Author Topic: Battery gets hot! (Read 2264 times)

bighappy11 · « **on:** May 07, 2009, 12:46:02 AM »

beginner here.

i have a very simple setup with a single (AA)1.5V wired to an ON/OFF button switch to a small 1.5-3VDC motor (all radioshack products). Within 30 seconds, the batter gets extremely hot! Hot to touch. I dont understand why the battery heats up. Help? am i missing a very simple step?

Thanks!

unicoder · « **Reply #1 on:** May 07, 2009, 12:56:32 AM »

how much load is on the motor? as far as anything heating up that is electronic its this: Heat = current passing through a resistance. So if you havnt changed any ressistance something about the current flow has changed. IE maybe the motor is drawing too much current by being under too much load. u should measure your current at line and then load wide to verify

SmAsH · « **Reply #2 on:** May 07, 2009, 01:13:18 AM »

the main reason i can see for a battery getting hot is a short somewhere in the circuit...
check your circuit for possible shorts and fix if any are found...
another reason may be that the motor is pulling too much current...
if you have access to a multimeter chuck on the current setting and see how much current is going through.
good luck with this mate!

bighappy11 · « **Reply #3 on:** May 07, 2009, 01:14:50 AM »

at no load, the motor has 018-0.25A.

see this first test run in the schematic diagram attached.

bighappy11 · « **Reply #4 on:** May 07, 2009, 01:16:34 AM »

by the way, iit gets hot with the motor is OFF.

unicoder · « **Reply #5 on:** May 07, 2009, 01:18:25 AM »

from the looks there
when the motor runs when switch is on. however the switch being on also shorts pos to neg on the battery. hook pos to switch leg 1 then from sw leg 2 hook to motor term. then from other motor term hook to neg on battery

SmAsH · « **Reply #6 on:** May 07, 2009, 01:19:56 AM »

i think that is because the way you have it wired is shorting the battery when the motor is off XD
i use this method a lot when i mod my guitars with kill switches...
but for this app try wiring it like this...
(neg of battery)-(motor terminal)-(motor terminal)-(one side of switch)-(other side)-(pos of battery)
and report back with results...

bighappy11 · « **Reply #7 on:** May 07, 2009, 02:00:39 AM »

smash, errr...it didnt turn on.

like this? see attachment..

SmAsH · « **Reply #8 on:** May 07, 2009, 02:03:13 AM »

nonono, my bad, don't bridge the motor terminals, that applies brakes XD
hook up like attached.

bighappy11 · « **Reply #9 on:** May 07, 2009, 02:36:57 AM »

works! doesnt seem to be heatin' up....
thanks smash! sorry about my incompetence...

now, how to go toggle it in reverse......

unicoder · « **Reply #10 on:** May 07, 2009, 02:40:34 AM »

just reverse the polarity of the input current
ie change which terminal the switch and neg run to

if you use two different switches(one for each direction) remember not to have both direction enabled or youll hit same prob u just had

SmAsH · « **Reply #11 on:** May 07, 2009, 02:43:45 AM »

aha! one way to integrate a toggle to get both directions is like attached. this allows to switch between "forward" and "reverse" easily... you will need a dpdt switch to do it.

unicoder · « **Reply #12 on:** May 07, 2009, 02:46:32 AM »

thats what i was thinking but im new to small electronics lol. Only things im used to are for things like industrial motors with cam switches etc. I need to get some of those lol

SmAsH · « **Reply #13 on:** May 07, 2009, 02:48:55 AM »

you will get used to this stuff soon enough, then it will be as easy as breathing... almost...

TrickyNekro · « **Reply #14 on:** May 07, 2009, 09:29:33 AM »

Quote from: SmAsH on May 07, 2009, 02:48:55 AM

you will get used to this stuff soon enough, then it will be as easy as breathing... almost...

bighappy11 · « **Reply #15 on:** May 07, 2009, 11:02:40 AM »

ill attempt to install a dpdt switch.

thanks again guys. very helpful.

SmAsH · « **Reply #16 on:** May 07, 2009, 02:52:23 PM »

happy to help

just a side note of useless info:
this is a good way to set up your first h-bridge with relays... and transistors, yummy transistors...

bighappy11 · « **Reply #17 on:** May 07, 2009, 03:12:19 PM »

baby steps, baby steps...

SmAsH · « **Reply #18 on:** May 07, 2009, 04:02:17 PM »

im just saying... aspire mate, aspire!

bighappy11 · « **Reply #19 on:** May 07, 2009, 04:36:14 PM »

no, of course! you are very right. thanks for your words of encouragement......I foresee a blossoming relationship in the near future.

Soeren · « **Reply #20 on:** May 07, 2009, 04:59:32 PM »

Quote from: bighappy11 on May 07, 2009, 04:36:14 PM

[...] I foresee a blossoming relationship in the near future.

Hey, get a room you two

bighappy11 · « **Reply #21 on:** May 07, 2009, 05:06:07 PM »

how does Motel 6 sound?

unicoder · « **Reply #22 on:** May 07, 2009, 06:39:31 PM »

u can both sleep over on my couch.

SmAsH · « **Reply #23 on:** May 08, 2009, 01:44:44 AM »

yay? when you come to australia you can sleep in my robot...

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Author Topic: Battery gets hot! (Read 2264 times)

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