Battery Maintainers

[gspren]

When I got my new Harley mentioned in another post they recommended keeping it plugged in to a maintainer if it wasn't going to be run for a week or longer. I bought the Harley branded maintainer, $34.99 &.750 milliamps, and I knew that it was probably no different than cheaper ones but bought it anyway to eliminate warranty questions. Now I think I'd like to get 2 more for both tractor and generator use where warranty is long gone so what's recommended?

[Raider Bill]

Battery Tender Jr's.

I've used them for years. Have 5 of them going pretty much all the time.

Wire in the adapters so you just plug and run.

Amazon.com: Battery Tender Junior Charger and Maintainer: Automatic 12V Powersports Battery Charger and Maintainer for Motorcycle, ATVs, and More - Smart 12 Volt, 750mA Battery Float Chargers - 021-0123: Automotive

I wouldn't be surprised if Harley didn't just rebrand these.

[snobdds]

I have 5 or 6 battery tender juniors kicking around that are on the tractor, mini ex, SxS, etc.  They work good.

In my trucks, I switched over to AGM batteries.  The battery tender juniors do not charge AGM batteries correctly.  The Battery tender Plus is for AGM batteries.

I bought a NORCO smart battery charger, which will charge any battery.  It also has a repair mode that I have used successfully to bring back two dead batteries.  That function alone paid for itself.  

Offsite photo removed by Admin.

[SawyerTed]

 

 

Battery Tender Jr works for me on my ATV.  On my motorcycle I'm using an Optimate3 on the recommendation of my motorcycle and ATV mechanic.  It does very well but I'm not convinced it's better than the Battery Tender Jr. 

[Tom King]

I have several of the Battery Tenders, but recently have bought the Noco Genius ones, and I like them better.  The Noco will charge different types of batteries.

NOCO - Our Products

[SawyerTed]

I have a NOCO jumper box.  It is awesome.  I didn't know they make maintainers as well.

[Tom King]

They make all sorts of "extras" too.  They have a nice plug in the wire going to the battery.  For things you want to use it on all the time, I use the pigtail that goes on screw lugs, and leave the plug hanging out where it's easy to get to, like on tractors that don't get used much.

The last time I replaced the batteries in a tractor, I bought Marine batteries, that not only have the regular battery posts, but also have machine thread posts.  I'll do the same for everything else in the future.  Those extra screw posts make it really easy to make nice setups to eliminate using alligator clips.

I also have a pigtail on the tractor batteries that fit the SAE plug I put on the diesel pump.

Trying to eliminate alligator clips altogether.  I used to always have to jiggle them to get the 12v diesel pump to run.

[Raider Bill]

I have 5 or 6 battery tender juniors kicking around that are on the tractor, mini ex, SxS, etc.  They work good.

In my trucks, I switched over to AGM batteries.  The battery tender juniors do not charge AGM batteries correctly.  The Battery tender Plus is for AGM batteries.

I bought a NORCO smart battery charger, which will charge any battery.  It also has a repair mode that I have used successfully to bring back two dead batteries.  That function alone paid for itself.  

Offsite photo removed by Admin.

I didn't know this.
I have AGM in all the bikes and using BT jr's.

[woodworker9]

My fishing boat has a Minn Kota brand charger/maintainer system.  I think it's great.  Its designed to leave it plugged in all the time.  It senses when the battery needs to be topped off, and does it automatically, and then shuts off when not needed.  Gives the batteries a "stir" every once in a while when not in use.  

My last set of 3 marine batteries lasted 7 years, and still going fine when I decided to just replace them, just because of age.  

I'm going to put a single charger unit in my dump trailer.  The little charger they put in at the factory takes 30 hours to charge the battery full.  Wayyyyy too slow.  The Minn Kota has all 3 batteries done in a few hours, ready to fish the next morning.  I run them almost empty every day I fish, and I usually go 2 or 3 days at a time.

[SwampDonkey]

I have a Honda one that I hook up to the SxS. I'm no expert on them, but I know the only one I have even seen in these parts off the shelf is by Honda. Never really went shopping for one, but I sure wouldn't get one from Canadian Tire and that is about the only option left in these parts. This one has all the bells and whistles, leave'r plugged in.

[Ed_K]

 Anyone using solar chargers?

[uler3161]

Anyone using solar chargers?

I have a couple of the Battery Tender 15w chargers. Ran over one, so I'm not sure if it works. The other one... well... apparently they have an issue where they will discharge your battery if there's not enough sun. I'm apparently having that happen. If I recall, it's something about a faulty diode. Not very happy. Wouldn't buy another, but I was thinking about getting one of the 10w ones from Renogy. I have some other Renogy solar panels and charge controllers and have been happy with them.

[Ianab]

If I recall, it's something about a faulty diode

Sounds right. A diode is a component that only allows current to flow in one direction. Any charger should have one built in to prevent current being drawn from the battery. If that shorts out, then current can flow in both directions. It's probably repairable if you can take the unit apart and know what you are looking at. 

[btulloh]

And in a small charger like that it can be most any general purpose diode like a 1N4001 or something.  About 10 cents in quantities of 1. 

[Gary_C]

I would guess it's more than just the presence, absence or a malfunctioning diode. I would assume the charger has to sense the battery status to charge properly and that requires a diode free line from the battery which could draw down the battery if there is no sun power for extended periods. It's kind of a dilemma without a good answer.

[Ianab]

I would guess it's more than just the presence, absence or a malfunctioning diode. I would assume the charger has to sense the battery status to charge properly and that requires a diode free line from the battery which could draw down the battery if there is no sun power for extended periods. It's kind of a dilemma without a good answer.

Possibly not in a small solar charger.  It's not a problem for the charge circuit to compensate for the 0.6v drop across a diode and still sense the battery voltage. Chances are there is just a simple voltage limiting circuit that lets the charge voltage go up to ~13.8V (+ 0.6 for the diode). 
The more exotic chargers have a microprocessor that senses the type of battery and adjusts the charge schedule to suit, but a little solar trickle charger is only going to be producing maybe 1 amp at best, so it's likely only voltage limited with a handful of components. 

[SwampDonkey]

 On my motorcycle I'm using an Optimate3 on the recommendation of my motorcycle and ATV mechanic.  It does very well but I'm not convinced it's better than the Battery Tender Jr.

The box I have here must have been rebranded because it has Honda on the box as well as Optimate3. I see some other stuff on your box is a little different. But mine was that marked price in CDN$, which would be US$20 cheaper. :D

[John Mc]

I've got a 2-bank Noco Genius charger in my antique military pickup. It's a 24V system, but I prefer to charge each of the two 12 volt batteries separately, rather than with a single 24 Volt charger.

The rest of my charger maintainers (I have about 5 more) are all BatteryMINDer brand. I've had very good luck with them - my oldest is almost 20 years old and still going strong. They are all temperature compensated (the ideal voltages for bulk charging and for floating vary with temperature). They also have a desulfation feature (which has successfully recovered a couple of weak batteries).

I won't buy a charger without the desulfation feature or temperature compensation anymore.

[gspren]

I've learnt a lot here, after each recommendation I looked them up and still don't know what's best but since I want a couple I may get a BT-JR for the barn (Kubota UTV and old gas powered welder/generator) and a NOCO Genius for the pole building with my truck and tractor. Still need to decide on something for the boat in DE (3 batteries).

[SawyerTed]

On my motorcycle I'm using an Optimate3 on the recommendation of my motorcycle and ATV mechanic.  It does very well but I'm not convinced it's better than the Battery Tender Jr.

The box I have here must have been rebranded because it has Honda on the box as well as Optimate3. I see some other stuff on your box is a little different. But mine was that marked price in CDN$, which would be US$20 cheaper. :D

I didn't pay $62.50 for mine even though the tag says so.  I've done a great deal of business with my motorcycle and ATV repair guy.  He discounts heavily for his best customers.  I think I paid $45 or so for it.  Of course he gets the friends and family rate at the sawmill.  It all comes out in the wash I suppose. 

[John Mc]

I've learnt a lot here, after each recommendation I looked them up and still don't know what's best but since I want a couple I may get a BT-JR for the barn (Kubota UTV and old gas powered welder/generator) and a NOCO Genius for the pole building with my truck and tractor. Still need to decide on something for the boat in DE (3 batteries).

Just remember that the Battery Tender brand chargers do not have desulfation (at least not last time I checked). If you keep your batteries charged all the time, that may not be a concern, since sulfation generally only forms when a battery sits partially discharged for a time. Since batteries self-discharge over time, it's a concern for equipment let unattended for extended periods. If you leave it on a battery maintainer when not in use, then desulfation is usually not a concern.

[Iwawoodwork]

I have used the Harbor Freight battery tenders for the past 15+ years, as I recall  I was buying them for $3.99 back then now about $5.99. I have about 10 and they seem to work fine.

[John Mc]

I have used the Harbor Freight battery tenders for the past 15+ years, as I recall  I was buying them for $3.99 back then now about $5.99. I have about 10 and they seem to work fine.

If you do buy these, measure the charging and float voltage. The owner's manual says "provides a maximum of 13.2 volts", but the HF maintainers have a reputation for having a high number of out of spec units. Some of them operate to spec, others run at too high a voltage. Once the battery is charged, the "float" voltage should be  13.2-13.4. However, some of them seem to run at 14.2- 14.8. You might get away with this for a quick toppin goff of your battery, but voltages this high can boil off electrolyte and damage the battery if left connected too long. If you leave these inexpensive chargers connected for long periods, be sure to check the float voltage.

Do NOT use these chargers on Gel batteries, since they need a lower charging voltage and can be easily damaged by over voltages. (An AGM battery generally take charging vltages equal to or slight greater than a regular flooded lead acid battery, so should not be damaged if this charger is operating at near its specified 13.2 volts

[beav]

Don't use a battery charger as a battery maintainer and dont use a maintainer as a charger. There is a huge difference

[SawyerTed]

I have used the Harbor Freight battery tenders for the past 15+ years, as I recall  I was buying them for $3.99 back then now about $5.99. I have about 10 and they seem to work fine.

I'm glad someone has gotten good service from HF stuff.  
I had a HF winch on my ATV, it shorted internally, the fuse didn't melt and it nearly burned my ATV up.  The replacement winch, a gift, came from that tool place with northern in its name.  It had a dead short that repeatedly drained my battery.  I've learned my lesson, I won't attach an electrical device from HF or NT device to my house, motorcycle, boats, ATV, tractor, sawmill, truck, cars or anything else I value.  Just my .02.