Over or Under Volting Speed controllers ???

Electric Motors and Controllers
Post Reply
johnnyfoos   1 mW

1 mW
Posts: 14
Joined: May 03 2013 9:52am
Location: South East IDAHO USA

Over or Under Volting Speed controllers ???

Post by johnnyfoos » Oct 20 2018 3:24am

Hello,
I have a question about speed controllers-
Regarding The Voltage
How Under or Over these can handle and still work with letting out the smoke??
What I have on hand-
(YK31C 500W 24V and 36V){one of each}
(LK-03 350W 24V)
Brushed motor controllers

The "WHY"-
My reason-
The batteries on hand-
When the local Radio Shack was closing down last year
I stocked up on these,(very cheap)
"DigitalEnergy" Packs, {20+ packs}
NI-MH, 9.6V, 1600mAH, 8 cell packs
When fresh off the charger 10.6V
I don't want to reweld/rebuild these packs, (no spot welder)
my 4 different chargers can NOT even charge these in 2S, (only 15 cells max)
So I'll have to rack them up in a box that lets me 3S or 4S, X 3 or 4 P
(30 volts into the 24V controller? or the 36V one?)
(40 volts into the 36V one?)

The Ride-
A rebuilt Razor Electric Punk,
( with the folding collapsing still working to hopefully still fit into a suitcase)
stretched front end, suspentioned, racked back with a 12.5x2.25 three spoked wheel
Lengthened and widened rear wheel mount with a FREE Wheeled 10x35-4 with two extra spring shocks
replaced the 12V, 80W motor, still using stock mounting system, Tensionable drive belt

Waiting for a battery system-

installed for scare testing-
MY1016, 18V, 2700RPM, 150W, 10.9A
If 150W wasn't to BAD,
ON hand- ( using same mounting hole pattern)
MY1016, 24V, 2750RPM, 300W, 16.4A unite motor
MY1018, 24V, 2500RPM, 300W, 16.5A JX motor

So-
PLEASE let me know what you think about the battery and controller problem I have

NO! I don't want to BUY Li- anything right now
I've got all those NiMh's and a big box of Ni-Cads, ALL NEW needing to get used!

Just
Asking

User avatar
amberwolf   100 GW

100 GW
Posts: 25468
Joined: Aug 17 2009 6:43am
Location: Phoenix, AZ, USA, Earth, Sol, Local Bubble, Orion Arm, Milky Way, Local Group
Contact:

Re: Over or Under Volting Speed controllers ???

Post by amberwolf » Oct 20 2018 5:39pm

How low depends on the controller's LVC. If they're not marked with that, you'd have to test each one to see what voltage it shuts down at.


How high depends on the voltage limits of the parts inside the controller. Usually the capacitors (the largest can-shaped ones) and the FETs are the main limiting factors, but there could be other parts in the high voltage side of the low voltage power supply that limit it.


Regarding NiMH or NiCd: NEVER charge them in parallel.

You may get away with discharging them in parallel, but charging them that way could cause a fire, because of the way they drop in voltage once they reach full charge.

johnnyfoos   1 mW

1 mW
Posts: 14
Joined: May 03 2013 9:52am
Location: South East IDAHO USA

Re: Over or Under Volting Speed controllers ???

Post by johnnyfoos » Oct 21 2018 4:25am

amberwolf-
thank you.

"charge these in 2S"
The S means series
ya know

User avatar
amberwolf   100 GW

100 GW
Posts: 25468
Joined: Aug 17 2009 6:43am
Location: Phoenix, AZ, USA, Earth, Sol, Local Bubble, Orion Arm, Milky Way, Local Group
Contact:

Re: Over or Under Volting Speed controllers ???

Post by amberwolf » Oct 21 2018 10:39am

Yes, it does, but you also mention "3P or 4P" up there, which means paralleling packs--which with nickel chemistries isn't safe for charging. If you parallel them for discharge, then charge them forgetting you've done that, you can end up with a fire.

Post Reply