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Voltage boost 24 -> 36v on the fly

Posted: Sat Sep 30, 2017 1:51 am
by 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.

Re: Voltage boost 24 -> 36v on the fly

Posted: Sat Sep 30, 2017 1:09 pm
by 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.

Re: Voltage boost 24 -> 36v on the fly

Posted: Tue Oct 24, 2017 7:23 pm
by Quinc
did you figure it out?

Re: Voltage boost 24 -> 36v on the fly

Posted: Wed Nov 29, 2017 10:35 am
by 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.

Image

Re: Voltage boost 24 -> 36v on the fly

Posted: Wed Nov 29, 2017 10:41 am
by 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.

Re: Voltage boost 24 -> 36v on the fly

Posted: Wed Nov 29, 2017 10:44 am
by 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.

Re: Voltage boost 24 -> 36v on the fly

Posted: Thu Nov 30, 2017 3:08 pm
by hookemdevils22
Wire a momentary switch to a relay, in order to control the extra battery cut-in.

Re: Voltage boost 24 -> 36v on the fly

Posted: Thu Nov 30, 2017 3:10 pm
by hookemdevils22
Wire a momentary switch to a relay to control the 12v battery cutout.

Re: Voltage boost 24 -> 36v on the fly

Posted: Sun Apr 15, 2018 3:42 am
by veggysaurus
Nah, thought about running another controller and motor, but going brushless 48v 800w with a 30a continuous and 50a burst controller