controller that can use 24v and 36v

[jay7264]

hey everybody i posted a week ago about building a 36v 12ah battery and i was wondering if theres a controller that can switch to 24v or 36v. my motor is 24v 250 watt brushless geared hub. the reason i would like to be able to switch voltage is i want to keep my 24 volt battery now that i got it beefed up im able to make my commute to work 8 miles with light peddling on hills. it would be nice to have a controller that can switch on the fly via a toggle switch or something is this a possibility?

 

[maurtis]

Are you talking about using two different batteries, a 24V and 36V, and switching between the two? Or using one 36V battery, but with the option of using less voltage?

If you are looking to use just one battery, it sounds like you should get a controller with one of those three speed switches, or method's universal switch.

If you want to switch between two different batteries, since a 36V controller will likely have an LVC, maybe just get a nice 24V controller? They can usually take 36V fine and you are not running many amps anyways. And then rig up a manual switch to go between batteries, or take the easy route and just unplug one and plug in the other as needed?

 

[jay7264]

if i use a 24 volt controller with 36 volts the lvc will be very low and could ruin the battery if im not carefull correct. but the batterys im putting together have built in bms they are a copy of the yardworks batteries 20v 6ah lithiOn so you are probably right about just getting a quality 24 volt controller

 

[d8veh]

If you're going to use your 24v controller with the 36v battery, check that the BMS does actually shut down the battery when it's low. Many don't.

 

[dogman dan]

You just need a 36v controller with a very low, low voltage cutoff setting. One set to 22v would work. There wouldn't need to be any switch. But you would not have the controller lvc doing any good to you when running it on 36v. Depending on the lvc to know when too stop and charge is a bad plan anyway. Get a voltmeter, and stop much sooner than the lvc would stop you.

A guy like Lyens could make the adjustment to his small controller for you.

 

[jay7264]

I tested the batteries I'm getting on one I had with the cordless weed whacker and yes the batteries built in BMS lvc does work. Verified after it stopped I opened it up checked cell voltage and it was 3.2v per cell.

 

[d8veh]

You'll be OK then. Most 24v controllers can handle 36v.

 

[dogman dan]

To be sure it can, open the controller and look inside. Look for little tiny cans with a number on the side. If they say 30v, then 36v might cook them. But chances are they are 50v capacitors in there.

Most likely the factory just makes one controller, and just sets the lvc different for a 24v motor. So lots of 24v controllers can run on 36v.

 

[jay7264]

you know what im really getting addicted to this ebike so many people ask me questions about my evg ebike and plenty of compliments. the bike is growing on me and i love the potential that it has. its looking real good after being buffed out with plastic polish i cant wait o be able to afford a bigger motor something like 500 watt or maybe 1000 geared i love the sound and how i dont even know its there when riding normally

 

[middriveebike]

A dual mode controller does exist.
I got one that can use both 48V and 60V. However, you need to connect the learn connector before switching to another voltage.
It will change the LVC at the same time.
However, if you do the learning when the battery is higher than 52V, it will think you are on 60V and set the LVC accordingly.

Dual mode for 24V/36V also exist. You may need to try really hard to look though.