A little battery talk

We talked about replacing alternator brushes in another thread and I thought I would add some battery talk to the mix.

You hear a lot of hype and marketing BS about automotive batteries and most of it is just that; hype and BS.

The market for automotive batteries is HUGE and sales often occur at a time when the buyer doesn't have a lot of time to contemplate his/her options (in other words, their battery just died and they need another one right now).
As a result of those market forces, there's a lot opportunity to take advantage of the uninformed consumer.

So, instead of waiting until it rains to buy an umbrella, why not educate yourself a little before the situation becomes a semi-emergency?

The battery stores the electrical power needed to start your vehicle, it provides limited power for the electrical system when the vehicle isn't running and it provides some current to supplement the alternator when the vehicle is running but the alternator output is inadequate to meet short term power needs.

A conventional lead-acid battery is a simple device to convert stored chemical energy into electrical power and the process can be reversed to recharge the battery.

Ratings for automotive batteries:

Voltage - most car and light truck batteries are 12 volt batteries. Enough said there.

Terminal type and location - The terminals can be top post or side post and the location of the positive and negative terminals can be varied. These are largely just physical attributes dealing with the types of battery cable terminals and the length and location of the cables.

The "Group" size of the battery - This is the physical dimensions of the battery case and the orientation of the terminals. Automotive batteries are made in standard sizes known as "Groups" such as Group 24 or Group 27. You generally want the largest size battery that you can fit into the available space. By the way, the first generation Tacoma's will accept a slightly larger battery if you modify the plastic tray under the battery just a little.

Warrantee period - This is one of the bigger scams. While there's a little bit of reality to the ratings concerning how long the battery should last, there's a little exploitation going on there as well. Battery warrantees are pro-rated and by the time most of the batteries fail, the seller has already made his money even if he gives you a little back occasionally. Because a majority of batteries live past their warrantee period and not everyone collects on the ones that don't - the sellers aren't losing a dime.

Cold Cranking Amps - There's a bit of marketing here as well. High cold cranking ratings certainly sell batteries but the figure is a bit misleading. Here's the rating explained:

Cold Cranking Amps [CCA] is the maximum amperage the battery can supply for 30 seconds, at zero degrees Fahrenheit, before the voltage drops below 7.2 Volts.

This is important because the output of a lead acid battery drops as the temperature drops. A battery that puts out 500 amps for 30 seconds at 50 degrees may only put out 300 amps at 0 degrees. So it's good to start with more than you need at warm temps so that you'll still have enough at low temps. We need a minimum output in cold weather to start the engine. AND, it's more difficult to turn the engine over when it's cold plus it can be difficult to get the engine to actually start when it's cold. So a high CCA rating looks good when you're trying to start engines in cold weather. However there's a hitch.
There are diminishing returns on the amount of amps we can actually use. The battery cables and starter can only take advantage of a certain amount of current. Beyond that amount, you gain nothing. In addition to the practical limit on useful current, there's the reduction of durability of the battery itself. Making the plates thinner in order to get more plates in the battery and achieve a higher CCA rating can come at the cost of a shorter life battery.

Reserve Capacity - This is often the true test of a battery.
Reserve capacity is defined as the number of minutes a fully charged 12-volt battery at 80 degrees Fahrenheit can provide 25 amperes at 10.5 volts until the voltage drops below 10.5 volts.

A battery that has a good reserve capacity and enough CCA to meet the worst case scenario is the combination you want. Excessive CCA ratings look good on paper but do little in the real world. Reserve Capacity is a better measure of what we ask of a battery. The ability to produce useful power for long periods of time and still be able to start a cold engine is a real world concern.

BTW, there are only a handful of companies that produce automotive batteries. They are made to different standards and labeled with different brands.

 

Cold weather and dead batteries.

Everyone knows that first really cold morning is when your battery will eventually let you down but it isn't the cold that killed your battery!

We frequently see an old car battery fail in cold temps but it wasn't the cold weather that did your battery in, it was the heat that killed it. The cold weather just exposes that dying battery. Because the output of lead acid batteries drops with temperature and cold engines are harder to turn over, it's those cold mornings when we often see that old battery die but that death actually occurred during the summer!
Heat kills batteries but because they continue to put out useful, albeit reduced, current in 80 and 90 degree weather; we don't see that damage as frequently in the summer. Then the weather turns cold and that old, almost dead battery that was harmed during the summer finally gives up.

SO, if your battery is at that 4-6 year mark AND you live somewhere that gets really hot in the summer- start thinking about the health of that battery in the early fall.

 

What about battery weight? For instance a Everstart Maxx weighs significantly more than a valuepower battery of the same group, and they are both made by the same manufacturer, East Penn. the Valuepower is half the cost but comes with one year warranty instead of 3 yr. Does the weight aka sparseness or abundance of lead plates play a role in lifespan? Maybe these are the same battery now.. the CCA rating is the same!

maxx - 44.4 lbs
Valuepower - unknown (says 44.4oz...)

https://www.walmart.com/ip/EverStart-Maxx-Lead-Acid-Automotive-Battery-Group-24F/28275657

https://www.walmart.com/ip/ValuePow...75035&wl11=online&wl12=47308797&wl13=&veh=sem

 

Battery Terminals and Cables.

The best battery in the world will do you no good if you can't get that current to the starter and the rest of the vehicle.
AND
You can't CHARGE that battery effectively if you can't get the current from the alternator back into the battery.

Clean and tight battery terminals are KEY to getting the best performance out of your battery. Clean those posts. Clean those terminal ends where they contact the battery posts and snug them up well. After they are clean and tight, seal them with a good battery terminal sealer. If they've been protected with grease to seal them, you either have to continue using grease OR completely degrease them and seal them with a spray on sealant.

If you need to replace cables, keep them as short as possible and use the largest gauge cable you can get away with. Clean and seal both ends.

 

Curious as to what you meant by slight modification to the tray. I’d like to move up from a 24 to a 27 series.

 

You hit the nail on the head ! The only way to reduce the cost of that cheaper battery is to make it with either fewer plates or thinner plates or both. Look at the specs for those two batteries and see if they are the same.
There are NO free lunches. They have to compromise somewhere in order to hit a price point.

 

There's a plastic tray under the battery that has a small lip around the perimeter. In order to use that plastic tray (and I think you should continue to use it) cut the lip off of the short edges so that the battery can hang over those ends.

I'm not certain a group 27 will fit but a group 48 (roughly 12"x8"x7") will fit and the factory hold down will work. Some people report the group 27 will fit.

 

Well the Walmart website says the valuepower weighs 44.4OZ so I'm going to assume that their website is not accurate. Most of the places I've checked say they weigh between 3-5 lbs less than the Maxx batteries

 

I see a difference in CCA, so they may have simply reduced the number of plates.

 

I was always very tempted to replace led-acid battery with custom built battery pack of DeWalt's A123 cells. Each 2.2Ah cell can deliver up to 100A. So battery of 4s10p would be enough to start the truck in any temperature. Life span of these cells is also good (much better than traditional led-acid). And they weight next to nothing. Just high cost is limiting factor.

 

If I recall when I was looking at specs, the only difference between 24 and 27 was the length.

 

That could be true I don't recall.

 

I would suggest a odyssey or northstar or a auto parts store agm in that order if budget allows. As for lead acid I would go with a everlast. I find them at costco and they have the best warranty of all!

Edit: not everlast, its interstate batteries

 

NorthStar AGM it’s true. Just a bit longer

 

I would never buy a battery based on the warrantee. I buy batteries based on performance of the battery. Unless the battery dies two weeks after I buy it, the warrantee is worthless. When the battery dies 47 months into its 48 month warrantee, they pro-rate it and give you $0.05. After that you still need a new battery.

As a practical matter, I buy all of my batteries from a local shop that specializes in batteries and he puts his own logo on plain black batteries that are commercial batteries from one of the major makers. I've never needed the warrantee on any of the batteries I purchased from him and they've all out lasted their predicted lifespan.

 

I wouldn't buy one based on warranty either. I don't remember saying that. Odyssey and northstar batteries are very good batteries and put out much more than rated.
Both of my odyssey pc1750 batteries are rated at 950cca and for like year and a half they would show a error most of the time on my solar ba9 tester meaning it was testing over 1200cca. I thought it was defective but then I tried a higher capacity model and saw what it was
Deka ( spelling) makes the auto part stores agm batteries. They are good but not as good at the other two.
The everlast(everstart, or some shit) batteries last a very long time as well. The warranty on those is return it whenever you feel like it for a full refund (when bought at costco) and buy a new one with the money they gave you back then your warranty (I think 3 yrs) starts over again.

 

If I get 2 years out of a battery I am happy !!

To many times over the last 30 years I fell pray to the I need a battery now .

I am lucky to have East Penn manufacturing about 20 miles away and a Interstate distributor about 10 miles so those are my two brands of choice

Interesting I was told by my Interstate salesperson " I can sell you a AGM battery but I think for the cost they are a waste of money"

 

Take a breath. I didn't claim you said anything. You commented on a warrantee and I responded that I wouldn't use the existence of a warrantee as a purchasing criteria.

You wrote, "I find them at costco and they have the best warranty of all!'

and I wrote, "I would never buy a battery based on the warrantee"

You made a comment about a warrantee and I made a comment about a warrantee.

 

Sorry about that
We're all here to help each other

 

Is it the weather or the way it is used killing them? 2 years is way to short. I'm getting at least 6-8 years of battery with normal use (no winches, fridges, left lights on etc.). And that was under California sun and now cold winters in Poland (summer in Poland is now almost as hot as California, plus rain minus smoke). Or maybe you need to change brand of your battery.

All batteries I was buying were of the shelf in O’Reilly Auto Parts (used to be Kragen ten years ago). The one I have now (I paid less than 100 dollars for it back in 2012) is "Super Start Premium 24R72J" that has 600 CCA with sticker 1/12. Last winter when we had close to 0F in the morning I heard it workeong a bit hard starting the truck after spending the night outside, so I guess this winter it will be time to replace it again (after 7 years). That also confirms the "Warranty Scam".