Installing a usb charger on 1993 ST1100

[karuzo]

Hi there,

I'm a relatively new owner of a 1993 ST1100, and familiar with the alternator replacement and red wire bypass. I have not checked yet if the bike has the upgraded alternator yet, nor the red wire bypass. I'll check this sometimes soon and know the 40a has slotted vents. I am curious to know if the original alternator can support a usb charger. If the original alternator can support, do you know what the maximum voltage/amp it can provide for accessory use? I recently connected a usb charger to another bike with (2) sockets that can support 5v/2.1amp each socket, seems this is the standard port capacity for charging a mobile phone.
Also, if you can share a picture of a usb port setup you have (including brand/model) and if you connected directly to the battery, or somewhere else on the bike (in my other bike I had a spare auxiliary port to connect to)?

Thanks,

Doron

 

[W0QNX]

Hard to go wrong with the cheap amazon usb things. connect to the battery and you'll have power until the battery dies. I have 2 of these and both just lay in the trunk for the phone charger and misc. that folder over the top thing is a rubber cover.

https://www.amazon.com/gp/product/B0BM3S5463/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

 

[Uncle Phil]

I use Marinco stuff for that (marine grade quality) -

Marinco Dual USB Charger & Receptacle (delcity.net)

Plenty of sellers out there for that item - that's just one.
If you don't have a fuse block on your ST to run it through, you should put an inline fuse in the circuit.

 

[jdmccright]

You likely have the smaller 28 Amp alt, but that doesn't mean it is gutless. It can handle some extra farkles, just not a lot. A USB charge port is a small draw compared to a lot of other things you can hook up like hand grip and vest heaters.

So go ahead and put in a charger plug. I myself installed two 12V socket plugs into the LH pocket, then add a USB plug-in adapter. Just beware that if you connect it direct to battery (not key-on), and it has power lights it will eventually draw down the battery. You might add a switch to turn it on/off as well.

 

[karuzo]

You likely have the smaller 28 Amp alt, but that doesn't mean it is gutless. It can handle some extra farkles, just not a lot. A USB charge port is a small draw compared to a lot of other things you can hook up like hand grip and vest heaters.

So go ahead and put in a charger plug. I myself installed two 12V socket plugs into the LH pocket, then add a USB plug-in adapter. Just beware that if you connect it direct to battery (not key-on), and it has power lights it will eventually draw down the battery. You might add a switch to turn it on/off as well.

Thanks for clarifying -I was aware of the benefit of on/off switch if you connect directly to the battery. I was looking now, and see there are usb chargers that can connect to the battery tender port, which I might consider, assuming no concern with that. I saw one with voltmeter display. Curious to know what the minimum voltage it should display while riding the bike, and have (2) 5V devices connected to it be? Sorry for asking this, as I'm new to electrical.
Thanks.

 

[karuzo]

Hard to go wrong with the cheap amazon usb things. connect to the battery and you'll have power until the battery dies. I have 2 of these and both just lay in the trunk for the phone charger and misc. that folder over the top thing is a rubber cover.

https://www.amazon.com/gp/product/B0BM3S5463/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

Thanks for recommending WØQNX.

 

[karuzo]

I use Marinco stuff for that (marine grade quality) -

Marinco Dual USB Charger & Receptacle (delcity.net)

Plenty of sellers out there for that item - that's just one.
If you don't have a fuse block on your ST to run it through, you should put an inline fuse in the circuit.

Thank you for the recommendation Uncle Phil.

 

[jdmccright]

My bike is newer with the 40-Amp alt, so I cannot really say. But when running, your alt should be providing 14.1-14.2 Volts. Even if you were pulling max amps from both USB ports (5V at 2.1Amps each) that would barely register as it's just 0.9 A at 12V. It would dip to maybe 13.6-13.7 Volts theoretical (napkin calcs involved, please don't judge).

 

[karuzo]

My bike is newer with the 40-Amp alt, so I cannot really say. But when running, your alt should be providing 14.1-14.2 Volts. Even if you were pulling max amps from both USB ports (5V at 2.1Amps each) that would barely register as it's just 0.9 A at 12V. It would dip to maybe 13.6-13.7 Volts theoretical (napkin calcs involved, please don't judge).

Thanks for clarifying that.

 

[Larry Fine]

Switching to LED lighting would give you plenty of extra capacity; even just the headlight bulbs.

 

[Willsmotorcycle]

I don’t know why these links are so long… anyway if you go with and SAE connector you can add other things if you need them.

Amazon.com

Amazon.com

 

[karuzo]

Switching to LED lighting would give you plenty of extra capacity; even just the headlight bulbs.

That’s a good point.

 

[ST1100Gold]

I fitted one into the right side fairing panel - bought off e-bay for under £10, wired into main line (ignition has to be on to power up), bonus is it has a voltage readout and two USBs

 

[karuzo]

I fitted one into the right side fairing panel - bought off e-bay for under £10, wired into main line (ignition has to be on to power up), bonus is it has a voltage readout and two USBs

Thanks for sharing photos.

 

[klaproth]

I am SURE you know this already, but leaving a USB charger hooked up ( hot) to a battery is a good way to kill an otherwise good battery. Even with nothing plugged into it, it draws a small current, and WILL eventually kill the battery.
On my other bike, ( NC700X), the PO had installed a USB charger, direct to the battery. Just before I bought it, he had to replace a 2 month old battery with a new one. I suspect that he sold the bike cheaply because he thought the alternator or rectifier/wiring was bad. I caught it when I was going over the bike , changing fluids, adjusting stuff, etc.
Words to the wise......

 

[karuzo]

I am SURE you know this already, but leaving a USB charger hooked up ( hot) to a battery is a good way to kill an otherwise good battery. Even with nothing plugged into it, it draws a small current, and WILL eventually kill the battery.
On my other bike, ( NC700X), the PO had installed a USB charger, direct to the battery. Just before I bought it, he had to replace a 2 month old battery with a new one. I suspect that he sold the bike cheaply because he thought the alternator or rectifier/wiring was bad. I caught it when I was going over the bike , changing fluids, adjusting stuff, etc.
Words to the wise......

Thanks, yes, I’m aware of that.

 

[jfheath]

I am SURE you know this already, but leaving a USB charger hooked up ( hot) to a battery is a good way to kill an otherwise good battery. Even with nothing plugged into it, it draws a small current, and WILL eventually kill the battery.

One way is to connect direct to the battery via a relay which is triggered by something that turns on (and off) with ignition. This saves any extra load on the wiring and shuts off your circuits whenever the power goes.

How much is a small current. 0.5A from a 12Ah battery will flatten the battery in a day. 0.1A will take 5 days, but it will become useless for starting the motor long before that. That is too much in my not very electrically aware opinion !!

 

[ST Gui]

I am SURE you know this already, but leaving a USB charger hooked up ( hot) to a battery is a good way to kill an otherwise good battery. Even with nothing plugged into it, it draws a small current, and WILL eventually kill the battery.

I was just going to post similarly. A USB charger plug with or without a power indicator (LED) has a parasitic draw. I left one in the socket and it drained my car battery enough that the solenoid chattered. (I don't drive it all that much.)

 

[karuzo]

I was just going to post similarly. A USB charger plug with or without a power indicator (LED) has a parasitic draw. I left one in the socket and it drained my car battery enough that the solenoid chattered. (I don't drive it all that much.)

I assume this won’t be the case when there is an on/off switch on the usb charger?

 

[ST Gui]

I assume this won’t be the case when there is an on/off switch on the usb charger?

I can't speak to that other than to say you're probably correct. It wouldn't make a lot of sense to control only the power to a device from the socket and not control power to the socket instead.

My US car sockets are always live. Some/most/all Japanese cars' sockets aren't live with the key off. That may apply to other cars of "foreign" manufacture.