Repurpose RAD battery as emergency power source

[eCouleeRider]

Hi! Checked the forums but have not found definitive answers.

Is it possible to repurpose a standard Rad 48v battery as an emergency power source? Think here of charging a phone or powering a small device.
If so, how? Details appreciated.
Has anyone done this?

Thanks!

 

[Ccount]

You would need an inverter with a 48v input, but yes, it would work just fine. Remember though that you would be very limited to the number of amps available (about 6 A max at 120v)

 

[Explorer-1]

I've seen some devices that specifically target the use of bike batteries. I think it was probable on eBay. are you wanting to power 12VDC, 5VDC? Essentially you can look for a buck converter with suitable input, output, and power ratings for your application If you want to power lower voltage DV devices. You can use them in combination with an inverter to power AC devices (110/`120 VAC), or a separate Boost Converter and an inverter.

You could get a Buck/Boost converter and make a variable power-supply with a good range.

What voltage are you looking for?

 

[Ccount]

Also, the Bolton (and other) displays have a USB port on it, which is more than adequate to charge a cell phone right on your bike! I do it every ride!

 

[legsofbeer]

The stock radpower controller on most of their bikes has a 0.5 amp USB A port underneath the display. Get yourself a small USB battery brick so you can charge that when you're not charging devices directly. And, of course, you can use the bike itself as an emergency light in a power outage. I'd bet the battery could drive the front light for at least a week.

 

[Tars Tarkas]

Search Google or Amazon for 48v to 12v converter. You'll have to find some connectors and/or do some soldering but you'd end up with something you could attach a cigarette lighter kind of receptacle to. Then you could plug in a USB charger or any other 12v-powered device. It would really be pretty easy. I'll let someone else do the Ohm's Law math on how long the battery would last, depending on what you plug into it.

One other potentially big consideration is that using the battery that way would put more charging cycles on it, and more wear and tear in general, thereby lowering its life expectancy. Something to think about at $550 replacement cost, But for emergencies , yeah, sure. It would be a pretty good little thing to make and market as an out of the box solution.

TT

 

[6zfshdb]

Hi! Checked the forums but have not found definitive answers.

Is it possible to repurpose a standard Rad 48v battery as an emergency power source? Think here of charging a phone or powering a small device.
If so, how? Details appreciated.
Has anyone done this?

Thanks!

I built this rig mainly to discharge my batteries for storage but it can also be used as a portable light source outdoors or inside during a power failure:




My batteries use a slot type connector which was easy to tap by cutting a cheap extension cord plug in half:


You would likely have to use a different method for your Rad battery though. My batteries have a built in switch & fuse. Keep in mind these would have to be added for batteries that don't have them.


When not in use, the rig hangs on a wall above the work bench:




To use household appliances, it would be a simple matter to wire up a 48V DC to 110V AC inverter such as this one:

Majorsine1000-48-2U DC-AC Inverter | Majorpower

Majorsine1000-48-2U, DC to AC power inverter, 48VDC to 120VAC, 1000VA and 800W, 2U rackmount.

www.majorpower.com

To charge electronic devices, you could also wire up this 48V DC to USB converter:

Amazon.com: SMAKN 12V 24V 36V 48V (8-50V) to 5V 3A 15W DC/DC Buck Power Converter Voltage Step Dowm Power Supply MICRO-USB output Waterproof : Electronics

Buy SMAKN 12V 24V 36V 48V (8-50V) to 5V 3A 15W DC/DC Buck Power Converter Voltage Step Dowm Power Supply MICRO-USB output Waterproof: Power Converters - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

 

[eCouleeRider]

Wow! Thank you for all the great replies! This addresses my two main concerns: battery maintenance in the winter and using the battery in an emergency. I am using a Luna charger, so I am able to charge at low amps to a desired level - that should help with "winter maintenance" charging.

Now my only question would be: how to make the actual physical connection with a Rad battery? Is there an off-the shelf component that will fit, and what would positive and negative leads be? I built the plug for the Luna based on a good YouTube video, so that is something I am comfortable with. Is there is a reference I should be looking at, or specific tool I should have in hand?

Thanks!

Report

 

[Ccount]

Wow! Thank you for all the great replies! This addresses my two main concerns: battery maintenance in the winter and using the battery in an emergency. I am using a Luna charger, so I am able to charge at low amps to a desired level - that should help with "winter maintenance" charging.

Now my only question would be: how to make the actual physical connection with a Rad battery? Is there an off-the shelf component that will fit, and what would positive and negative leads be? I built the plug for the Luna based on a good YouTube video, so that is something I am comfortable with. Is there is a reference I should be looking at, or specific tool I should have in hand?

Thanks!
Report

Super simple! Simply purchase one of these on Amazon for a buck (or better yet buy the package), and plug right into the charging port on the battery. I use the port to power some super high intensity LED lights for my night rides on the beach and golf course.

https://www.amazon.com/gp/product/B07CWQPPTW/ref=ox_sc_act_title_1?smid=A1P8HQHD4AJMLY&psc=1

 

[6zfshdb]

This was posted in another thread by member Kyogero:

Rad Power Bikes Battery Adapters | Big Game Bikes

Easily connect and use any suitable battery you wish with this simple Rad Power Bikes adapter. Various RAD power bikes adapters options available.

biggamebikes.com

You might find a connector that will fit. The vendor is in the UK though so shipping could be a problem.

 

[eCouleeRider]

Super simple! Simply purchase one of these on Amazon for a buck (or better yet buy the package), and plug right into the charging port on the battery. I use the port to power some super high intensity LED lights for my night rides on the beach and golf course.

https://www.amazon.com/gp/product/B07CWQPPTW/ref=ox_sc_act_title_1?smid=A1P8HQHD4AJMLY&psc=1

So I can draw current back through the charging port? I already built those connectors for charging with the Luna.

Here I was thinking that I had to connect to the leads on the bottom of the battery. Would I still need the 48v to 12v converter - or something else to regulate the rate of discharge? I am thinking here that there may be circuitry or fusing that is on the discharge side and not on the charging side. (BTW - any corrections of how I am thinking about this are welcome!)

 

[6zfshdb]

Super simple! Simply purchase one of these on Amazon for a buck (or better yet buy the package), and plug right into the charging port on the battery. I use the port to power some super high intensity LED lights for my night rides on the beach and golf course.

https://www.amazon.com/gp/product/B07CWQPPTW/ref=ox_sc_act_title_1?smid=A1P8HQHD4AJMLY&psc=1

You have to be careful discharging via the battery charging port. The internal wiring likely involves the BMS and could easily be overloaded if you draw too much current.

 

[eCouleeRider]

You have to be careful discharging via the battery charging port. The internal wiring likely involves the BMS and could easily be overloaded if you draw too much current.

Thanks. That was my concern.

Is the BMS in a Rad battery in the battery itself, or in the controller?

 

[eCouleeRider]

I built this rig mainly to discharge my batteries for storage but it can also be used as a portable light source outdoors or inside during a power failure:

View attachment 73113 View attachment 73110


My batteries use a slot type connector which was easy to tap by cutting a cheap extension cord plug in half:

View attachment 73115 View attachment 73111 View attachment 73112
You would likely have to use a different method for your Rad battery though. My batteries have a built in switch & fuse. Keep in mind these would have to be added for batteries that don't have them.


When not in use, the rig hangs on a wall above the work bench:

View attachment 73114


To use household appliances, it would be a simple matter to wire up a 48V DC to 110V AC inverter such as this one:

View attachment 73116

Majorsine1000-48-2U DC-AC Inverter | Majorpower

Majorsine1000-48-2U, DC to AC power inverter, 48VDC to 120VAC, 1000VA and 800W, 2U rackmount.

www.majorpower.com

To charge electronic devices, you could also wire up this 48V DC to USB converter:

View attachment 73117

Amazon.com: SMAKN 12V 24V 36V 48V (8-50V) to 5V 3A 15W DC/DC Buck Power Converter Voltage Step Dowm Power Supply MICRO-USB output Waterproof : Electronics

Buy SMAKN 12V 24V 36V 48V (8-50V) to 5V 3A 15W DC/DC Buck Power Converter Voltage Step Dowm Power Supply MICRO-USB output Waterproof: Power Converters - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

This is quite awesome!

 

[eCouleeRider]

I've seen some devices that specifically target the use of bike batteries. I think it was probable on eBay. are you wanting to power 12VDC, 5VDC? Essentially you can look for a buck converter with suitable input, output, and power ratings for your application If you want to power lower voltage DV devices. You can use them in combination with an inverter to power AC devices (110/`120 VAC), or a separate Boost Converter and an inverter.

You could get a Buck/Boost converter and make a variable power-supply with a good range.

What voltage are you looking for?

I am thinking 12 vdc

 

[eCouleeRider]

The stock radpower controller on most of their bikes has a 0.5 amp USB A port underneath the display. Get yourself a small USB battery brick so you can charge that when you're not charging devices directly. And, of course, you can use the bike itself as an emergency light in a power outage. I'd bet the battery could drive the front light for at least a week.

Thanks. I thought about the USB A port too - would like to make something like that which sits right on the battery itself.

 

[eCouleeRider]

I think what I am looking for is called a discharge connector - one specific to the Rad battery. Would be willing to build my own if I could find the correct components!

 

[legsofbeer]

Is the BMS in a Rad battery in the battery itself, or in the controller?

I believe it is in the battery itself, I don't see how it could do cell pack balancing otherwise. FWIW, after installing an aftermarket controller there were no config parameters oriented to the battery, besides the low voltage shutoff (I use 40v) which kills power to the motor but still leaves the lights and controller powered. So I will bet that if I set the controller voltage shutoff to some silly low value (eg 36volts), the battery's BMS would shut things down before reaching that low voltage. Not going to test that though, want to milk this battery for as much useful life as I can get. When the BMS does shut down the battery that battery stays off until charged for a while. Only did that once just to see what would happen.

There are two fuses in the battery, a 40amp and 5 amp; I assume the 40amp is for discharge through the main terminals, and the 5 amp for charging via the barrel plug. I didn't know of the pulling power via charging port trick, I'd be careful about drawing more than 2 amps from that.

 

[legsofbeer]

I thought about the USB A port too

Someone on another thread was saying they may have fried the display's USB port by drawing too much current using a USB splitter. If so, I'm disappointed that the display is vulnerable to overdraw.

 

[BKing]

How low are some of you discharging your battery for storage? I hope no more than half and do so at a fairly slow rate. Also, loading the charge port is asking for a bad BMS.