Auto Batteries

[Jim Caudill]

There are a couple of ways to deal with this issue of a large inrush of current. One way is with a knife switch where the ammeter is connected across the switch, and the switch is inline with the battery connection. You leave the switch closed for a bit, and then you open the switch to examine the current draw. You can do much the same thing by having your ammeter setup in the normal way, but you use a decent gage jumper lead to make the initial contact. After everything is stable, then remove the jumper.

I have an old Sears auto analyzer that has a swing blade to carry the larger current and then you open it up to see small currents.

 

[AeneasWalks]

I went with Odyssey AGM after two Optimas failed me. They are big in the off-roading crowd. No problems running my QuickJack with them, though I do use them with my motor running to be safe. Here's an old thread on them (link) from the Land Cruiser forum. Odyssey is Enersys.

 

[Matt The Hammer]

Anyway, I am not above buying a $49 battery at Walmart and just having low expectations.

Same. Low expectations and a Walmart every 7 miles with employees that don't give a **** and will just throw you a new one.

That said - my $49 beauties have done better than I hoped...

 

[Augus7us]

I just bought a battery and my issue was finding one local. I read up on the Toyota forums and it seemed Northstar and Odyssey were recommended the most. However I could not find anyone local that carried these.

I didn't call any independent shops, but I did call napa, autozone, advanced, etc. Seemed they all had house brands. In the end I went with a duralast platinum because I wanted an AGM. So far so good after about 2 weeks.

 

[White Shadow]

The best/easiest way to check for parasitic draw on a modern vehicle is to check the voltage drop across each fuse, one at a time. No worries about disconnecting the battery or using an amp probe, etc... The only thing you need to do on a newer car is to get all the latches (hood/door/trunk) closed and allow the car to go to sleep.

Quick and easy....and you are checking each individual circuit as you go, so you immediately know which circuit is causing the problem.

 

[unslow1]

The best/easiest way to check for parasitic draw on a modern vehicle is to check the voltage drop across each fuse, one at a time. No worries about disconnecting the battery or using an amp probe, etc... The only thing you need to do on a newer car is to get all the latches (hood/door/trunk) closed and allow the car to go to sleep.

Quick and easy....and you are checking each individual circuit as you go, so you immediately know which circuit is causing the problem.

This works great if the draw is constant. When it's not then you have to resort to meter in line or amp probe.

 

[nadogail]

IMHO, park in the sun and keep a solar battery booster on the dash and plugged into the 12 Volt socket.

That solved my problems with a van that is only driven one or two days a week.

 

[White Shadow]

This works great if the draw is constant. When it's not then you have to resort to meter in line or amp probe.

True, but if it's truly a parasitic draw, then it should be constant. If it's not, then you still have to catch it while it's drawing, despite the method. And any draw that is enough to kill a battery in a reasonable time without also being constant, well, that must be one big draw, no?

 

[unslow1]

True, but if it's truly a parasitic draw, then it should be constant. If it's not, then you still have to catch it while it's drawing, despite the method. And any draw that is enough to kill a battery in a reasonable time without also being constant, well, that must be one big draw, no?

Trained by Techs channel had an interesting one. Back interior light switch between off and on light not actually on. Every 15-20 minutes the dash would wake up because of it. Once the dash woke up it woke up the radio. That tiniest of draws was waking everything up at regular intervals because of the computer. Bernie at Automotive Test Solutions does all kinds of these weird ones if anyone likes watching that stuff.

 

[Wrench97]

True, but if it's truly a parasitic draw, then it should be constant. If it's not, then you still have to catch it while it's drawing, despite the method. And any draw that is enough to kill a battery in a reasonable time without also being constant, well, that must be one big draw, no?

In todays stuff the craziest things will make modules wake up, I've had GM's that didn't like the insurance company tattletales plugged into the DLC and the gateway or body modules would wake every other module up and pole them about a unknown module every x number of minutes. Same goes for those company vehicles with GPS/tracking installed had a Ford Escape wake up every 20 minutes and draw 12 amps for a coupe minutes then drop to 20mili amp after 5 minutes only to spike back up 20 minutes later.
If you run the car everyday no issues go on vacation for a week or make it a spare care in the fleet the battery is dead when you need it.