Shimano Steps charger connector pinout

[Standroid]

Can anyone please offer some insight into the pinout and function of the five wires in the Shimano Steps charger-to-battery connector?

My Shimano supplied charger is all I need WHEN I'm connected to AC mains power. However, I'm often away from AC mains for days or even weeks at a time. At those times I have a supply of 12vdc power and I would like to be able to charge my Shimano Steps battery without the inefficiencies of using an AC inverter.

I have a nice DC-DC converter with adjustable, regulated 35-50 vdc output and adjustable current limiting that should be just the ticket - two wires in from my 12vdc source and two wires out to charge the Shimano battery. But, the Shimano charging connector has five pins, not two!

Two of the five pins are larger and clearly carry the charging current. The other three are likely to be communication between the battery and charger, but what do they communicate? And more to the point, what logic levels do I need to apply to those pins when charging the battery?

Finally, while my fallback is to chop the Shimano charging cable, and reconnect it with generic industrial connectors to either the Shimano charger or my own charger, I would much prefer to leave the Shimano charger intact and install a compatible connector on my charger. Can anyone point me to a source of that five-pin connector that Shimano uses?

Many thanks,

Stan

 

[cyclebuddy]

I don't know the Shimano Steps system specifically (maybe somebody else here does), but on some other five-pin charger connections, two of the three extra pins carry overheat and overcharge cut-off signal for extra safety, and the third extra pin is handshaking - deliberately designed to stop you from using any third-party charging method. My own 5-pin charger has an extra chip to check those functions and cannot be bypassed (that I can see) - so I have to use an Inverter when mobile.

 

[Standroid]

I don't know the Shimano Steps system specifically (maybe somebody else here does), but... and the third extra pin is handshaking - deliberately designed to stop you from using any third-party charging method... so I have to use an Inverter when mobile.

Interesting... and ugly! By "handshaking" I don't suppose you mean just presenting a constant logic level? No, probably more like a multistep sequence. So how clean does an inverter typically have to be for these chargers? Pure sine wave? And how much headroom did you provide on inverter output power rating vs charger input spec?

 

[cyclebuddy]

I don't know. It wasn't worth the time, effort, or cost of investigating/developing a direct charging method since a 20% overall conversion loss wasn't (to me) worth the cost of my time needed to work out how to do it. From watts consumed, my own e-bike charger runs a self-check routine (about 20w over 5 seconds) before applying max current to an empty pack. As my 42v/2A charger uses 80-90w maximum, I use either a 400w square wave and/or a 300w simulated sine inverter to charge - both limited to a 10 amp 12v supply from the vehicle cigarette socket for convenience - and both work equally well.