How to run 12 volt accessories from your Rad

[Altema]

I was glad that the Rad display has a USB port. However, its usefulness is limited by the output level, which is 0.9 amps. This is enough to charge most phones, but some accessories require more. My headlight and my heated vest require 3 amps to charge, meaning that they cannot be charged at all by the port on the bike. Upgrading the display and controller made it worse, as the new display only outputs 0.4 amp at 4.8 volts.

I was unable to find USB chargers or ports that worked on a 48 volt input. So, I ordered a waterproof 48 to 12 volt converter, and made a connector that will let me plug it into either battery, or plug into both batteries and act as a bridge. The connector is basically a male and a female XT90 connector soldered back to back, with the leads for the convertor soldered in. That handled the 48 volt side, and the convertor cannot be plugged in wrong. For the 12 volt output, I chose Anderson power pole connectors to make sure they never get plugged into the 48 volt system. You can plug any 12 volt load in here, but I went with a 12 volt automotive socket to be used with a double USB A charger with 3 amp output on both sockets. As a bonus, I can also plug in a 12 volt to 110 volt AC power invertor, as long as it's a small one. I foolishly went for the 10 amp convertor instead of the 20 amp version, which would have allowed for 240 watts of AC power.

Photos are below, and although I conveniently placed the convertor and socket in my rear rack bag (it works there with or without the rear battery), the convertor can be mounted under the rack or under the crank, since it is waterproof. The 48 volt source will need to come from the battery connectors on the battery mounting plate, and any splices done on the too-short convertor will need to be sealed (silicone plus heat shrink tubing), but it will mean you can run all kinds of automotive and motor cycle goodies, including lighting systems. Just putting this out there in case someone finds it useful!

[specelec]

Nice mod! Now you just need folding solar panels and an MPPT charge controller setup so you can ride forever!

[Altema]

Nice mod! Now you just need folding solar panels and an MPPT charge controller setup so you can ride forever!

Lol, that would be nice. I did think about designing a bike trailer where the top folded out into a three panel solar array, but that would be more useful while camping. Until then, 80 miles of range is enough!

[fin_rad]

Thanks for sharing this, clear and simple. So far I am using a power bank for any 5V-12V devices, since I don't want to mess up with my bike while under warranty time. But after that this will be on my to-do list.

[Veggyhed]

Very nice. Do you have links to the hardware you purchased?

Sent from my Pixel 3a using Tapatalk

[Altema]

Yes!

The 48 to 12 volt converter is below. If you plan on running larger accessories, like big lights or a power inverter, I'd recommend the 20 amp version versus the 10 amp version I ordered.
https://amzn.to/2YDyahC

Next is the 12 volt socket for automotive-type accessories. It had really nice terminals on it, so cut them off and saved them since I was using Anderson power pole connectors on the 12 volt side.
https://amzn.to/2Yy70Zx

Next up is the dual USB port charger. I chose this one specifically because it puts out 3 amps @ 5 volts, which not many of them do. 3 amps is required to charge my Nitecore headlight, and the second port can charge the power bank for my heated vest. Additionally, in an emergency, the 3 amp output can also power my vest directly with an extension cable. Please not that 3 amps is unrelated to QuickCharge version 3, with is a charge control protocol.
https://amzn.to/2QiJ77t

Below is the link to the afore mentioned Anderson power pole connectors. These need a special crimper, or you can snip the crimping lugs down to make them shorter, and crimp them with pliers. I took the additional step of soldering them. To make sure I never have a wrong connection, I use these on the 12 volt connections. You could also use regular insulated spade connectors, or XT60 connectors, but some aftermarket battery chargers like the one from Luna Cycle also use the XT60, so I avoided them.
https://amzn.to/3asMMWT

The XT90 connectors were used on the 48 volt connections, and those are linked below, but you may be able to find smaller quantities. Note that these require a heavy duty soldering gun. Most soldering pencils will not work.
https://amzn.to/36xZZwm

And lastly, I purchased a low wattage power inverter to charge my heated gloves, which only work with a 110 volt AC adapter. It works well, and I was able to charge both of my glove batteries from the bike alone, and it used less than 0.1% of a volt from the bike battery. The only thing I don't like is that the fan is constant instead of only coming on when needed, but at least it's quiet.
https://amzn.to/3tjjRx6

Let me know if you have questions!

[Veggyhed]

Thank you so much. My imagination is running wild right now. I thought this would have come to a lot more in total cost.
I commute at night and early hours of the morning. It's getting pretty cold here and my hands are struggling a little when it drops below 20 f. So I was looking for heated gloves and a way to power and charge them. It appears I have an answer now , [emoji16]

Sent from my Pixel 3a using Tapatalk

[wojtek-in-seattle]

Altema, great ideas. Thanks for sharing. fin_rad, I also don't want to mess with connections to battery while bike under warranty. Power bank idea sounds interesting. Any recommendations on a product? Preferably waterproof?

[Altema]

Altema, great ideas. Thanks for sharing. fin_rad, I also don't want to mess with connections to battery while bike under warranty. Power bank idea sounds interesting. Any recommendations on a product? Preferably waterproof?

I understand not wanting to change wiring while under warranty, so a power bank is a good option.
We've had about twenty of them (used to test them as a hobby), but only two of them were water resistant.
I guess the best place to start is asking a few questions:

What you are going to power with it?
How many devices need to be charged at the same time?
Will you be able to recharge at your destination?
Since it's easier if your phone cable fits your power bank, what type of phone charger do you have?

[wojtek-in-seattle]

I understand not wanting to change wiring while under warranty, so a power bank is a good option.
We've had about twenty of them (used to test them as a hobby), but only two of them were water resistant.
I guess the best place to start is asking a few questions:

1. What you are going to power with it?
2. How many devices need to be charged at the same time?
3. Will you be able to recharge at your destination?
4. Since it's easier if your phone cable fits your power bank, what type of phone charger do you have?

1. I'm hoping to power LED lights to improve visibility.
2. (4) strips of LED lights at maximum. (2) in front and (2) in the rear.
3. Mine are short commuter roundtrips. Charge back at home.
4. Phone has USB-C connection, but no need to charge phone from the power bank (see #3).

Any advice on power banks is much appreciated. Thank you.

[Altema]

I understand not wanting to change wiring while under warranty, so a power bank is a good option.
We've had about twenty of them (used to test them as a hobby), but only two of them were water resistant.
I guess the best place to start is asking a few questions:

1. What you are going to power with it?
2. How many devices need to be charged at the same time?
3. Will you be able to recharge at your destination?
4. Since it's easier if your phone cable fits your power bank, what type of phone charger do you have?

1. I'm hoping to power LED lights to improve visibility.
2. (4) strips of LED lights at maximum. (2) in front and (2) in the rear.
3. Mine are short commuter roundtrips. Charge back at home.
4. Phone has USB-C connection, but no need to charge phone from the power bank (see #3).

Any advice on power banks is much appreciated. Thank you.

I see they do have USB 5 volt LED strips, so a good power bank will be fine. If you are running four strips, you will need four USB A ports.
A slim one is here with four ports, but recharges using Micro USB and Lightning.
https://amzn.to/2MckPKV

Here's another, but this one has only micro USB input for charging.
https://amzn.to/3akmbLF

I have not used either one of these models, but if you want to look for more, just search "4 port power bank".
I have a good one myself, but the design has been changed and it no longer has four USB A type ports.

[Whyme]

Just an idea if you have a rack, front or back . Buy lithium motorcycle battery like I have on my motor cycle.
Run your extra 12 volt accessories off of it.

[Buzz]

Hi, I'm new to rad wagon, but your idea for a 12V power supply is great!
I'm living in Europe and searching for this connector. Maybe someone knows where to buy it?
Or the right manufacturer to google for?
BR Buzz

[Altema]

Hi, I'm new to rad wagon, but your idea for a 12V power supply is great!
I'm living in Europe and searching for this connector. Maybe someone knows where to buy it?
Or the right manufacturer to google for?
BR Buzz

Is that the two-pin power connector from the battery to the controller?
If so, you can buy the battery side from Bolton Ebikes in the US. They make them to plug aftermarket batteries into the controller.

[bornslyasafox]

Finding this thread in 2024 has been an absolute blessing.