[veggysaurus]

Hey peeps,

I have been running a 24v 32AH battery n XYD 500w motor on my e300 for the last year. I can get a 20mile or 32km return trip with batteries charge to 4.2 and end of trip 3.82v per cell. Now I have some spare space under the deck to fit a home made 18650 12v pack I have scrounge from dead Dell laptop batteries at work.

I read on an endless-sphere FB page a dude had a switch connecting a 12v straight to the motor so he could have extra acceleration when needed.

Issues and best practice?

There are times when it would be nice to get up a Hill or pass someone at a push of a buttom!

Dave.

[veggysaurus]

Depending if I go a 3s3p or a 3s4p I should be able to fit around 10Ah in there for the over volt function.

[Quinc]

did you figure it out?

[hookemdevils22]

You could likely wire the extra 12v battery before or after your 24v pack, and use a SPDT relay triggered by a momentary switch. Tie the normally closed relay pin to the 12v negative, normally open pin to the 12v positive AND the controller. I've made a rough schematic detailing how it could be wired.

Grab a relay and switch rated for 36v and you should be ready to rock.

[hookemdevils22]

You should be able to do this with a SPDT relay controlled via a momentary switch. The 24v battery positive (or negative) connects to pin 30, then the normally closed (87a) pin to the controller. Wire the normally open (87) pin to the 12v battery negative (positive). Then tie the 12v positive (negative) and momentary switch into the 87a circuit; ground the other side of the switch. I've attached a rough diagram showing how this can be done.

Grab a relay and switch rated for 36v and you'll be cooking.

[hookemdevils22]

You should be able to do this using a SPDT relay controlled by a momentary switch. Normally closed pin (87) would bypass the 12v battery, while the normally open pin (87a) would provide the 12v boost at the push of the switch.

[hookemdevils22]

Wire a momentary switch to a relay, in order to control the extra battery cut-in.

[hookemdevils22]

Wire a momentary switch to a relay to control the 12v battery cutout.

[veggysaurus]

Nah, thought about running another controller and motor, but going brushless 48v 800w with a 30a continuous and 50a burst controller