Car requires jump every time. Anyone able to weigh in?
Posted by Fishtickles@reddit | askcarguys | View on Reddit | 76 comments
Hello everyone,
I really dont know much about cars so, I'd appreciate any advice your able to pass on. For context, I drive a Mazda Cx-30.
My car randomly wouldn't wouldn't start today. I have a self Jumpstart kit and was able to get it up and running however it requires a Jumpstart everything I went to drive today. Ive had stretches of driving over 70 miles uninterrupted but, it would still fail to start after parking briefly.
I took it to autozone and had them run a battery diagnostic test and took a voltmeter to it. They said the battery was at 65% and the voltage was slightly lower than expected but, not something that would cause a fail to start. The tech didnt know what the issue was based off those tests.
When I got home I disconnected the battery terminals to look for corrosion but, they seemed super clean.
Anyone have any idea as to what the issue could be?
reidft@reddit
If it stays running after jumping it, something is either drawing power or your battery needs to be replaced. I'd bet the battery first since the car is too new to have parasitic issues, or at least it SHOULD be too new for that.
If there's a red battery light shining on your dash, then your alternator wouldn't be charging.
Fishtickles@reddit (OP)
Could a parasitic power draw explain the battery reading at 65% at test and not being able to start immediately after
reidft@reddit
They might only check if the battery is holding a charge, which is what the 65% would mean. But the battery could fail to pump out enough power when trying to start. I don't know the science behind it, just that charged doesn't always mean it can push enough amps. All the drain would do is empty the battery if it sits for an extended time
04limited@reddit
Yes. Voltage shows how full it is. Crank amps show how power it is. You can have a fully charged weak battery or a low charge strong battery. Both would struggle to start but the latter will start work fine after being charged up.
04limited@reddit
If that’s an original battery(all black, safety label on top no branding or other stickers) it’s likely due for replacement being that the car is 6 years old now. Batteries only last 5-6 years on average.
ClickKlockTickTock@reddit
What do you mean jump it to do the test? If you have to jump a battery to get it to test, the battery is probably bad lmao.
Even if its not the battery, requiring to be jumped this much means the battery is at the end of life even if it isn't the initial cause. Replace battery, and then follow up.
Numerous cases where batteries fail but test completely fine.
saskyfarmboy@reddit
Sounds to me like a weak battery to me. We just changed the batteries on one of our tractors. Fully charged, load testing as weak-but not bad. Would crank and crank and crank but not fire.
Put new batteries in and it fired up instantly.
zerovampire311@reddit
For my case recently, I had a similar read and it was a bad cell in the battery. Same scenario as you with having to jump it every time. My money is on the battery.
porchprovider@reddit
Just buy a battery. I promise, that’s what it is. It’s always the battery.
comfy_rope@reddit
Are you driving the car in short trips?
Radiant-Video7257@reddit
Assuming the battery has never been replaced, replace it. Those things last 3-6 years and you're on year 6. Also 65% isn't enough to start the car when it's already been degrading for 6 years.
Automatic_Mulberry@reddit
"Wouldn't start."
Crank, but no start? Click and a christmas tree on the dash? Nothing at all?
Fishtickles@reddit (OP)
It makes makes a puttering noise like it wants to start if that's what you mean by crank.
Automatic_Mulberry@reddit
"Crank" means that the starter turns the engine. Rrr-rrr-rrr-rrr kind of noise.
From the sound of it, the car runs fine once it's started, and the starter turns the engine okay. Not that batteries are "cheap" these days, but that's probably the least expensive and easiest place to start, and I think it has a good chance of resolving the issue - or the car wouldn't start when jumped.
Informal_Ad4399@reddit
To add in, if you're in the US most auto parts stores will test a battery for free. Starters too for that matter.
OkKnee7580@reddit
I think the starter has to be out of the car. They will test ur alternator tho
Tantalus420000@reddit
Concur
funcentric@reddit
You may need new spark plugs.
Livid-Pilot-1879@reddit
A 6 year old battery is probably the problem, they dont last like the old days. My 2015 Mazda CX5 is on its 3rd battery, and I am very careful about maintainence..
OperationAsshat@reddit
It sounds like the battery is done. Could also be something with the charging system causing an issue, but you would need to check voltage while it is running to verify. If voltage while running is normal and battery is staying below expected voltage when off, even after driving for a while, then the battery is probably the issue.
Also be sure to check voltage directly on the battery terminals and then outward on either side from there. If you have a voltage drop between two points you may be able to determine if there is a corrosion issue causing problems as well.
Fishtickles@reddit (OP)
If memory serves the autozone tech checked with a voltmeter and said it ran slightly lower than expected, not sure if right but, i think he said he read like 13volts and expected more like 14. He didnt seem to think this would be causing the issue though.
MealNarrow6086@reddit
It should be closer to 15. Like 14.6 or so fully charged. Time for a new battery. Walmart Maxx batteries ( not there cheapest ones) and Costcos Interstate (also not the cheapest ones). Many of them are the exact same battery with different labels on them. Costco is usually a bit cheaper but Walmart has a better warranty. Great batteries I can get 8 years usually with them.
ametsun@reddit
It doesn't take much for a battery to be considered dead. If it's down from 13 to 12 it's probably toast. Get a new one.
knoxcos@reddit
14V is when running and the alternator is charging the battery. When the engine is off, a voltmeter would show ~12.6V ideally.
65% tells me that battery is toast. It doesn’t mean the battery is 65% capacity (~8.2V), but a lack of current expected. Likely the anode or cathode has been building up corrosion within.
Info: how old is this battery? (Should be a sticker indicating mo/yr of manufacture)
__slamallama__@reddit
This isn't a real test of a battery, I can guarantee your battery is cooked. It sounds like they did a load test that came back at 65%, which is also not good. Batteries don't need to be at 0% to be useless.
itchybiscut9273@reddit
Volt meter isn't a real battery test. Did he hold the meter on it when you cranked it? If it's dropping below 10 volts when you turn the key the battery is done.
GeriatricSquid@reddit
Change the battery. Battery tests won’t always find a bad battery but your symptoms are spot on for a dead battery. Especially if the battery is original to the car. Batteries only last 3-5 years and you’re there if it hasn’t been replaced.
lazarinewyvren@reddit
Autozone does not employ techs. They employ cashiers with minimal training.
Amazing-Ass-7891@reddit
That's called a bad battery. It's now 6 years old if original, which puts it firmly into end of life range. You cannot get the lost capacity back. No amount of charging will fix it
1AlertAsparagus@reddit
Loose battery terminal
Global-Structure-539@reddit
Something is draining it. The obvious would be an interior light inadvertantly left on to something deeper
funcentric@reddit
Replace the 12v. They generally are replaced every 5 years ish.
u_siciliano@reddit
Check battery voltage after a long drive. Probably bad battery or not charging properly since alternator seems to run car ok.
Poorly_packaged@reddit
If the battery is fine, it would be a charging system problem like the alternator.
skylinesora@reddit
Wouldn't be the alternator if it doesn't die while driving
Icy-Fortune1910@reddit
A vehicle can run with a crap alternator without dying. The battery will die off while driving and be hard to restart. A weak battery is hard on the alternator, a weak alternator is hard on the battery. It is a bit more nuanced.
D_Angelo_Vickers@reddit
Wrong. It needs a battery. The AutoZone battery test is bullshit.
Hot-Development-9036@reddit
Sounds like either a weak battery or some sort of thing draining the battery, like a faulty ground. I’d bet it’s the battery.
MushroomFondue@reddit
The alternator does a poor job of recharging a battery. It will maintain a charge if driven long enough and frequently enough. If your battery is dead and needs to be jumped, you need to charge it using a battery charger.
Twistygt@reddit
6-7 year old battery bro….
[)
Jamestown123456789@reddit
When was the last time you replaced the battery?
Mizar97@reddit
If it stayed running after being jumped, your alternator is fine. Sounds to me like it's the battery. Tester may say it's good but I would replace it, then if it starts up no problem take the old one in for the core charge.
Aggressive_Ask89144@reddit
What does even 65% even mean? 65% of the battery's CCA? That's pretty close to failure from what I've seen working across the street at Advance. Our machines will pick up on dropped cells or failure even if the voltage is close. Had a Subaru with similar issues the other day even though the battery was reading 12.4 volts off the multimeter. (O'Reilly's has a way better OBD scanner though than our 20 dollar floor unit lol) It's also a 2020 and sounds like the original battery and it's about time. It's been in there 7 years. Your car runs off the alternator while you're driving and it only fails when you park since your car doesn't have the proper stuff to kick it off again.
You can try to charge it, but it's probably not going to do much. A fresh AGM will last about the same time and cost about 260 or 280 after tax and the auto part stores will install it or you can go to Rural King or the classic Jeff Bezos special and order it with a twice as long warranty and pay 175.
Yakker65@reddit
It’s not your charging system as it stays started after you jump it. How old is the battery? It sounds like that could be the problem
dave200204@reddit
It's the battery. It's not holding a charge. The alternator will keep charging the battery while it's running. However you can only recharge a battery so many times before it quits. If that's your original battery I'm guessing it's more than three years old, it's a 2020 car. Three years is all you can expect from a car battery.
Eschewed_Prognostic@reddit
Needs a battery. 65% after a lot of driving is very bad. I bet if you took just the battery after a couple hours, it would be much lower.
If it's the original battery it's definitely time.
TheDude-Esquire@reddit
I have a 2019 Mazda and I’m on my third battery. I’d start there.
Top-Confidence4496@reddit
Battery isn't providing enough cold crank amps. Bring it to your shop and let them know what's going on
rwv2055@reddit
What was the voltage with the engine running? Had it been running for more than 60 seconds? If not, crank it up, and let it idle with the ac off for a few min. When the ac is on, the radiator/condenser fans run. They can draw up to 40 amps. Put a volt meter on and watch the voltage as you try to crank it. What does it go down to?
You need some one who can load test the battery to truly test the battery.
If you drove it for 70 miles, the alternator is most likely fine, and its just a battery. If you can change the battery yourself, Walmart is much cheaper than AutoZone and O'Reilly's. Like more than 50% cheaper.
Aware_Necessary8288@reddit
Check that all your fuses are seated properly Check for blown fuses and replace as needed Replace battery if the above don’t work
Outside of that, you’ve got parasitic draw. A car that new, I’d expect parasitic draw to be from something telecommunications related like the infotainment trying to update over air continuously.
To be honest though, given the specific part of your post saying that even after a 70 mile drive, it won’t start after a short parking period, I’d say with a lot of confidence that it’s either a bad battery or a failing starter.
JosephPapparelli@reddit
If the car is a 2020, you’re due for a battery anyway, plus the fact that all the symptoms point to a battery with a dead cell. You know your charging system is working correctly if she runs fine once started. Get yourself a battery.
aubreysAREhot@reddit
Something could be draining the battery. For example if for whatever reason the inside trunk light stays on although the trunk is closed, that would drain the battery. I know someone who had a kill switch installed in her battery that should would have to flip everytime because the trunk, although jt would lock closed, the mechanism wouldn’t communicate that the trunk was closed and the light would stay on, killing the battery, even if the bulb disconnected.
Check all over your car and make sure nothing is draining it randomly.
Educational-Ad2063@reddit
Original battery? 4 to 5 years is about the life span of today's batteries.
ocabj@reddit
Change the battery.
Calm-Show-9606@reddit
Bad battery or alternator.
skylinesora@reddit
Wouldn't be the alternator if it doesn't die while driving
Calm-Show-9606@reddit
Yes it could, the alternator may only putting out enough to run the car and not also charge the battery. I had that happen. I swore it couldn't be alternator until I put a meter on it . And since voltage regulators are now built into alternator it can be that.
_totalannihilation@reddit
That's a battery replacement all day long.
salvage814@reddit
What I want you to do is unhook the battery jump directly from the terminals then unhook your jump box. Look at the gauges if your battery light is flickering or your gauges go funky. Your alternator is no longer changing your battery. If it isn't your battery has a bad cell.
BeneficialDrink@reddit
Auto zone employees have the computer that hooks up to the car to runs diagnostics. Take it back so they can see what’s coming up wrong. Probably the alternator.
Kdoesntcare@reddit
Look up how to test for a power draw
AngryAlien21@reddit
If it’s the original battery, I’m surprised you’ve gone this long with it. Mazda batteries are junk, and the biggest complaint for these cars
Tangboy50000@reddit
The cold crank amps are what you need to look at, not the charge on the battery. If it’s the factory battery, it’s time to replace it anyway.
Glittering_Bar_9497@reddit
The battery has a second value which measures something equivalent to strength to crank over. I had something similar happen with my minivan granted it has automatic doors and I have a toddler and my gf( god bless her soul) would open and shut side doors and trunk with car off. It sounds to me like a battery issue, they usually only last 3-5 years now( right when warranty expires in my experience). No mechanic just my thoughts on the matter.
Glittering_Bar_9497@reddit
Side note you can use that jumpstart battery for quite some time but it will eventually fail or get harder to start. I went 4 months limping on a jumpstart pack. Lol
New-Swim-8551@reddit
You have a parasitic drain on your battery. To save they put a marginally sized alternator in. Because of the small alternator it wont fully charge a dead battery during a normal drive cycle
You need to charge the battery overnight to get your battery fully charged, then you need to find the parasitic drain
Bud_Bones_69@reddit
Alternator
itchybiscut9273@reddit
Definitely isn't an alternator. Car would be dying when driving if it was
sergioraamos@reddit
I would just replace the battery and see it helps
Themike625@reddit
Just because a battery has voltage doesn’t mean it can carry a load to it when trying to start the car.
Change your battery. They’re relatively cheap. And it is 6-7 years old at this point. If that doesn’t work, find a mechanic to check for voltage draw from the alternator or one of the other computers on it.
Start with the battery.
itchybiscut9273@reddit
Battery % and voltage are only half of what a battery needs. They should have done a load test to check the amps.if a battery is failing it won't have the amps needed to start the car. Take it to a shop and ask them to do a battery load test.
warwolverinewarrior@reddit
Are theconnections on the terminals on the battery super tight? Lose connections can cause that.
Fishtickles@reddit (OP)
Terminal connections are tight
warwolverinewarrior@reddit
Wouldn't hurt tightening them some more
Fishtickles@reddit (OP)
Ill give em another good look. I thought I got them pretty darn tight after I checked for corrosion on the terminals
Smooth_Discussion367@reddit
Might do some research to confirm, but sounds like a battery with a dead cell. A bad ground is causing a break in continuity