Minor Modification Question - Charger Door Switch

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PJD
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Minor Modification Question - Charger Door Switch

John, or Eric,

Something that I've always thought could be done better is that door hinge actuated, normally-closed switch for turning on the BCU and BMS charging. A failure of the switch lever mechanism or the door hinge (which holds the switch open) when the scooter is unattended or in storage would leave the battery pack slowly discharging.

Sure, it would take a long time - about 25 days - to discharge the battery pack completely flat, but we are talking a probable ruined battery pack if it does happen - a similar situation to a car's engine being ruined if the dome light is ever left on. A better fix is to have the charging circuit actuated only when the charging cord is actually plugged in.

So, I am thinking about replacing the door switch with a relay actuated by the 110 volt mains. Since I have a timer switch for the charging outlet in the garage, this provides a "plug and forget for days" solution. Would there be any technical issues I may need to know about before doing this?

Thanks,

Paul

ErikK
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Re: Minor Modification Question - Charger Door Switch

Paul -
On one hand, that's a pretty good idea. I have no objection if you want to do it. I'm sure I don't need to tell you to be careful about the 120vac safety and insulation issues. :-) Other than that, there are no particular technical issues with this modification. We considered this idea when designing the bike, and decided not to use a 120v relay because we didn't want to get tangled up in UL approvals for the 120vac side of the system.

On the other hand, I just measured current draw on a bike here at the shop. Current out of the pack is 3ma when everything is off, and 23ma when the charge door is open. So by my math it would take something like 100 days to completely drain the pack by leaving the charge door open.

-- Erik

-- Erik Kauppi, Chief Engineer, Current Motor Co --

PJD
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Re: Minor Modification Question - Charger Door Switch

Erik,

Thanks for the info - .23ma is a lot less than 100 ma.

Just the same, I like the "elegance" of a relay solution. One other thing it fixes is the arcing upon plugging the power cord in. The only inelegant part is that they don't seem to make miniature 120 VAC coiled small-current/signal relays. So I'll use a slightly chunky (compared to a micro switch) Zettler 30A power relay with recessed connectors for safety.

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