12v car battery charger recommendations?

[Mikej]

Beleive it or not Harborfreight has a battery charger that does pretty good.

4Amp Fully Automatic Microprocessor-Controlled Battery Charger/Maintainer

Amazing deals on this 4Amp 12V High Freq Battery Charger/Maintainer at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

I don't go there normally but it came recommended by someone who used and abused it. I bought one, its been fine for a couple years now. Lives outside on the back porch.

Anyone reading the above, be aware that a 4 amp charger is a little under the output needed to charge AGM, GEL and cycling batteries, properly. 6-10 amps, and 14-14.2 volts is needed to charge cycling batteries. And get full life from them. You can get by charging at lower voltage/amps, but you end up with a bad battery prematurely.

 

[powersbj]

Anyone reading the above, be aware that a 4 amp charger is a little under the output needed to charge AGM, GEL and cycling batteries, properly. 6-10 amps, and 14-14.2 volts is needed to charge cycling batteries. And get full life from them. You can get by charging at lower voltage/amps, but you end up with a bad battery prematurely.

Thanks for the educational moment, I had no idea.

 

[Mikej]

Discharging a vehicle battery deeply will damage it. I've seen car batteries basically become useless after the owner left their lights on 2-3 times.

I am not talking about a discharge where the battery won't start the car but the starter relay clicks and the dome light comes on dimly.

I am talking about where the voltage is below 8-10 volts.

Why You Shouldn't Let Your Car Battery Die

Batteries might be made to die, but there's a difference between a dead battery and a battery that actually has to be replaced.

www.lifewire.com

Car batteries are not made to be so deeply discharged. They are not like RV batteries or solar power bank batteries or trolling motor batteries <- examples of "deep cycle" batteries. Car batteries made to provide high amperage output in a short time, for starting the car, and then the alternator takes over providing the power to run the car.

If a vehicle has a high quality oversized battery, then it may survive more or even deeper discharge cycles, but eventually those cycles will damage it beyond the point where it can recover, and/or you may not notice it as soon.

This is part of what I used to do professionally for a living, it is not just something I heard or read about - I actually have two degrees in this domain.

Most daily driver vehicles today come with the minimum quality/size battery and cables that the manufacturer can get away with - that will start the vehicle when new, in good tune and under warranty. About 3-4 years down the road, the battery nears its end of life, and the cables being minimal diameter with poor quality (equaling higher resistance and wasted power going into heat), one or two cold winters or one or two times the driver leaves the lights on, and the battery will be so damaged that the battery will not hold a charge for long, if it holds it at all.

This is where car manufacturers skimp and save a few dollars - over thousands of cars it makes a nice bonus check for the executives whose idea this was.

On top of that, the fact that a lot of cars today have systems in them that are constantly drawing a little power from the battery even when it sits off, and batteries do not last as long as they should.

Plus, car owners who cheap out and buy the least expensive battery they can, maybe even undersized...

I try to buy decent quality, and if it will fit, an oversized battery with a higher rating (e.g., for my trucks). I often will replace the cables with high quality larger diameter welding cables - you would be surprised how much faster the starter turns over with those cables - think of them as like a water hose; the larger the hose the more water can pass thru with lower pressure. Electricity is the same way - smaller cables have higher resistance, larger cables less resistance.

The quality of the cable makes a difference too - braided copper wire is superior to copper clad or even aluminum wire - that is why I use welding cables (a domain where having the most amperage over a longer distance makes a difference in the quality of the weld) for battery cables - same goes for winch power cables.

I did not say it won't cause damage. I said it won't kill it as long as it doesn't sit in a discharged state for an extended period of time. I don't know how we could determine how much damage would be caused by a single complete discharge? Negligible? Yes, cycling batteries have different plate thicknesses compared to starting batteries. But even cycling batteries can be harmed by complete discharge, with the same caveat as starting batteries.

I buy the cheapest battery I can. Who wouldn't? The key is the warrantee, cranking amp/cold cranking amps. Is it still only three flooded lead/acid battery manufacturers in the U.S.? O'Reilly's/Auto Zone, Napa, Costco etc are just getting batteries with their names on them from the same few company's. Those parts houses are selling the same batteries you find at Costco/Bimart for a lot more money.

I have a couple of Optima batteries in a couple of hot rods and my Deltran smart chargers were not recommended. I purchased an Optima Digital 400 and it works for the AGM batteries as well as the standard 12v car/bike batteries.

A company recommending only THEIR charger should be used? On THEIR batteries? Go figure!

The heretic and Mike J have it down. BTW, Mike, I too have a boat. I have both the deep cycle and the standard battery. The regular battery needs high amps to WHAM + crank it whereas the trolling motor needs long regular output (deep cycle). A single dual battery tender has been connected to both for 7 years now. Both still doing fine although it's been darned cold. I see there is a 4 bank unit as well for boats.

These guys don'T even list it. https://outdoorsinformed.com/2-bank-battery-charger/

https://www.amazon.com/BATTERY-022-...ds=battery+tender+dual&qid=1613614118&sr=8-39

Edited, 7 years the Battery Tender has been working continuously with the same 2 batteries.

Actually a starting battery will respond to a trickle charger, or lower amp output to charge from a low state due to the thinner plates. A starting battery has many thin plates to provide that "WHAM" of high amperage for the starter motor. The starter can draw up to 250 amps after all. After the motor starts the alternator replaces the voltage quickly to the many thin plates in a starting battery. The cycling battery has fewer, thicker plates. That allows it to provide less amperage for a longer period of time. Those thicker plate need higher amperage and voltage to force the plates to go back to a charged state. That's where I ran into a problem. I found that the ol' Schumacher was only giving 10.5 volts at the 10 amp setting. That's good enough to bring the dead car battery back enough to start, and have the cars system put the proper charge on it.

I've found that even though I very seldom discharge my deep cycle any more than 30%, and always chare within, say 48 hours, after seven years or so they still go bad. You might want to have load and/or the specific Gravity checked on your deep cycle.

 

[Mikej]

For those that want to know a better explanation of the discussion at hand....

BatteryStuff Articles | The Lead Acid Battery Explained

BatteryStuff Knowledge Base Article explaining how a standard lead acid battery works. What is electrolyte? How do you charge a battery? Answers to these and more in the following article.

www.batterystuff.com

 

[johnny bob]

A company recommending only THEIR charger should be used? On THEIR batteries? Go figure!

Mikej I am not computer knowledgeable enough to attach a link so... Check out "the difference between VRDL batteries and flooded cell" to find out what the different requirements for charging different types of batteries would be. There are several makers of suitable chargers for both types of batteries and the charger I chose will work on either type. The Deltran smart charger Plus has different specifications than the basic Deltran smart charger. My chargers are the plus but I prefer the Optima digital 400 due to the light display as it diagnosis the state of charge and charges accordingly. So different types of batteries have different charging requirements and there are multiple manufacturers with suitable chargers. YMMV.

 

[Tony617]

One my old Subarus years ago I was driving at night and the headlights were getting dimmer and dimmer. I was going to the supermarket and when I got back in my car it wouldn't start and battery light was on. I called AAA to see if they could tow me home but the wait time was over 6 hours.

I let the car cool down for a while and turned off everything as was able to get it started and drove 6 miles to my home. I bought a new alternator and replaced it the next day. Those pesky Subarus you can leave the headlights on and they go off automatically when you turn the engine off.

 

[Mikej]

Mikej I am not computer knowledgeable enough to attach a link so... Check out "the difference between VRDL batteries and flooded cell" to find out what the different requirements for charging different types of batteries would be. There are several makers of suitable chargers for both types of batteries and the charger I chose will work on either type. The Deltran smart charger Plus has different specifications than the basic Deltran smart charger. My chargers are the plus but I prefer the Optima digital 400 due to the light display as it diagnosis the state of charge and charges accordingly. So different types of batteries have different charging requirements and there are multiple manufacturers with suitable chargers. YMMV.

That's what I've been saying. Different style batteries have slightly different charging requirements. Those requirements can be met by charges of other brands beside the battery brands charger. It's like AC Delco spark plugs should only be used in our Chevrolet vehicles.

 

[johnny bob]

I had a

That's what I've been saying. Different style batteries have slightly different charging requirements. Those requirements can be met by charges of other brands beside the battery brands charger. It's like AC Delco spark plugs should only be used in our Chevrolet vehicles.

Quite true. I personally have had the best luck using factory recommended products. I use Honda oil in my Honda dirt bikes, Yamalube in my Yammie, Kawasaki in my jet ski, Harley oil in my Harley, Stihl oil in my Stihl chainsaw. My equipment lasts with minimal wear and good performance. In the past I used Klotz Super Techniplate oil in my racing 2 smoke Bultaco's, Hooski's, etc as it mixed with gas or alcohol. It did not work very well in the chainsaw or lawn equipment although it did smell good. I did pay a premium for my AC Delco plugs for my Corvette. One of only 2 GM products I have owned in 62 years as they were factory recommended. I did have AC Delco sparking plugs in my worn out $50 144ci 6 cyl 1960 Ford Falcon. It had many, many miles of neglect when I got it. The engine was covered with oily grime and the plug wires may have been original wires. It ran rough and one night while I had the hood up and engine running I saw the wires arcing to the fuel line and everywhere it could seek a ground. The plug wire boots were arcing around each plug to the the recess in the head. It was quite a light show. I replaced the wires and plugs with Motorcraft products and it ran quite well all things considered. That time and the 2 GM cars are the only experience I have had with the "AC Delco fire ring spark plugs". I do consider factory recommendation to be a good guideline. YMMV.

 

[Flopsweat]

I had a

Quite true. I have had the best luck using factory recommended products. I use Honda oil in my Honda dirt bikes, Yamalube in my Yammie, Kawasaki in my jet ski, Sthil oil in my Sthil chainsaw. For e e

Ah, but where do you buy your Girl Scout Cookies?

 

[johnny bob]

Ah, but where do you buy your Girl Scout Cookies?

Thanks. I didn't get the connection until now. I did chip a tooth on a Tombstone pizza.

 

[Flopsweat]

Thanks. I didn't get the connection until now. I did chip a tooth on a Tombstone pizza.

It's the little huff at the end from Wednesday that really sells it.

 

[ilikegunspdx]

I think I just blew up my trusty old battery charger earlier tonight. I've been in the market for a new one; however, not impressed with what the usual scumbags have to offer.

What are you using, and how do you like it? And where can I buy one...

-Robert

FYI here is a pretty good description of what the ctek smart charger does (the text in the link I mean, the video is pretty crappy imo). Ctek is the brand sold by higher end cars manufacturers such as cadillac, corvette, porsche, Mercedes, bmw, etc. fwiw

The 8 Stages of a CTEK Battery Charger | The Streetside Garage

Having a CTEK Battery Charger means you have 8 stages of charging success. Call StreetSideAuto at 1-877-787-8989 for the best price.

blog.streetsideauto.com

 

[johnny bob]

FYI here is a pretty good description of what the ctek smart charger does (the text in the link I mean, the video is pretty crappy imo). Ctek is the brand sold by higher end cars manufacturers such as cadillac, corvette, porsche, Mercedes, bmw, etc. fwiw

The 8 Stages of a CTEK Battery Charger | The Streetside Garage

Having a CTEK Battery Charger means you have 8 stages of charging success. Call StreetSideAuto at 1-877-787-8989 for the best price.

blog.streetsideauto.com

If I didn't have chargers that meet my needs at this time I think I would consider one of these as the latest in battery technology.

 

[Mikej]

FYI here is a pretty good description of what the ctek smart charger does (the text in the link I mean, the video is pretty crappy imo). Ctek is the brand sold by higher end cars manufacturers such as cadillac, corvette, porsche, Mercedes, bmw, etc. fwiw

The 8 Stages of a CTEK Battery Charger | The Streetside Garage

Having a CTEK Battery Charger means you have 8 stages of charging success. Call StreetSideAuto at 1-877-787-8989 for the best price.

blog.streetsideauto.com

Well heck yeah! Anything that costs twice, or three times as much as the other, is absolutely twice or three time better, yeah?

 

[Flopsweat]

Well heck yeah! Anything that costs twice, or three times as much as the other, is absolutely twice or three time better, yeah?

Well I know wine works like that.

 

[Mikej]

Well I know wine works like that.

Not to me brother! Wine is for cooking, the cheaper the better too. Except, a late harvest Riesling possibly.

 

[The Heretic]

This guy does good tests:

But he did not test chargers

Watching his vids, he covers the name of his charger - but I believe it is a Battery Tender. He uses a slow charger though - less than one amp.

 

[Flopsweat]

This guy does good tests:

But he did not test chargers

Watching his vids, he covers the name of his charger - but I believe it is a Battery Tender. He uses a slow charger though - less than one amp.

I've watched a lot of his videos and I like his methodology.

 

[The Heretic]

I've watched a lot of his videos and I like his methodology.

Yes - much better than the unboxing vids, or the ones where someone does a simple "smoke test".

I have to wonder how he can afford to purchase all of this equipment and take the time to test the stuff he does. I assume he makes $ from the advertising and maybe sells some of the equipment later.

 

[ilikegunspdx]

Yes - much better than the unboxing vids, or the ones where someone does a simple "smoke test".

I have to wonder how he can afford to purchase all of this equipment and take the time to test the stuff he does. I assume he makes $ from the advertising and maybe sells some of the equipment later.

Or he does what some of the airgun video "reviewers" do. They "buy" the gun, review it, then return it within the return time frame. Scammer scums.