Neer to convert 5 volt dc to 42 volt

raggie33

*the raggedier*
Joined
Aug 11, 2003
Messages
13,794
Need a way to convert 5 volt USB DC to 42 volt DC any ideas of what I should buy?
 

scalpel_ninja

Flashlight Enthusiast
Joined
Sep 16, 2020
Messages
1,010
I wonder if stepping up that much in voltage would drop the current to a very low level? Are you planning to charge your electric bike/moped with the power?
 

raggie33

*the raggedier*
Joined
Aug 11, 2003
Messages
13,794
I wonder if stepping up that much in voltage would drop the current to a very low level? Are you planning to charge your electric bike/moped with the power?
That's exactly what I wanna do using my foldable solar panel
 

KITROBASKIN

Flashlight Enthusiast
Joined
Mar 28, 2013
Messages
5,511
Location
New Mexico, USA
Your solar panels do not have a 12 Volt DC output connection? That's ok if they don't but I am thinking you are unable to get there without additional battery storage that has 12V output then use an inverter to power the AC charger that came with your bike. Perhaps someone else has an idea, but thinking it will not be practical.

Be careful raggie.
 

orbital

Flashlight Enthusiast
Joined
Feb 8, 2007
Messages
4,359
Location
WI
+

5v usb to 42v is effectively impossible.
Even if you did it somehow, it would take like 2 weeks to charge your bike battery
because it would be similar to .0003A charging after converting.

What are the output/specs & connectors to your solar panel?? (not talking about the usb)

.....In your 'new favorite ride' thread, we gave a couple solar suggestions/thoughts & you never followed up.
 
Last edited:

SYZYGY

Enlightened
Joined
Sep 6, 2019
Messages
320
Your solar panels do not have a 12 Volt DC output connection? That's ok if they don't but I am thinking you are unable to get there without additional battery storage that has 12V output then use an inverter to power the AC charger that came with your bike. Perhaps someone else has an idea, but thinking it will not be practical.

Be careful raggie.

i would think that you wouldn't want an additional storage stage (and losses) for that meager amount of power
 

KITROBASKIN

Flashlight Enthusiast
Joined
Mar 28, 2013
Messages
5,511
Location
New Mexico, USA
Raggie has not said what wattage his solar panels are rated. When the sun goes in and out, chargers connected directly to the panels can get grumpy and uncooperative. An intermediary battery will smooth output to chargers.

Finding a safe, proper charger for raggie's bike that has a 12Volt DC input could be a challenge and a specialized expense. If he got a 12V inverter that can power some household AC devices, usefulness increases. All these elements take a hit efficiency-wise.

raggie's other thread about his bike has my suggestion that he could run panels in series to get above 42V but that is fraught with potential deadliness, given slipshod charging behavior.
 

orbital

Flashlight Enthusiast
Joined
Feb 8, 2007
Messages
4,359
Location
WI
+

Good discussion making everyone think,
but until bike battery banks have charge controllers built-in & having a voltage range for dedicated series solar hookup, it's just tricky to do.

It's very possible what I laid out, but it'll be more expensive.
 

orbital

Flashlight Enthusiast
Joined
Feb 8, 2007
Messages
4,359
Location
WI
+

... or

Having an inline solar bike controller.
Do mc4 connectors to in-line controller w/ input range from say 30~50V, converted output of 42V @ 4A max .
Then have a XT60 connector that plugs into bike. Your not having to carry the weight of controller on bike...
All super soft silicon cable.

Maybe I should invent that,, maybe I just did............and then it will be copied :unsure:
 
Last edited:

idleprocess

Flashaholic
Joined
Feb 29, 2004
Messages
7,197
Location
decamped
42V / 5V = 8.4x boost which would reduce output current to ~11.9% of input current - assuming perfect efficiency. Reality would likely be considerably less efficient because I imagine you'd need multiple stages with loss in each stage.
 

PhotonWrangler

Flashaholic
Joined
Oct 19, 2003
Messages
14,529
Location
In a handbasket
Raggie, I applaud your sense of inventiveness. Unfortunately as others have said here, the numbers don't work out in this case. It's better to keep charging it from shore power.
 

raggie33

*the raggedier*
Joined
Aug 11, 2003
Messages
13,794
Dang I wanna cross the USA if I get the courage I thought solar would be the key unless I found places to charge on my journey I have a gas bike to but it's not as realble . My panels arev5 volts USB info have one 12 volt panel but it's huge to big to carry
 

orbital

Flashlight Enthusiast
Joined
Feb 8, 2007
Messages
4,359
Location
WI
+

Solar panels are all about max surface area & are not very portable.
Cars & truck will incorporate them onto the roof & other areas,, bikes just don't have the room.

I think we all thought you were talking about doing your solar charging from home,,
on the road just won't work.

Maybe plug into a Tesla fast charge & top off your bike in about 4 seconds, :poof:!
 

PhotonWrangler

Flashaholic
Joined
Oct 19, 2003
Messages
14,529
Location
In a handbasket
It's unfortunate that solar panels are still hovering around the 20-25% efficiency range. I've read of a few claims of 40% efficiency using special materials and lenses where they're able to use additional wavelengths for photovoltaic capture, but those are still pretty exotic and prohibitively expensive.
 

BillBond

Newly Enlightened
Joined
Sep 1, 2004
Messages
72
Location
Phoenix
Raggie needs to study up on Ohm's law.
Power is a function of the voltage times the amperage, you are only talking about voltage.
Watts= Voltage x Amperage.
 

PhotonWrangler

Flashaholic
Joined
Oct 19, 2003
Messages
14,529
Location
In a handbasket
In a nutshell if you boost the voltage, you also get less current. Conversely you can transform a high voltage / low current into a low voltage with high current. This is why it's possible to plug a portable welder into a normal 15 amp household circuit and get a gazillion amps of welding power without popping the breaker.
 

KITROBASKIN

Flashlight Enthusiast
Joined
Mar 28, 2013
Messages
5,511
Location
New Mexico, USA
Not really what raggie was hoping to do, but a member on diysolarforum is looking to rig up portable solar charging for a touring ebike:


This unit is said to use Sunpower modules.

 

alpg88

Flashlight Enthusiast
Joined
Apr 19, 2005
Messages
5,395
if you go across usa on a ebike, it will take you months lol, battery charges longer than it runs. and if you use a solar and 5v to 42 booster to charge, lol, people do not live that long.

Use your gas moped. you can always keep a gas can on your luggage rack for those roads that have nothing for hundreds of miles. I had a bike with a motor like yours, probably 35 years ago, they really did not change much over those years, they are pretty reliable when installed correctly. i'd be more concerned about the bike itself than a motor.
 

Latest posts

Top