Car Battery Questions

[oc_in_fw]

12.6 V is considered marginal, 13.2 is closer to normal for a good battery.

 

[njpaddy]

Why Electric Cars Don’t Have Better Batteries

Specific to electric cars, but I feel it pertains to all battery technology.

Thankfully, at my age, I'll be dead before I have to drive an electric car. I'll be lucky (more likely unlucky) to make it to the end of the world in 12 years.

 

[njpaddy]

I received the Battery Tender Plus yesterday. I also ordered their 25' extension cord. Since I have no garage, I left the unit in the house and ran their thin extension out a window to the battery. I only let it run for 6 hours to make sure it was working and doing something. Battery reading was 12.0 when I hooked it up. It was dark and I didn't take a reading when I disconnected it. This morning the reading was 12.5 and the car started right up with temps in the low 20's. I'll drive the car a bit today and hook the charger back up in a day or two and max the battery out. As of right now, it looks like a good solution to my problem.

Thanks to everyone for their comments. It's always helpful to find members who know more than me on any given topic.

 

[machinisttx]

For the third year in a row, the 490cca Honda battery in my 2004 Accord is giving me problems. Last year the Honda dealer replaced (for free) a 1 year old battery they said was bad and this year that battery again failing to start. It could be partly my fault as the car is only driven a couple times a week, but that's been the case for 15 years (it's only got 50k since 2004). Very cold days and nights the past 3 years have been killing even new Honda batteries.

Yesterday I let the car run in my driveway for 1.5 hours at 2k rpm after I jumped it, and my battery tester and multimeter now read 12.1-12.2. The Solar tester says it still needs to be charged. Is there a way to get that up to full charge without pulling the battery and having an auto parts store charge it or buying a trickle charger (I have no garage)? Will running it in the driveway or a long trip do it? The multimeter does not show a parasitic draw and reads 14.3 when running which I assume means the alternator is charging.

Once I get past February it should be fine the rest of the year, but I am almost at the point of paying to replace the 490 cca with a 640 cca battery from an auto parts store. As far as I can tell it's a Series 35 battery.

Ok, so lets start with the basics. You've checked the battery voltage without the vehicle running, and with the vehicle at idle. You're seeing short battery life. I'm inclined to ask if you checked the voltage with the engine above idle? I'm also curious what the temperatures actually are. Also, do you have a battery insulator or heater? https://www.amazon.com/Kats-22200-W...&s=gateway&sprefix=battery+bla,aps,206&sr=8-5
https://www.amazon.com/Zerostart-34...ttery+heater&qid=1549813823&s=gateway&sr=8-14
https://www.amazon.com/AOPEC-Batter...s=gateway&sprefix=battery+bla,aps,206&sr=8-12

Those may or may not be applicable to your battery size, I don't know. I just put them in as examples. A cold battery can't supply as much energy, and one that's already somewhat discharged is disadvantaged even further....and the existing OEM battery size is likely only marginally adequate to start with. Personally, I always run the highest CCA battery I can get...and I live in Texas where it isn't all that cold. They last longer....greater capacity means that the battery doesn't work as hard to supply the necessary energy.

So, back to the battery itself. The voltage you listed with the engine not running is too low. That battery is probably already a goner, but you might try a charger that also desulfates the battery as a part of the charge cycle. That might get you another season or two IF you really take care of the battery from this point on. The voltage you listed with the engine running is within the range of where it should be. If it wasn't charging, or charging enough, the voltage would be the same as when it wasn't running. Also, contrary to what others have said, your alternator is capable of charging at idle and most definitely capable of charging at 2k engine rpm. This isn't the 1970's and alternator technology has improved significantly. That said, the alternator in a honda in not going to hold up to trying to charge a bad battery for very long.

I think you need to upgrade the battery, along with either installing a battery disconnect or manually disconnecting the battery cables when the vehicle won't be used. Honestly, you might as well take the battery inside with you since it sounds like the vehicle doesn't get much use anyway. Either way, a high quality float charger/maintainer is mandatory if you want any battery life.

 

[njpaddy]

So, back to the battery itself. The voltage you listed with the engine not running is too low. That battery is probably already a goner....

I think you need to upgrade the battery

Thanks, I agree. The best the Battery Tender can do before shutting off is 12.7, but as soon as I turn on the headlights for a few minutes to reduce the 3-10 surface charge, it drops to 12.1. Also after fully charging on the Battery Tender, the starting amps still drop to 9.1. But for now it starts and sometime before next fall I'll spring for a better battery than a Honda.

 

[shavefan]

A cold battery can't supply as much energy, and one that's already somewhat discharged is disadvantaged even further....and the existing OEM battery size is likely only marginally adequate to start with. Personally, I always run the highest CCA battery I can get...and I live in Texas where it isn't all that cold. They last longer....greater capacity means that the battery doesn't work as hard to supply the necessary energy.

Also, contrary to what others have said, your alternator is capable of charging at idle and most definitely capable of charging at 2k engine rpm. This isn't the 1970's and alternator technology has improved significantly. That said, the alternator in a honda in not going to hold up to trying to charge a bad battery for very long.

Your statement is not contrary. Sure an alternator is capable of charging a low battery but if called upon to charge a battery often, the alternators life is shortened. They are not meant to charge low batteries.

There's a lot of emphasis on cold weather being detrimental to batteries but heat is just as bad. Higher temps actually increase self discharge of the battery. Not much of an issue in the northern climates but sure is down here in TX.

 

[Daiķon]

I agree that you might want to check into your alternator. Even a Honda can have some trouble after 15 years.

Low miles and cold weather add up to a tough time for a battery, though, even with a good alternator. An alternative is to get a portable battery booster/jump starter to get you though the cold weather. There are some pretty good ones out there for around $40-75.

+1 on the alternator check

 

[machinisttx]

Your statement is not contrary.

I have no idea what this is supposed to mean?

Sure an alternator is capable of charging a low battery but if called upon to charge a battery often, the alternators life is shortened. They are not meant to charge low batteries.

There's a lot of emphasis on cold weather being detrimental to batteries but heat is just as bad. Higher temps actually increase self discharge of the battery. Not much of an issue in the northern climates but sure is down here in TX.

It's really no different than having the wipers, heater/defroster, radio, headlights, etc. on all at the same time. I don't suggest that anyone do that frequently, but it does happen.....and I did say that I don't think a honda alternator is going to last very long charging a bad battery.

Heat does kill batteries....but overcharging a hot battery is certain to kill it. This is one reason automakers now install battery temperature sensors.

 

[Mr. Bonney]

Car batteries are among the worst as far as quality is concerned. I used to be able to goes YEARS without even thinking of the battery. Now it's every 2-3 years like clockwork, and usually you get stranded or it's not a good time financially. Makes having AAA a must.

 

[machinisttx]

Are you buying the cheapest battery you can get? If so, that's the problem. I still get 5-6 years out of a battery at least, barring random defects.

"Maintenance free" with flooded lead-acid batteries really means "We've made it so that you can't add water to replace what is lost to off gassing during the normal charge/discharge process". True sealed lead acid batteries or gel cell batteries aren't usually what's available at the local discount autoparts chain store. If you're willing to drop the extra $$$, then ODYSSEY Battery - Official Manufacturer's Site is top of the line and many folks still claim they get 8-10 years out of them. I wouldn't consider Optima...the last time I did some serious checking they were having a lot of quality problems. That said, they may have resolved the issue.