Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[SnakeeH]

Hello,
I am looking for a solution to the following question: on my Zero FXS I have the usual high voltage battery completed with a 12V plug connected to several functions (lights, USB...). When the bike is off, everything is thus shut down. I would like to find a way to keep this 12V plug alive when the engine is off, whether by connecting it differently or adding a external smaller battery. Did someone try these ideas already? Could you advise? Thanks!
Cheers
Hugues

[pacificcricket]

Something like this should work :
https://www.ebay.com/itm/TalentCell-12V-Lithium-ion-Battery-PB120B1-Rechargeable-38400mAh-142-08Wh-Li-io-/273643129229

[Crissa]

How would you wire this up to charge while the bike was charging?

-Crissa

[pacificcricket]

I think it's not necessary to charge it while the bike is charging, given how little capacity the whole thing has in comparison to the traction battery pack. I would just wire 12v dc-dc out to its input, so it would charge when the bike is being used.

[Curt]

It might be interesting to add another small DC-DC converter. MEPOS has some interesting things. I don't know where to order them, how much they cost, their parasitic drain and load requirements, etc. There are models that take 72-144V input and produce 10W, 15W, 35W, or 50W output, and they're quite small.

Product sheet: https://mepospower.com/index.php/products/dc-dc-converters/item/250-3w-150w-dc-dc-converter-isolated-board-mount#datasheet-pdf

[Crissa]

The instructions say to trickle charge it over long numbers of hours.

'While I'm using the bike' is not long numbers of hours in comparison to charging the bike.

-Crissa

[pacificcricket]

So first of all, it doesn't need to be that specific unit. I just googled up an example battery pack that has separate input and output at 12v. DC-DC is great, but you'd need to tap into 100v output from the pack bypassing contactor and basically without internal BMS. I think you understand where this is going... So you have two choices then - treat it like a portable power pack, charging it separately whenever needed, or wire its power supply onto the pins of C13 port in parallel with onboard charger.

Now I may have heard something about constant output somewhere on the BMS. If I am remembering correctly, perhaps it can be utilized if not to drive the actual load (even if via step-up DC-DC if it's only 5v), or at least controlling some relay when tapping into 100v while retaining pack management. But that is seriously more complicated than the two options above.

[togo]

Hello,
I am looking for a solution to the following question: on my Zero FXS I have the usual high voltage battery completed with a 12V plug connected to several functions (lights, USB...). When the bike is off, everything is thus shut down. I would like to find a way to keep this 12V plug alive when the engine is off, whether by connecting it differently or adding a external smaller battery. Did someone try these ideas already? Could you advise? Thanks!
Cheers
Hugues

What's the application?  If th end result is to keep something like a microcontroller or a raspberry pi operating, weatherizing a common USB battery brick, an anker or something, might be a simpler solution.

[SnakeeH]

Thank you for your comments. I looked into it and  I would like to install something like that: https://motogadget.com/shop/en/m-unit-blue.html . I discussed with the supplier who says that the best case scenario is to have permanent 12V plug, it shall not be turned off each time the bike is off. They are also saying that the current draw is very low (less that 1 mA). So my wondering is what would be the autonomy with an external battery knowing that I'm mainly using my FSX for going to work, 40 min to go and 40 to return.

[Crissa]

At a draw that low, I'd expect there to be some pin we could steal it off the main board.

-Crissa