What is Draining the Battery?


#1

My 1995 Nissan Maxima was in the shop for four months, because something is trickling the power from a new battery. Finally they installed a ‘kill switch’, which is suppose to stop all electrical drainage, but STILL something, somewhere is draining the battery. This car is not used daily, instead once a week. Desided to start it every three days to possibly keep the battery charged. Does anyone truly have an answer to this problem?


#2

Do you really need that car? Four months in the shop? Used once a week?

A maintenance charger might be a good solution if you intend to continue using the car.


#3

The best approach is to bring it to a shop that specializes in automotive electrical systems. They’ll have the expertise and access to the schematics to isolate the guilty circuit and correct the problem.

Parasitic drain is easy to check for (can be hard to solve) so I suspect that the shop you took it to has specialties other than the electrical systems. Otherwise they would have not returned the car to you with the parasitic drain still there.

Oh, and if you have an aftermarket sound system, be sure to tell the shop. If it’s installed with splices, be sure to tell them that too.

EDIT: I just realized something, if you’re only using the car once a week are you driving it far enough to charge the battery or just to the corner grocery store? If you’re only going to the corner store, you may need a trickle charger. There may be nothing at all wrong with the car itself.


#4

A kill switch (or battery cut-off switch) located right on the battery positive terminal will remove it from the circuit and the vehicle cannot discharge the battery. I’m thinking that you don’t use the vehicle enough to keep it charged or you have an alternator problem. Has the alternator been checked?


#5

Missileman, you’re assuming the kill switch is properly installed. I’m not so sure, since the shop let the car loose with the problem still intact.

In the end, your suspicions are probably going to be correct. I’m guessing it might be a “once a week to the corner store” car.


#6

I was assuming mountainbike. It seems to me that you should get something right after having it in your shop for 4 weeks. Vehicles are rebuilt in far less time than that.


#7

True. I think in the end we’re both wondering if the car gets driven enough to keep the battery charged. It’d be great to have the OP answer the question. OP?


#8

If the kill switch is installed correctly, and at the battery – and I agree that this is a good idea to try for your problem – it may be the battery is self-draining more than it should. No batteries will remain fully charged indefinitely. Yours could have an internal fault. Or there could be a current path on the outside case of the battery. There’s no simple way to measure either of these currents, other than noting that the battery capacity has drained over time.

The internal drain can’t be fixed and would require a new battery. But the outside drain can usually be fixed. If battery fluid or any electrolyte gets on the case and sticks there, current can flow along the battery case from the plus terminal to the minus terminal and drain an otherwise good battery over time. The way to solve this is to remove the battery from the car, and clean it thoroughly on all 6 sides. I use a weak solution of baking soda and a stiff brush, then a thorough rinse with plain water. Clean the areas in the engine compartment which the battery touches at the same time.

The above assumes your alternator is ok, the battery meets the specs for the car, and is good (passes a load test). And the car must be driven enough to recharge the battery each time. I think 30-40 minutes would be enough to recharge a battery sitting one week. A trickle charger as mentioned above can be used if the car simply isn’t driven enough minutes each week to recharge it.


#9

Just getting back to my posting and truly appreciate all responses. Alternator is good, just replaced the battery again (Auto Zone replaced free), and the Shop I took it to had schematics for reference. It was there for four months because they kept putting it ‘on the back burner’, not a priority. I told them at the beginning, not a rush job, this is the ‘dog’s car’. Wasn’t thinking two-four months down the road. Maybe a trickle charger is the answer. Does it need to be plugged-in all the time?


#10

“Maybe a trickle charger is the answer. Does it need to be plugged-in all the time?”

Good idea. Make sure it’s labeled a battery “companion” or “maintainer.” My Schumacher model is always plugged in and maintains a 20 to 50mA charge rate and 13.8V.


#11

And be sure to read the owner’s manual for the unit you buy. If you follow the instructions you’ll have no problems whatsoever.

If you’re unsure what to buy, ask the guy at the store or write brands and model numbers down and post them her so we can look them up and advise you.


#12

Maybe another, and better, opinion is needed because it’s ridiculous for this to go on for 4 months with the end result being a battery disconnect.
Depending upon the type of disconnect, not everything may be removed from the circuit.

What you need to do is have someone at least perform a parasitic draw test and determine how many Milliamperes are being pulled while the car is sitting. This should take no more than a few minutes and will reveal if there’s an excessive current draw issue if not the actual problem.
That’s the starting point for this.


#13

Will do.