Limit Voltage Coming from Battery so not break the Controlle

[broloch]

If I have a powerful battery pack, is there a way that I can limit the voltage coming off the battery a little bit to prevent it from destroying my controller?

e.g. if I got an Infineon 24-48V controller that is limited to 60V max, and the battery gives off a bit more like 62V, can I make it so the battery gives out
only like 58V max?

I was thinking of some simple contraption that adds on via connectors.

 

[Anonymous]

.

 

[amberwolf]

How about a zener-diode-controlled relay that puts some big fat heatsinked diodes in series with the battery-to-controller circuit until the voltage falls below the cutoff you set with the zeners, at which point the relay powers off and the contacts wired across the diodes close, shorting them.

That would keep the whole pack voltage from showing up at the controller, only the pack minus the diode drops, until the cutoff is reached and then the full remaining voltage is now at the controller.

Diodes would waste a considerable power across them, but they'd only be in circuit for the time taken to drain the pack a little.

 

[broloch]

Interesting points, thanks guys.

The problem started when I put a nominal 60V (off charger at 70V) on my Crystalyte RoadRunner controller (48V, 20A).
The power indicator light failed to go on, and the controller no longer worked after that.

I must have blown a part or something.

 

[amberwolf]

Depending on what they have in there, and how they design their low-voltage power supply, it could be something very simple, or it might look like a bomb went off.

 

[dogman dan]

70v though 60v caps would be a high potential for the controller to blow.

The 62 volt battery puts out 62v after a minuites use? Sometimes a fresh charged battery has a higher surface charge that disappears as soon as it's used for a few seconds. You might be ok, but of course the safety margin would be a lot better with a 72v controller. $200, ouch!