the range of this project, unless they contain a 12 volt "cigarette lighter" outlet via step-down electronics. two voltage converters
The theory here is that 12 volts is SUCH a common voltage to use in vehicles that you probably have some electronics for it already — you probably have a phone modern fast-charger in your car, and you may even have a portable power station that charges from 12 volts.
(note that it's 12 v nominal, 11.6 to 14.8 v actual)
(there was an attempt to move to 24 volt or even
42 volt systems in consumer-level cars, but that didn't pan out for reasons; higher voltage systems may be found on some RVs, larger boats, and commercial/industrial/military vehicles)
Specific products include:
there are a
in the range of 25 to 200 watts, but they require >12 volt inputs TON of golf cart step-down converters golf cart converters that are both buck+boost:
brand "HomeLylife", input 8 to 40 volts, 72 watts
brand "Yipin", input 8 to 40 volts, 72 watts
brand "HomeLylife", input 8 to 40 volts, 138 watts at 13.8 volts out
This has lots of great reviews! (though that Amazon page has many semi-related products on it)
brand "Tobsun", input 8 to 40 volts, 138 watts at 13.8 volts out
may be a re-brand of the above?
brand "XWST", input 9 to 36 volts, with several products ranging from 120 to 360 watts
The reviews note some real problems. If input voltage drops too low, it's reported you need to restart it before it will resume operation.
brand "Valefod", input 8 to 36 volts, 128 watts
brand "Aoicrie", input 7 to 32 volts, 108 watts (adjustable voltage output too, but I likely wouldn't use that feature)
brand "JacobParts", input 5 to 32 volts, 80 watts (adjustable output voltage too) products that include an ammeter:
a single voltage converter
Obviously this would be more efficient. However, it would need to integrate the latest
fast-charge standards, which means it could lag behind a bit, if it sits in the emergency kit for too long.
fast-charge standard "QC 3.0", brand "DROK", input 6 to 32 volts, 24 watt output max
fast-charge standard "QC 3.0", brand "HiLetgo", input 6 to 32 volts
fast-charge standard "QC 3.0", brand ??, input 6 to 32 volts, four USB Type-A ports
fast-charge standard "none", brand "HiLetgo", input 6 to 20 volts, 15 watt output
AliExpress, fast-charge standard "PD", brand ??, input 3 to 24 volts, allegedly 100 watts but for $8 I don't believe that
random website, fast-charge standard "PD 3.0", brand ??, input 6 to 35 volts accessories
For the 12 volt version, I would want a female cigarette lighter socket.
For all of them, I would want a variety of battery-holders, including:
For all of them, if they don't include terminal blocks, then get a butt-terminal-block, to make it easier to connect various inputs to.