Have you checked the alternator output while driving? Get the Torque app for your phone and buy one of the ELM27 OBD2 adapters Then you can check the output voltage . If its under about 13.0, alternator may need to be replaced.

 

I guess logically a large capacity battery will hold more charge longer. Not sure if extra cracking amps will make a different though but one follows the other .. bigger = more Cranking amps. Granted you newer mazda have more gadgets to draw when off. Do the keyless feature consume more battery because they are scanning for the fobs. Would deactivating the Fob (pull battery out) help or is there a way to deactivate it completely.

 

Faraday cage for your keys if they are most convenient within range of the car?
That said, a $30 battery tender would appear to be the best course of action instead of $$$ batteries.

I always worry about the draw from my dashcam (capacitor instead of actual battery) that we keep running for hours (sometimes days at a time by accident) but luckily we have not had any issues on our 6 year old, 120,000km OEM battery). Due to winter, I do charge it fully in the fall, and once more in the middle of winter just to prolong it. Lithium booster pack lives in the car (our daily), so I'm confident in my contingencies.

RE: replacements, unless lithium (you seem to be a good candidate for ultra lightweight batteries), I love Kirkland's 8-year warranties.

 

Same here ...Lithium booster lives in my car too..but i do bring it in when super cold>

 

Mazdas must be fully locked or the batteries go flat. My wife went from parking in the street locked to parking in our garage unlocked and the battery started going flat within days. Lock the car in the garage and everything's fine.

 

That may have been related to key fob proximity in the garage. Draining battery as the car kept searching and getting a response from the fob.

My battery doesn't die, but the car struggles starting up sometimes. Even after replacing the starter. Like the battery isn't recharging fast enough or something.

That's why I'm considering the Optima Yellowtop. It's recharge rate is supposed to be quick, though it has a lower CCA than some batteries.

The LiFePO4 batteries seem cool too. Although they are expensive and require a backup charger.
CK

 

My car sits sometimes for days unlocked with no problems....even covered with snow at 10°F.
2016, still has OEM battery.

 

Was Antigravity battery mentioned before as an alternative

AUTOMOTIVE LITHIUM BATTERIES

Our Lightweight Lithium Car Batteries have our new WIRELESS RE-START technology and FULL Battery Management System (BMS) for safest longest life.

antigravitybatteries.com

 

Cool.. but way too expensive. With all of the extra gear needed it would cost over $1k.

I guess the added life of the battery saves some $ over time, but that's still a big pill to swallow.
CK

 

true
I was lucky enough to find the shorai battery for $150 used

 

Get the X2 from batteries plus. 5 year replacement warranty and I think 840cca. I bought mine 3 years ago and haven't had a lick of problems with it.

 

X2Power Premium AGM Battery for 2014 Mazda 3 L4 2.5L 525CCA Canada/Cold Climate/Sedan Car and Truck - SLI35AGMDP at Batteries Plus Bulbs

X2Power group 35 AGM replacement battery designed for low maintenance and dependable engine starting power. Perfect replacement battery for Mazda, Nissan and more

www.batteriesplus.com

 

My 2018 SGT - I-eloop isn't charging up and my OEM battery appears to be failing.

Updated:
Replaced with Optima D35 AGM battery and everything works great

 

I had the same problem with my 2015 Mazda 3 hatchback. The past 2 years after 3rd day, I had to jump-start. I read about the dome light turned off or something. So I checked it out, turning the dome light off and shorting time delay on the light. But nothing, until a month ago when I turned off the trunk light. I noticed on the 3rd day it started up easy. Now I'm on a week parked & still turns on easy. I'll try to update if any changes. Hope it works for you guys.

 

I had the same problem with my 2015 Mazda 3 hatchback. The past 2 years after 3rd day, I had to jump-start. I read about the dome light turned off or something. So I checked it out, turning the dome light off and shorting time delay on the light. But nothing, until a month ago when I turned off the truck light. I noticed on the 3rd day it started up easy. Now I'm on a week parked & still turns on easy. I'll try to update if any changes. Hope it works for you guys.

I'm going to assume that you mean trunk light since I don't know what a "truck light" is.
Although what you've found is great, I think it's symptoms of a greater issue. You have evidence that the light does not turn off as it should when you close the trunk and leaving it switched off is just fine.
HOWEVER....a small light left on overnight should not drain your battery. That tells us that either the battery is losing capacity in a big way or the alternator is not charging it as it should.
I would start with load testing the battery. Better to replace it now than to get stuck somewhere looking for a boost.

 

I've checked the light with the lid closed & switch on in the trunk the light is off. So it's working the way it should. Why is my battery not dead like it was before after the 3rd day? The only thing that comes to mind is bad wiring or as you said, the alternator. Thanks zero_gravity

 

many factors, temperature has a big effect. length of drive as CK has mentioned. even with a long drive, the alternator does not charge the battery fully. my experience is about 70% give or take.

now back to the matter at hand. you have no way of knowing the condition of the battery without testing. many parts stores will do this for free. load testers are cheap tools. you can measure the voltage to see if it is being charged, but that is also a sign of a dying battery. diagnosis is a process of elimination. we take all the possibilities and eliminate them one by one until there is only one left. first and easiest one is load test the battery. after that you can start looking into more complex things like alternator.

as a side note i'd clean the terminals....worth a shot.

 

The length between driving the car and the length of the drives make a difference. Their is some draw on the battery while parked from the cars systems. Longer drives allow the battery to fully charge.. short drives do not.

 

Since I switched to an AMG battery.. startups have been much better. They recharge at a faster rate and have a higher cold cranking amp rating.

 

Same here, my northstar is still running happy 6 years later.

 

2014 Mazda3 has this problem in a severe way. I've had about 8 batteries so far. New battery May 2022 dead by October 2023. New battery in October 2023 is dead now after frequent drives, no sign of alternator issues. Neither the dealer or my (excellent) mechanic could find anything. I'm in a condo, can't use a trickle charger. Investing in a portable charger. Won't buy a Mazda again.

 

It's nothing wrong with mazda, specifically just the design tied to QA happens to have a smaller CCA battery. Most manufactures do this because Quality assurance process is typically 1 year. Trick is buying an oversized battery or buying something that nearly doubles the stock CCA and you should be fine. If you are doing a stock sized battery make sure you get a battery insulation kit as they don't like getting down to freezing or up to higher temps. An insulation kit will help protect the battery some areas of the country will come with one. Some will not.

 

The stock battery insulation from Mazda fit my Group 35 Everstart AMG battery. I bought a new one from an online dealer, as the original got lost at some point. I think it was $30 or so..

 

I fully endorse Odyssey AGM batteries.

What about Optima? Optima AGM batteries have fallen from their high position in the pantheon of automotive products, based on my recent experience. Once widely-praised, Optima batteries no longer appear to perform as well or as long as expected.

The Optima batteries I installed in our former '07 Nissan Quest and '07 Mazda 3 endured for several years, and were still performing well when traded away. The most recent batteries installed in our former '16 Nissan Rogue and current '18 Mazda 3 began showing weak behavior a mere two years into their lives, running down after less than a month of being parked. This became evident when we were away for several weeks in 2021. After returning home, I had to jump-start the cars a few times, and began keeping the Mazda on a Battery Tender until I could drive it at least once per week.

We traded away one Optima battery with the Rogue in late 2021, but the one in the Mazda continued, cranking slowly every time. Before I needed to put it on the tender all winter, in went a new Odyssey AGM. It's heavy and expensive, and a year later, still cranks reliably between infrequent drives (I haven't commuted regularly in nearly four years). Look at those brassy terminals. 😁

 

View attachment 292998 View attachment 292999

I fully endorse Odyssey AGM batteries.

What about Optima? Optima AGM batteries have fallen from their high position in the pantheon of automotive products, based on my recent experience. Once widely-praised, Optima batteries no longer appear to perform as well or as long as expected.

The Optima batteries I installed in our former '07 Nissan Quest and '07 Mazda 3 endured for several years, and were still performing well when traded away. The most recent batteries installed in our former '16 Nissan Rogue and current '18 Mazda 3 began showing weak behavior a mere two years into their lives, running down after less than a month of being parked. This became evident when we were away for several weeks in 2021. After returning home, I had to jump-start the cars a few times, and began keeping the Mazda on a Battery Tender until I could drive it at least once per week.

We traded away one Optima battery with the Rogue in late 2021, but the one in the Mazda continued, cranking slowly every time. Before I needed to put it on the tender all winter, in went a new Odyssey AGM. It's heavy and expensive, and a year later, still cranks reliably between infrequent drives (I haven't commuted regularly in nearly four years). Look at those brassy terminals. 😁

They stole(bought Northstar) who makes their batteries now. The extreme series has the gold contacts like the Northstar. My Northstar is still going 6 years later where the factory had issues within 3 years and it was the 900 dollar special battery for the hybrids we had in 2014.

 

Odyssey is a good choice but it costs double the price of Walmart's Everstart battery.

Avoid Optima and Interstate.. very high fail rates due to changes in quality and manufacturing over the last several years - per many customers reviews and a few articles I read.

 

Odyssey is a good choice but it costs double the price of Walmart's Everstart battery.

Hard to argue with only $180 for a decent AGM battery with good warranty from a local superstore. That's a good buy. YMMV, of course, depending on which manufacturer made your particular model. Could have been East Penn or Clarios (acquired from JCI along with Optima).

 

I actually whhen back to using a regular oem sized battery from Honda - same CCA but smaller size.
The 4LB lithium is being stored for summer use only

 

I did not had issues with my battery. I bought my 2016 used with a 01/2019 date battery and still runs perfectly 5 years later. Now the SOH is 84% so still it has life left. However, the battery is an oversized 725 cca and size 24F which fits fine.

Maybe a bigger battery is the solution to have a car parked for days without discharging.

 

my idle curiosity... for those that have battery drain issues, do you have the i-eloop feature? getting an AGM is great if that's your thing, but i don't have the need for it here. i looked and they're almost double the cost of a standard lead acid here. i get the cheap everstart batteries from walmart....and yes they seem to last. starts just fine in the cold and i have no issues with battery drain if i leave it in the garage for several days or even a week. it's a non issue here so makes it hard to justify spending more for a better battery.

but yet many are having glitches due to their batteries....so what's the root cause here? seems silly to be 'fixing' it with a bigger battery.

 

Yep, once I went to the Northstar those issues went away though.

 

Today's cars have many advanced features that require 12VDC energy to keep them active, even when parked. So, if the cars are not driven enough to allow the engine-driven alternator to keep the battery properly charged, the battery can drain down and cause problems.

I ran into this problem during the recent pandemic, Before the pandemic, I used to drive my 2015 Mazda3 regularly on the highway and experienced no recurring battery problems. In contrast, because of the pandemic, my driving habits have been curtailed significantly. I now can go for a week or more without having to start the car. As a result, I found it hard to keep the battery properly charged due to the parasitic drain that occurs when the car is not driven.

So, I had a choice: drive the car more and pay for more very expensive gasoline; keep the battery charged by keeping it plugged into a charger; or install a battery-disconnect switch which isolates the battery from any drain from the car.

I chose the latter. I have found that a $10 battery disconnect switch allows my battery to maintain a fully charged battery with a voltage level of around 12.7 volts even when parked undriven for a month or so.

The only disadvantages I have found is that I have to lift the hood to reconnect and disconnect the battery, and if I want their services, I have to reset the clock and the preselected radio stations. Even so, I'm happy with my choice.

 

I was having the problem of a dead battery if the car sat unused for about two weeks. I bought a battery boost starter for about $140 and that helped when it was dead. I was sure there was a phantom draw but Mazda couldn't find one. The battery was new. After reading about others with the problem I changed settings on the car (no effect) then removed a USB cable that I used for my phone and removed a USB plug that had a blue light on it and went into my cig lighter. After that the car sat unused for about 6 weeks and then started right up. I think the problem is solved. This is a 2018 Mazda 3 with the standard battery. The problem became apparent after I stopped using it a a daily driver and would let it sit for 1,2,3 weeks.

 

The USB ports and 12V outlet are always hot on our cars. Unusual, but I rather like it. But yes this is a phantom draw if you leave something plugged in.

 

 

That's a known issue but theres more to it than that. Stock Mazda batteries recharge rate is to slow - AGM batteries are a big help due to faster recharge rates when driving and higher CCA ratings.