Tata Tiago battery discharge problem

BHPian izzikio_rage recently shared this with other enthusiasts.

Wanted some advice on our Tata Tiago Petrol 2017 model. Due to the pandemic, the car has been a bit underused however the battery has been discharging very rapidly (in less than 2 weeks) even with long runs between these idle periods (20 km+ per run). The car has gone to the Tata Workshop in Gurgaon almost 3-4 times now and still, there are no results. Before this, the car has been used frequently for over 3 years with no issues at all.

Things tried

1. Changed battery - did not help

2. Workshop kept it for a few days to check for 'current leaks', after the 3rd visit something worked and it remained trouble-free for 2 months now it has discharged again

3. We've tried to run it multiple times a week and it works fine, however even after that, if you leave it for 2 weeks odd, the battery is completely drained (even the remote unlock and dashboard indicators don't light up)

Any suggestions on what I should try next or if there is a highly recommended Tata service centre in Gurgaon that could help solve this. Pretty much at my wit's end.

Here's what BHPian gkveda had to say on the matter:

There can be only two possibilities.

1. If you have installed any Accessories (local or Chinese), they would be draining the current. If there are no Accessories installed, some OEM electrical parts must be draining the current.

2. The alternator is not charging the battery when the car runs a long distance. So, the battery is drained by electric parts and not getting recharged.

To find out the cause of the problem, Suggest you start your journey in the morning after resting the car for a week.

1. Before starting the car, check the battery voltage. Let's say it is A Volts

2. After running the car for 4-5 hours check the battery voltage immediately after ignition off. Let's say it's B Volts

3. Check the battery voltage the next day. Let us say it is C Volts

Now analysis goes like this.

After step 2, if the voltage(B) has not increased significantly from the initial measurement (ideally it should be rated voltage 12.5 V) and it is say 8 or 9 V, then it is an alternator issue. It simply means that the alternator is not charging the battery. If it is 12.5 V then, the alternator is charging the battery and it is working fine.

After step 3, if the battery voltage is reduced to say 8 or 9 V, it is an issue with current leakage in accessories or electric parts of the car.

Here's what BHPian Indian2003 had to say on the matter:

20+ kilometres is not a long run and it will hardly replace the current used to start the car. About 500 km or more is needed to fully charge a car battery with the alternator.

I suspect your car is only being used for short trips every day and your battery is dead and will not hold a charge.

Just a week ago I went on a trip totalling about 300 km with aircon on. When I left, my battery was at 67% and when I returned the battery was at 80%.

Get a new battery and a trickle charger and the problem should go away. A car battery is not a fit and forget item. It needs to be maintained to keep it healthy.

My battery is 4 years old and takes a beating every winter with cold starts down to -25 degrees. I connect a trickle charger about once or twice a month. That way sulphating will be minimal and the battery lasts longer.

Here's what BHPian R2D2 had to say on the matter:

You have a parasitic drain in your car. Have you fitted any aftermarket accessories? Was any electrical accessory changed? Please check the wiring and fuses and perform a drain test yourself using a YT video as a guide assuming you have a multimeter. Otherwise, take the car to a reputed car electrician for troubleshooting.

Also, check alternator diodes, these are the most innocuous of drains and most people look in every nook and cranny of the vehicle for the cause of trouble but almost never check the diodes. You will see a thick red wire connected to the alternator that is the main output wire which charges the battery. It is connected to the battery +ve post via the main fuse (referred to as "Alt" or similar) in the fuse box. Check the temperature at that spot in the morning letting the engine cool down overnight. Normally a shorted diode will cause that spot to be warmer than the surrounding metal.

Good luck, an electrical issue can be very frustrating and requires patience and diligence to trace and fix. But it can be done.

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