Battery Brain?

While not a Mercedes I'm having problems with my GMC van's parasitic drain, which I can't find for the life of me. I see this item "Battery Brain" http://www.batterybrain.com disconnects the battery when voltage drops below 12V. It's a resettable switch, can handle high currents, and seems like a good idea for my need. Anyone ever try, or is using, one of these? Thanks.

[zafarhayatkhan]

I installed it on my car. I got the remote control version. Works great.

[Benz300]

seems like a good tool. I've got a beemer that has the same exact problem of battery drain. I usually just unhook the positive cable when I leave it standing for more than a week.

[donbryce]

I've had one of these on my infrequently driven street rod for about 5 years, never failed me yet. http://www.prioritystart.com/ BTW, if you google parasitic drain, or search here, there's lots of info on how to trace the fault down. My problem is in my alternator, and it will get repaired soon (yeah, right!)

[Richard Wooldridge]

Hi there,
Keep in mind that every time the battery is totally disconnected from the ECM it will lose all the settings, so your van won't run right until you've driven it for 15-20 miles, because it will start off with the default settings. Same with the radio station settings. If you can wire the battery brain to bypass the ECM it should be ok to use.
Usually that sort of battery drain is due to the "keep alive" wire to the radio. Some radios draw as much as 70 ma when the vehicle is off.

[Benz300]

good point.
does the gadget that is mentioned earlier in the post, keep the settings for ecm intact ?

[zafarhayatkhan]

With optional wiring, it can keep any circuit intact. It can be turned off manualy (repair shop, towing etc).

It disconnects the battery at 12 v. The remote can be used to connect or disconnect the battery as well.

The non-remote version requires manually pressing the button on the unit to connect battery after automatic disconnect.

[Mister Byrnzoil]

the gm TSB on "Parasitic battery drain" states that the draw should be 7-10 milliamps... never more that 30ma.

They mention a 'shunt' switch w/ multimeter for testing purposes instead of just using a multimeter.

[autozen]

Why not correct the problem?

[Ralph69220d]

Originally Posted by autozen

Why not correct the problem?

I agree with autozen. There are a number of tutorials explaining how to measure current draw from the battery while you pull one fuse at a time.

[Mike Murrell]

Originally Posted by zafarhayatkhan

It disconnects the battery at 12 v.

I have read this comment repeatedly here and elsewhere.....12v.

Does this means 12.0v or < 12.60v which is considered to be an acceptable battery volt. reading at rest and after the car has been off for approx. 8 hrs.

If my MBs open circuit volt. reading was 12.0v, the starter wouldn't turn, let alone start the car. Once my OCV reading gets to around 12.15v to 12.20v, it's all over.

It would be interesting to know at exactly what volt. reading this thing wakes up?

*****************************************************************************************
Time for an update - I should have simply done this earlier. I contacted the company that makes PS and asked at what volt. the device deactivated the battery. Here's the reply I got.
*****************************************************************************************

It deactivates at 11.7 Volts. We have thousands of PriorityStarts! sold and this factory setting has not been a problem.

Usually, after the PriorityStart! has activated (or disconnected at the 11.7V threshold), the battery voltage tends to bounce back over 12V once the draw is cut off.

Ed Roseberry,
BLI International,
General Manager
(818) 363-5390
eddie@prioritystart.com
www.prioritystart.com


You can form your own opinion of this device. In my case, it would be of no use as implied above in this post.

[zafarhayatkhan]

Mike,

PriorityStart and battery brain are two different products.

http://www.batterybrain.com/

I performed the folowing test on battery brain:

Turned on the headlights, interior light, radio etc. to the point where the battery brain disconnected the battery. Used the remote to connect the battery and started the car normaly.

Do not recall the battery voltage at disconnect.

[Mike Murrell]

Originally Posted by zafarhayatkhan

Mike,

PriorityStart and battery brain are two different products.

Zafar:

You are correct, but they do the same thing - disconnect battery once volt/amp has dropped to a specific level. PS disconnects at 11.70v which is pathetic in my opinion.

Time to send a query to the other guys.

[autozen]

I'm sorry, but I'm having a problem with all the dialogue here.Just correct the problem with the drain and forget about it. If you have a pre CAN car, put a 1 ohm 10 watt resistor in series with the negative lead and slap a digital volt meter across it. If you read over .05 volts, keep pulling circuits until you drop below that. If you have a late 90s car with CAN, you may have a circuit that is not going to sleep. You need to find out which circuit that is. This battery brain thing is probably marketed in J.C. Whitney and all Slam Auto stores.

[zafarhayatkhan]

Mike,

After locking the car, I would press the button on the remote control to disconnect the battery. This way, the battery would stay at full charge. Allowing the battery to drain is not a good idea.

The automatic disconnect would come in handy if someone forgets to press the remote control button.