3rd Generation Specific (1993-2002) 1993-2002 Discussion including performance modifications and Technical Support Sections.
Sponsored by:

Can't keep a charge

Thread Tools
 
Search this Thread
 
Old 05-10-11, 02:56 PM
  #1  
Rogue Engineer

Thread Starter
 
danewbern's Avatar
 
Join Date: Nov 2009
Location: Plano, TX
Posts: 95
Likes: 0
Received 3 Likes on 3 Posts
Can't keep a charge

Guys-

I have been chasing a problem for a while and was hoping someone could help. I did a conversion to a vmount IC last year and relocated my battery to the bin behine the driver. At rotary performances reccomendation, I used a miata battery and connected the positive to the starter. For some darn reason, it can't keep a charge on the battery. After I put it on my charger, it powers full charge but there is not enough juice to do anything.

I even tried swapping to a new battery. Aftter a month, I am dead in the water again. Does anyone know of a good way to tell if there is a constant drain on power and how I can track it down?

Thanks,

Dan
Old 05-10-11, 05:04 PM
  #2  
Rotary Freak

iTrader: (24)
 
AzEKnightz's Avatar
 
Join Date: Apr 2005
Location: California, SF
Posts: 2,488
Likes: 0
Received 7 Likes on 5 Posts
Put a DVOM in series with the battery (dvom negative lead to battery negative post, and dvom positive lead to battery positive post)

All doors "closed" (I recommend having them open and use a screw driver to lock them that way ur interior lights will not stay on)

Then put the DVOM in AMP setting to see what kind of amperage draw you have after 30 minutes sitting.

It should stay below 200mA. If you have something higher than that, start pulling fuses one by one and check the amperage draw. The one fuse that you removed and the amperage draw drops, you found the circuit for the draw.

Then start from there to figure out what's draining the battery dead.

-AzEKnightz
Old 05-10-11, 07:27 PM
  #3  
Recovering Miataholic

 
wstrohm's Avatar
 
Join Date: Mar 2002
Location: Fountain Valley, CA
Posts: 1,531
Received 38 Likes on 26 Posts
It should stay below 200mA.
Our '94 reads about 13 mA.
Old 05-11-11, 11:04 AM
  #4  
Rotary Freak

 
mad_7tist's Avatar
 
Join Date: Jan 2004
Location: tampa
Posts: 1,899
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by AzEKnightz
Put a DVOM in series with the battery (dvom negative lead to battery negative post, and dvom positive lead to battery positive post)

All doors "closed" (I recommend having them open and use a screw driver to lock them that way ur interior lights will not stay on)

Then put the DVOM in AMP setting to see what kind of amperage draw you have after 30 minutes sitting.

It should stay below 200mA. If you have something higher than that, start pulling fuses one by one and check the amperage draw. The one fuse that you removed and the amperage draw drops, you found the circuit for the draw.

Then start from there to figure out what's draining the battery dead.

-AzEKnightz


/\this is wrong.


disconnect the battery neg
clamp the Multi meter lead to the neg battery terminal
clapm the pos lead to the neg battery cable (while not attached to the battery)
set the meter to amps

if you do it across the battery terminals it will blow the meter fuse
Old 05-11-11, 01:48 PM
  #5  
Don't worry be happy...

iTrader: (1)
 
Montego's Avatar
 
Join Date: Apr 2001
Location: San Diego, CA
Posts: 6,846
Received 787 Likes on 463 Posts
Originally Posted by mad_7tist
set the meter to amps

So what's a good reading threshold?
Old 05-11-11, 02:10 PM
  #6  
Rotary Freak

 
mad_7tist's Avatar
 
Join Date: Jan 2004
Location: tampa
Posts: 1,899
Likes: 0
Received 0 Likes on 0 Posts
less than 100mA. less than 50mA ideally some aftermarket stuff will change that like an alarm etc
Old 05-11-11, 03:04 PM
  #7  
Don't worry be happy...

iTrader: (1)
 
Montego's Avatar
 
Join Date: Apr 2001
Location: San Diego, CA
Posts: 6,846
Received 787 Likes on 463 Posts
thanks for answering.
Old 05-11-11, 03:44 PM
  #8  
Rotary Freak

iTrader: (24)
 
AzEKnightz's Avatar
 
Join Date: Apr 2005
Location: California, SF
Posts: 2,488
Likes: 0
Received 7 Likes on 5 Posts
Thumbs up

Originally Posted by mad_7tist
/\this is wrong.


disconnect the battery neg
clamp the Multi meter lead to the neg battery terminal
clapm the pos lead to the neg battery cable (while not attached to the battery)
set the meter to amps

if you do it across the battery terminals it will blow the meter fuse
LOL, thanks for catching it. I meant

"DVOM negative lead to negative post while DVOM positive lead to GROUND CABLE."

By the way, I also meant 20mA NOT 200mA. But as mad_7tist stated, 50mA should be ok if you have aftermarket alarm and sound systems installed.

My apologies, I was busy at work and had couple of mistakes.

-AzEKnightz

Old 05-14-11, 01:12 PM
  #9  
Rogue Engineer

Thread Starter
 
danewbern's Avatar
 
Join Date: Nov 2009
Location: Plano, TX
Posts: 95
Likes: 0
Received 3 Likes on 3 Posts
Thanks Guys. I'll give it a try and report back
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
SRTx781
3rd Generation Specific (1993-2002)
6
12-19-15 07:30 PM
alexdimen
3rd Generation Specific (1993-2002)
20
10-23-15 01:50 PM
FC3S Timmy
2nd Generation Specific (1986-1992)
16
10-03-15 01:08 AM



Quick Reply: Can't keep a charge



All times are GMT -5. The time now is 04:05 PM.