Thunder Box USB charger

[Swell]

I'm trying to find a solution to my power problems which are, I need more charging capacity when touring. I want a four bank USB charger in my tank bag but, can't wire this direct to the battery as the amps will be too high (I believe?). I've been looking at the Thunder Box USB charger which will allow me to either plug a four bank into it or, remove the single it comes with and replace it with a four. The brief on Motorworks says it can be wired in via a switched live with a 2 amp fuse (inline I assume?) but, it's prepared for use with the TB1. I don't need any additional gadgets added to the system, only charging so feel the cost of a TB1 as well would be a waste and, I really don't want loads of wires running from under the seat up to the cockpit so, I'd prefer the USB charger connected direct via a switched live which will depower when the ignition is off. My question is, where is the best switched live for me to tap into. I've seen the YouTube vid of the bloke fitting a camera and the Posi Tap looks a great way to connect it but, is that fuse the best location?

Thanks.

 

[Bigcats]

I'm trying to find a solution to my power problems which are, I need more charging capacity when touring. I want a four bank USB charger in my tank bag but, can't wire this direct to the battery as the amps will be too high (I believe?). I've been looking at the Thunder Box USB charger which will allow me to either plug a four bank into it or, remove the single it comes with and replace it with a four. The brief on Motorworks says it can be wired in via a switched live with a 2 amp fuse (inline I assume?) but, it's prepared for use with the TB1. I don't need any additional gadgets added to the system, only charging so feel the cost of a TB1 as well would be a waste and, I really don't want loads of wires running from under the seat up to the cockpit so, I'd prefer the USB charger connected direct via a switched live which will depower when the ignition is off. My question is, where is the best switched live for me to tap into. I've seen the YouTube vid of the bloke fitting a camera and the Posi Tap looks a great way to connect it but, is that fuse the best location?

Thanks.

Under the seat is a place and is used by the guys over at The Bike Thing...he even has a video which will guide you

This is where I also tapped it for a switch live and no issues. The video starts where he points out where you can tap into.

 

[Bigcats]

Also one of the lads found this device which is basically the same as a Thunderbox but cheaper

Though by the looks of it each output is limited to 5 amp which may not help with 4 USB devices charging but worth a look

Thread 'Oxford version of Fuseblock'

Feb 7, 2025

By and large I like Oxford bike products, they are generally fit for purpose and cost less than ‘big brand’ name kit. I have a Fuseblock fitted to one of my bikes and was looking for a similar solution for the other bike when I came across this :

Oxford Junction Box -12V with fused power outlets : Oxford Products

Oxford Products Ltd (OXFORD) - a global leader in motorcycle and bicycle products. Established in 1973, OXFORD is now one of the world's leading suppliers of products to the two-wheeled industry.

www.oxfordproducts.com

Has anyone here used one and care to comment on them please ?

• KMD
• Replies: 22
• Forum: GS Mods

• 

 

[Swell]

Under the seat is a place and is used by the guys over at The Bike Thing...he even has a video which will guide you

This is where I also tapped it for a switch live and no issues. The video starts where he points out where you can tap into.

This was the video I was refering to in my post. Very informative and I'll have a look at the area under my seat when I get home (out of town for another week). I have a GSA and that's GS, not sure if the layout will differ.
Cheers

 

[Bigcats]

This was the video I was refering to in my post. Very informative and I'll have a look at the area under my seat when I get home (out of town for another week). I have a GSA and that's GS, not sure if the layout will differ.
Cheers

No it will be the same

 

[Victor c]

I’ve refrained from using the 7 amp fused wire under the riders seat on my current bike, as I’ve had issues with the left handlebar switch cluster (fed by this wire). Instead, I’ve used this Denali adaptor that links into the oem sat nav wiring harness https://www.sportsbikeshop.co.uk/motorcycle_parts/content_prod/2409932

Edit - I believe this is how A Bike Thing now source the switched live as well.

 

[Swell]

Also one of the lads found this device which is basically the same as a Thunderbox but cheaper

Though by the looks of it each output is limited to 5 amp which may not help with 4 USB devices charging but worth a look

Thread 'Oxford version of Fuseblock'

Feb 7, 2025

By and large I like Oxford bike products, they are generally fit for purpose and cost less than ‘big brand’ name kit. I have a Fuseblock fitted to one of my bikes and was looking for a similar solution for the other bike when I came across this :

Oxford Junction Box -12V with fused power outlets : Oxford Products

Oxford Products Ltd (OXFORD) - a global leader in motorcycle and bicycle products. Established in 1973, OXFORD is now one of the world's leading suppliers of products to the two-wheeled industry.

www.oxfordproducts.com

Has anyone here used one and care to comment on them please ?

• KMD
• Replies: 22
• Forum: GS Mods

• 

The Oxford looks like an option, however, I don't know how it can be shut off without being on a switched live circuit, connecting directly the battery will ensure it's constantly producing output? The TB USB is the same price so no loss/gain there.
Thanks again

 

[wilbjr21]

One thing worth remembering when amps are being discussed ..........

USB output is 5V; so if it delivers 4A that is 20 W being consumed.

The supply to this is 12V; 20W from the 12V supply is 1.7A - so not too bad.

Just saying

 

[Bigcats]

The Oxford looks like an option, however, I don't know how it can be shut off without being on a switched live circuit, connecting directly the battery will ensure it's constantly producing output? The TB USB is the same price so no loss/gain there.
Thanks again

Correct it cannot

I assure you doing the switch live will make sure your battery is protected

the Thunderbox is only 2 amp though so if you plug in 4 devices they will take forever to charge where as having a switch live box like the Oxford or the TBU01/02 will get you more power per usb device

 

[Swell]

I’ve refrained from using the 7 amp fused wire under the riders seat on my current bike, as I’ve had issues with the left handlebar switch cluster (fed by this wire). Instead, I’ve used this Denali adaptor that links into the oem sat nav wiring harness https://www.sportsbikeshop.co.uk/motorcycle_parts/content_prod/2409932

Edit - I believe this is how A Bike Thing now source the switched live as well.

I've used one of the below in the past when I wasn't using GPS but, I've changed bikes and bought a Nav 6 so that outlet is taken. I'd prefer to use the GPS switched live as it's routing is inline with the tank bag so may need less wire to achieve the required result.

Power cable BMW CAN BUS, universal

New ideas for your motorbike: German company Touratech is home of high-quality innovative products for traveling, outdoor and sports activities with motorcycles.

www.touratech.com

Cheers

 

[Swell]

One thing worth remembering when amps are being discussed ..........

USB output is 5V; so if it delivers 4A that is 20 W being consumed.

The supply to this is 12V; 20W from the 12V supply is 1.7A - so not too bad.

Just saying

Sorry Wil, I missed your point there. A GSA alternator will pump out 600W at 12v which is 50amps, more than enough to charge all my bits and bobs.

 

[er-minio]

Yes, but you're probably not getting 50amp from the switched live you might be tapping in. Unless it's a really thick cable

Also, check which devices you'll be charging when doing all the calculations. Some will need more than 20W and most of these might need some specific USB sockets that will do an "handshake" in order to agree to deliver more power.
In all fairness, most powerbricks have those sockets. Like the Anker ones, etc.

 

[Swell]

I've used one of the below in the past when I wasn't using GPS but, I've changed bikes and bought a Nav 6 so that outlet is taken. I'd prefer to use the GPS switched live as it's routing is inline with the tank bag so may need less wire to achieve the required result.

Power cable BMW CAN BUS, universal

New ideas for your motorbike: German company Touratech is home of high-quality innovative products for traveling, outdoor and sports activities with motorcycles.

www.touratech.com

Cheers

just found this on Nippy's site:

Installation Note: The DENALI switched power adapter is intended to trigger a relay (sold separately) and is not intended to directly power an electrical accessory. Powering accessories directly from this adapter could overload the circuit and trigger the CanBus to cut power to the circuit until the overload is removed.

 

[Swell]

Yes, but you're probably not getting 50amp from the switched live you might be tapping in. Unless it's a really thick cable

Also, check which devices you'll be charging. Some will need more than 20W and most of these might need some specific USB sockets that will do an "handshake" in order to agree to deliver more power.
In all fairness, most powerbricks have those sockets. Like the Anker ones, etc.

GoPro battery charger, iPad mini, power bank and NOCO if discharged. These won't all require charging at the same time but, I'd like the option. The GSA has another power outlet on the left side which I may look to utilise which I believe is also switched live?

 

[er-minio]

I have an older GSA so cannot be sure about the newer model. The existing sockets should provide around 5A. But I'm pretty sure someone else can be more precise.

These won't all require charging at the same time but, I'd like the option.

I understand.
To be fair, if they do get less amperage/wattage, they just charge slowly. No big issue. If the devices are not running it's not a problem.

GoPro doesn't draw much usually.
When traveling I don't really use power from the bike apart from the GPS, and keep GoPro batteries/GoPro and my iPhone topped up via a powerbank in my backpack that I then charge at night. It goes on all day.

You might be able to tap into the battery directly. Maybe easier.

 

[Swell]

Correct it cannot

I assure you doing the switch live will make sure your battery is protected

the Thunderbox is only 2 amp though so if you plug in 4 devices they will take forever to charge where as having a switch live box like the Oxford or the TBU01/02 will get you more power per usb device

Thanks Bigcats. The only issue with that is, I'd require multiple single USB outlets running into the tank bag, spaghetti/birds nest protentional = high.
I used to use a Optimate double USB that plugged into the RH outlet but, they've changed the socket to USB A so that can only be used on the auxiliary/trickle charge outlet on the LHS. This will keep my mind active for a while.

Cheers

 

[Swell]

I have an older GSA so cannot be sure about the newer model. The existing sockets should provide around 5A. But I'm pretty sure someone else can be more precise.



I understand.
To be fair, if they do get less amperage/wattage, they just charge slowly. No big issue. If the devices are not running it's not a problem.

GoPro doesn't draw much usually.
When traveling I don't really use power from the bike apart from the GPS, and keep GoPro batteries/GoPro and my iPhone topped up via a powerbank in my backpack that I then charge at night. It goes on all day.

You might be able to tap into the battery directly. Maybe easier.

I've given that some thought but, I'm shit scared of the switched live issue. I can be a bit of a scatter brain at times and would doubtless wake to a dead battery after leaving shit plugged in all night.

 

[Bigcats]

I've given that some thought but, I'm shit scared of the switched live issue. I can be a bit of a scatter brain at times and would doubtless wake to a dead battery after leaving shit plugged in all night.

What is your concern with switched live??

It works!! and takes literally 2 seconds to connect...you're not cutting any wires, just tapping in. You don't need to do anything

You can use one of these to make it even simpler

Amazon.co.uk

 

[wilbjr21]

Sorry Wil, I missed your point there. A GSA alternator will pump out 600W at 12v which is 50amps, more than enough to charge all my bits and bobs.

My point was as er-minto and Bigcats have said - better than me.

It's good to do some sums.

 

[er-minio]

What is your concern with switched live??

I think he meant the opposite: he doesn't want to tap into the battery and wants to be sure the feed is off when the bike's ignition is off. That is agreeable