Hello,
I have a used 2006 Daihatsu Sirion, I changed the battery a bit less than a year ago and also the alternator is new ( a few months old ).
When I turn on the lights, the radio, the emergency flashers the car battery dips from 12.85 to 2.1volts and the head lights dim.
When I use the electric windows the speed they go up varies according to the rhythm of the emergency flashers lol and one time when driving in the night with the lights on + radio when I used my turn signal to turn the radio turned off and on.
I guess its safe to say I have been given a bad battery correct ?
Thank you
Chris
Your problem can be caused by poor cable connections. Check/clean/tighten them first.
You may have been given a perfectly good battery. But if your alternator was failing at the time, and not charging it properly , then that could have damaged it.
Why guess? Get a free battery test done. Many places do it.
When I turn on the lights, the radio, the emergency flashers the car battery dips from 12.85 to 2.1volts and the head lights dim.
was the engine on or off?
The battery is a Katana b438c 40Ah 330A. Is it too small a battery ?
The battery's ONLY job is to start your car. The alternator runs your accessories.
12.1 V with the engine off, and all those accessories on is not unusual.
When I turn on the lights, the radio, the emergency flashers the car battery dips from 12.85 to 2.1volts and the head lights dim.
was the engine on or off?
When I did the test the engine was off.
But when I drive at night if I brake the lights dim. If use hazard lights the headlights fluxuate their brightness according to the rhythm of the hazard lights. Same thing happens with the electric windows their speed going up or down fluxuate according to the rhythm of the hazard lights.
Once I had the radio go off and back on
Test the battery.
Clean off and tighten all your main connections. They cause electrical resistance and make it look like you have a low battery.
What is the correct way to test the battery myself ? ( I have a multimeter, a cheap battery tester and a fancy battery charger that can charge all types of batteries and even reads resistance. )
I clean the battery terminals every now and then gently with a bit of sandpaper, so the terminals are indeed clean and i am sure they are tight I have checked.
Anything else I can do ?
Thank you for your time
there is no substitute for a professional tester I'm afraid. The good news is that battery dealers provide the test for free. Your cheap tester will give cheap results.
You need to check ALL your connections. Not just the battery posts. I'm talking about all the ground connections between your battery, engine, and body. The positive alternator cable. You should check the ground connections of all affected systems (headlights etc.)
Understood thank you, Also should I bother getting a reading of internal resistance of the battery ? ( since I can do that myself ) and if so what would be a good a good value range in ohms ? I know I probably ask too many questions but I prefer learning and being independent .
The carbon pile load tester is the gold standard for car batteries. They're too expensive, it doesn't make sense to buy one unless you run an auto shop.
I just went to have the battery load tested to where I bought it. During the load test the voltage dropped to 8v so the battery is not good.
I got a new different brand battery for free. So far everything looks good I will keep monitoring the battery.
One of the few things missing from my toolkit is a good battery load tester, so I guess I should buy one so I do not have to guess what is wrong
Are you in SE Asia? Because the cheap/lower quality batteries only last for a year on average. I’m guessing yours went before your 1yr warranty expired & they were forced to give you a free replacement..
Actually I am in Cyprus, but I would not be surprised if the shop here I went to buys their batteries from a dodgy supplier in Asia. The battery went bad about 2 months sort of a year.
I will keep replacing the battery as long as they are willing to give me a new one for free and then I will get a proper brand name and probably higher Ah as long as it can fit in the car properly.
I got the car used with a 33Ah 270A battery and the one that got bad was a 40Ah 330a and the new one is the same higher specs but different brand.
My next battery will be a 45Ah one or better.
No worries. A lot of the cheap batteries are made in SE Asia & have horrible quality. Yeah, make them replace it for as long as you have warranty on it. Also, as Scotty recommends, buy the battery from a place which sells a lot of batteries since you don’t want to get a battery which has sat for very long at the shop. The fresher the manufacturing date, the better. Good luck!
if you were using that battery with a failed alternator, that would have damaged it.
Indeed.
I just checked the battery and they installed a 35Ah 270A while they previous one was 40Ah 330A. I specifically asked for exactly the same specs battery if not better they said OK and they installed a 35Ah one lool.
Should I bother to go change it ? I think I should go change it and get the 45A one and pay for the difference.
like I said, the battery only starts your car. Unless you live above the arctic circle, or drive a heavy duty diesel, you don't need special batteries.
https://carkiller.com/scottykilmer/qa/good-1-ton-truck-batteries/#post-70371
If the battery ONLY starts the car why did I had all that weird side effects with the bad battery that went away with the new battery ?
The car never had any issues starting even with the bad battery but the headlights would dim, the electric windows would go up slowly etc.
My guess is the bad battery was using too much power from your alternator which should have been going to your accessories
I just got my battery tester the results look pretty good don't you agree ? :
2 seconds is not long enough for a proper test.
https://www.autobatteries.com/en-us/battery-testing-and-maintenance/car-battery-voltage-and-testing
A way to test the health of the battery with a multi meter is to measure the voltage when you crank the engine. If the voltage drops below 10 V (when cranking before the engine starts) it may indicate the battery is in a bad shape. Last time I did this, the old battery showed 9,8 V fully charged and the new one measured 11 V. This test is not necceserly bullet proof, but gives an indication of the battery health.
I just got the TOPDON AB101 battery tester: