Didn't want to mix this up with the battery jumper box thread.

These days of working from home my car doesn't get much use. I maybe drive it 2-3 times per week and even then rarely more than a couple of miles. I've noticed the starter cranks more slowly since the battery is being used but isn't being charged much. I have a CTEK tender on my motorcycle battery for the winter months and thought of getting a tender for the car.

Anybody have a good recommendation? Don't need a quick charger, just something to leave attached to the battery for a while to keep it charged up. Car is a 2004 Honda CR-V with a standard 12 volt battery.

Sounds like starting it uses more power than the alternator can replace in the short distance you drive. It's a common problem. Also, as soon you turn the key, a bunch of electronics get active and they all pull from the battery.

https://www.batterychargers.com/en/...v12v-automatic-battery-chargermaintainer

I've been using a BatteryMinderPlus on my hotrod for quite a while and it has worked fine for me. I'm pretty sure all the tender type chargers are about the same except for the price... I have an AGM Optima battery in my hot rod and they are more particular about how they are supposed to be charged and I haven't had any problems using this system.

Bob

I have a bunch of the Harbor Freight maintainers. You can get them for 5 bucks on sale if you keep an eye out. I use them through the winter months on both of my boat batteries, my bike, and my lawn tractor. Been doing this for many years.

Is your car kept in a heated garge, unheated garage , or outside? How far do you drive?

Google it or talk to your local CarQuest/O'Reily/Napa. I think they come pretty cheap, and some can be installed under the hood and plugged in like a block heater. If outside, a battery heat cover may help, also. Cold batteries lose much oif their cranking power.

Just remember to unplug it when you leave .......

I've been thinking of getting a shop model for my RV/Boat batteries, which are just out sitting on the bench in the heated garage. Topping them up every month or two is not really that much of a PITA, so I've been putting it off.... but old age is for lazy.

Our vehicles are kept in a heated garage, and it's about a 10 mile OW trip to town, That seems sufficient to keep the batteries up, tho I may put one and a battery cover(s) in the Expedition, for winter trips to the Interior, when the car has is kept out overnight in temps to -50. Block heater plugged in if possible.

So far, no problem, but I told my wife we are not going to go "camping" in a rental cabin without electricity again as we did last year. (-35) Getting up every 3 hours to warm the car and stoke the POS wood stove is for the young and/or foolish.

OK, I'm late to the party while typing, I see.

I have been using Harbor Freights el cheapo's for over 20 years on several batteries, motorcycle, ATV, cars etc. with good results

Interesting that this thread showed up today....

I help maintain the fire engines for the volunteer fire dept. Today I changed out the batteries on one of the engines and they were 9 years 2 months old. I'm not sure what brand of trickle charger is on the engines, but when the engines are not in use, they are plugged up 24/7, and kept in a station that is semi-heated. Meaning that the thermostat is set at 50 degrees.

One of the things that helps the batteries last longer is that we have master cut-off switches on the engines. You flip the switch and all power to the engine is off. No power anywhere, so the trickle charger is actually doing very little, but the batteries are kept fully charged.

I you'd like, I can check and see what brand of trickle chargers are on the engines, and let you know.

I have an 2005 CRV... and that has been my opinion as well.

I use BatteryTender units on various things...

At $60 (IIRC)... I have been quite satisfied. From diesel gensets... Cummins trucks... CRVs... never a complaint.

I use Battery Tender on the important stuff - the car we seldom drive in the garage and my motorcycle.

The harbor freight brands on my mowers and boat battery

It has extended the life on my mower batteries by at least 3 years.

I'm a firm believer in Battery Tender brand. Have one on my tractor and one on my 09 motorcycle that is still running the OEM battery. 11 years on a battery, first time I've ever had a battery last that long. Has made a believer out of me.

I have a battery tender on my Lexus SC 430. With the sensors, alarms and other stuff that are constantly on even with the ignition off the battery will drain down in less than a week of non use. Battery tender will keep up with the normal drain.

If you have any old 12v fractional amperage transformer plugs from an old cable box etc that should work.

Look at the output amps on you battery tender and compare.
You want one with less amps not more.

Or you could just forget all the add on dew-dads and buy an Odyssey Battery. The first set in my diesel truck lasted 11 years. My truck sat for 2 weeks in sub-zero overnight cold one time in January. For a reason long forgotten, I had to start it up one night at -15 below zero at the end of that two week cold soak.. It started right up. My truck has never been kept in a garage either.

I use Battery Tender.. Probably have at least a half-dozen of 'em and they work very, very well..

I've used a pair of these for the last 15-20 years on various things:

https://smartercharger.com/products/ctek-mus-4-3-test-and-charge

It only needs to be "smart" if it puts above a certain amperage.

I have a few pulled batteries for lights in my cargo trailer hooked to a pair of small 6v solar panels in series.
Bright sun gets the output around 18v at around 0.2A these used up batteries have been at it for years.

You could also set up a regular top up with a regular charger .
As the Military does with depot vehicles.

Or find the IOD (ignition off draw) fuse and pull it. That will work like the master off mentioned earlier.

I picked up a 4-bank Battery Tender brand charger last fall. With motorcycle, lawn tractor, generator and atvs stored over the winter it made more sense that several stand alone chargers. Also picked up several different length terminal cables for it so I can reach the different equipment stored inside the garage without pulling all the batteries.

I keep Battery Tender chargers on my tractors, and also use Schumaker brand that's good

happy with this one
https://smile.amazon.com/gp/product/B07W8KJH44/

A tender/trickle charger is good for lead acid batteries but you have to keep it on all the time. As mentioned by Walt501 above, an Odyssey (or other good AGM) battery will not self-discharge so much. Also note that AGM batteries are charged with a 40A charger not a <2A charger. When buying a charger, look carefully at the duty cycle because there are a lot of high claims out there "40A" but the fine print tells you it's intermittent and might be as low as 10% duty cycle. The continuous rating might instead be 4A, but the charger will be labeled "200A Start" and "40A Boost" -- it's all smoke. If you study it carefully, you'll see a lot of the high-amp starting claims are actually the current at 3.6V. It's not surprising the current spikes to 100 or 200A because the voltage sags so low when you start cranking -- what a pathetic joke.

Basically, if you want something better than a trickle charger, it's going to take a big-ass transformer and they're usually mounted in a rolling cart and cost several hundred to a thousand dollars or more. Just think what it takes to deliver enough current for welding. Don't try to weld with a little lunchbox size piece of junk, and don't try to charge a big battery with a little wall-wart.

FWIW, like Walt, I've got Odyssey batteries -- my first one was a Sears DieHard Platinum (rebranded Odyssey). I still have it in my big pickup after 11 years. I have about a half dozen of them in vehicles and they're all about 5 to 10 years old and they all work. The ones that don't get used (because they're backup batteries on the 4x4 etc.), I put on the battery cart once a year. I just went down to Napa and bought whatever the biggest battery cart they had was. The AGM prefer a fast charge.

My wife's car is the only one with a lead-acid battery because it's a 2019 and it came from the manufacturer that way. Three months of quarantine and it was dead. Eventually, I'll swap it out because it won't hold a charge, usually after 4 years. I'll put another Odyssey in it. They cost twice as much but last at least 3 times longer and never need a trickle.

Have kept a bunch of old trucks for the past 30 years - sometimes as many as 20 ranging from pickups through fire engine and Mack LTL - and most of them are driven only by me, so they mostly sit.

Almost all use lead/acid batteries and most of those last 12 or 13 years if kept fully charged. Have had success with the Battery Minder (have added wiring to trickle 4 batts per unit) and the cheap units from Harbor Freight have been very dependable - one unit per batt.

I have downsized a bit with the fleet.

Thanks for all the tips and recommendations. Ordered a Battery Tender Plus yesterday, it looks like it will meet my needs well.

Jim, the best one that I’ve used is the Stanley One Touch. Not so much for the charger as that works fine too, but for the accessory DC plug that charges through the cigarette lighter socket. I ordered two more of those DC accessory plugs and cords from Stanley because they can be used on the Battery Tender Plus and the .2 amp tender less expensive Walmart Battery Tender because those two both have the split cord that you can use either the alligator clips or the cigarette lighter socket plug. I never have to lift the hood or worse get to that battery under the back seat. The Battery Tender units only come with the alligator clips, but they do have the split cord and the Stanley DC cigarette cord attachment works great.

Most of them work well.

CTEKs are really nice and will have settings for a variety of types. AGMs require a slightly higher charge voltage, wet batteries, lower. Especially deep cycles.

And no, throwing an AGM in a vehicle with any kind of parasitic drain, which is about everything, for months of stationary sitting, will be even "deader" than a wet battery.
Unhook it and throw a maintainer on it if its setting extended periods.

Low n slow is always preferred, regardless of type.

here ya go

At some small company I designed the nicad battery chargers in the Boeing 767 and years later the 777.

I have friends who designed Lead Acid battery chargers.

They are disgusted with me for letting the batteries in my truck and my car go dead during Covid 19.

I paid for 2 new batteries and a battery charger.

I learned my lesson and now my batteries are ready for the next pandemic.

A few years back, I parked my truck in the garage and went south for the winter. When I came back the battery was completely dead having powered all the security and what ever else that Ford has running through the computer. The last couple years I've had one of those low amp trickle chargers running only a couple hours a day on a timer and that worked well. This year reading the Battery Tender trickle charger instructions, it said that I could leave it connected and it would maintain a full charge in my one year old battery. Okay, since the cars get better mileage and I didn't need 4wd, I parked the truck for a couple of months with that trickle charger plugged in full time. Fast forward to the hunting season and 20 miles down the road my Sync system touch screen goes out. Ford dealer says my Apim is defective and it can't be rebooted. Coincidence maybe, but for the price of a new Apim and Sync display screen installation, I could buy lots of new batteries. I won't be plugging in that trickle charger full time any longer.

I've gone the opposite route on the semi trucks and the farm trucks by installing battery interrupt switches. Anything that gets parked for any length of time gets the switch turned. Yes, you have to reset the clock, but small price to pay compared to dead batteries.

On some of the newer vehicles, the ECM can end up losing IT'S battery charge if not powered for a long time, losing all it's settings. That is a major potential negative.

A flooded lead-acid battery will self-discharge at 4% per week even if you disconnect it. AGM self-discharges at about 1% per month. The flooded lead-acid also has only a 50% Depth of Discharge, whereas AGM can go down 80% DoD. Essentially, the flooded batteries kill themselves faster and they can't go down as far before they're down for the count. The only way to keep a flooded lead-acid battery alive is to keep it on life support all the time. What they're good for is cheap initial cost, repeat sales, and sales of chargers, tricklers, jumper cables, dual-battery isolators, disconnect switches, and booster packs, as well as roadside assistance service subscriptions and tow services. $$$$$

Attached is a link to CTEK battery charger. These chargers are included in most high end vehicle purchases in Europe. Buy a Mercedes and get a smart charger included. A smarter charger needs to be used if you plan on leaving it connected for a while. Most service chargers don't even know if a battery is connected.
https://smartercharger.com/collections/vehicle/products/ctek-multi-us-7002

Keep it out of the weather.