Battery Tenders

I'm looking to purchase two battery tenders for my 24 volt JD tractor. What amp works best? I'm looking at the Battery Tender brand, they recommend a 5 amp for a tractor. That seems like too many amps. I'm thinking the 1.25 amp might work or is that not enough? Has anyone had any experience with either one of these Battery Tender sizes on a tractor? Thanks in advance for any input.

from what I have read its better to charge your battery slow so they say 2-3 amp is the max. I have several 2 amp maintainers I use during the winter when I take my batteries out and put them in storage. works well for me. I have some batteries that are 8/9 years old and going strong. with the price of batteries I try to baby them to get longer life out of them. I also use water from my dehumidifier if needed.

The attached link is one reasonable choice. The ad says something about 6 or 12 volts, but read the front panel with the magnifier. Jim
Untitled URL Link

I have an old one I got out of a box of misc.at an auction,its 1.5A works good,its the best thing I know to bring back a really discharged battery so it'll work again.Takes awhile maybe a couple days sometimes.

The amperage required will depend on the charger/maintainer. The older style trickle chargers would put out a certain amperage and that was it. The maintainers are capable of their maximum listed output, but will reduce output as the battery reaches a complete charge. I have found that some of these will go into overload and not do anything if they are connected to a battery(ies) that are not quite fully charged and are drawing more amps than are available.

A 5 Amp battery maintainer doesn't just pump 5 Amps of charge into your battery 24/7.

Battery maintainers only apply current to maintain the battery charge, anywhere from ZERO up to the rating of the maintainer. On a good battery they will spend most of their time at zero.

Tractors tend to have large capacity batteries, so having that relatively high charging capacity can be beneficial.

I always learn something from you.

That is good. if there is a formula for it forward that in a brown paper wrapper to the lamp post on 12th St. and 8th avenue St. Cloud MN. I need it for my University Students. Jim

ih, that so called "5 Amp" rating likely represents the MAXIMUM current it might deliver to a battery but what's actually pumped through the battery depends on its condition and State of Charge IE its NOT (but subject to its design and specs which I don't have) going to constantly pump a full 5 non stop amps. As you likely have fairly high capacity batteries and based on what I just described I DONT SEE A SO CALLED 5 AMP MAINTAINER EVER HARMING YOUR BATTERIES. In fact for heavy duty typical tractor batteries I'd prefer a 5 over a 1 amp charger subject to specs and quality.

Sure a 1 amp can "work" but likewise Id bet that 5 amp will work fine as well.

John T

My understanding is that a "maintainer" is just that, it maintains an already charged battery.

If the battery is low, charge it first with your regular charger, then connect the maintainer. When maintainer senses a drop in charge it will kick in to maintain full charge.

I have several Schumacher 1 1/2 amp versions and am happy with them. One of them is on a group 31 1000 amp hour battery and has no problem keeping it up. The maintainers spend most of their life on standby mode. I believe they extend the life span of my batteries.

This is what I use

https://www.northerntool.com/shop/tools/product_200332201_200332201

I sell around 35 batterys a year I always have a 4/5 descent battery's around for use in my tractors are to run/test 12V equipment/tools.

If I judge a battery to still have some useful life I put a maintainer like I posted on them, ones that are down it takes a day maybe two to bring them back to a fully charged state.

While I am working on a project I install one of these so the battery will be ready when I need to fire it up. I have chargers to get the job done right now I would not use it if I were in a hurry...

I have no complaints other than to say if I were to use it as a long term maintainer wire it directly to the battery.

I have Battery Tenders on everything from antique vehicles to my riding lawn mower. Love 'em. They come in many different sizes from .75 amp to 3 amp and more. I use the little .75 amp ones on my riding mowers and cars. I have 1.5 amp ones on one smaller tractor and a pair of 3 amp models on my 3020 (two 6v batteries in series-- one on each battery). The 3 amp model is nice because it can charge 6v and 12v batteries.

Any of them work, but like others have said, if the batteries get really run down you need more amps to bring them up from near-dead. I've found that the little .75 amp models don't cut it when the batteries get too far down. So for the bigger stuff I use the bigger Battery Tender models. I leave them hooked up on the little quick-disconnect cord that comes with them all year long. Just unplug and go. They're great.

I do use then. However get good ones from name brands. I had two batteries destroyed from cheap maintainers. I should have checked , however batteries were back behind other tractors stored in used semi trailer. Old age prevented me from checking as I should. Batteries in question were older but useful.

Bill,
I something use 2 amp smart charger. It shuts off when battery is fully charged. I remove charger when its done.

IMO IF you have to leave a charger on battery 24/7/365 your battery is on life support , self discharges, and on Last leg. Or you have something draining battery.

I do have a charger that may take a week or more to complete a desulfating cycle. It's always connected to a battery
George.

(quoted from post at 15:08:58 01/01/20) Bill,

IMO IF you have to leave a charger on battery 24/7/365 your battery is on life support , self discharges, and on Last leg. Or you have something draining battery.

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Battery Tender (brand) are not battery chargers. They are "tenders," aka maintainers. They are specifically designed to be left hooked to the battery indefinitely and function best when they are always left connected (whenever the vehicle's not in use, obviously). I use them on everything besides my daily drivers. I put mine on the day I get a new battery and never take them off again until the battery eventually dies (which usually takes about twice as long as without using a tender). They're great for modern vehicles with lots of electronics that draw down the battery even when they're just sitting around and they work fine on old iron, too.

http://products.batterytender.com/Chargers/

From their website:

[b:3f83a10d63]How are the BatteryTender Plus and Junior battery chargers different from other automatic battery chargers?[/b:3f83a10d63]
[i:3f83a10d63]Many automatic battery chargers simply turn off when the battery voltage rises to a preset level or when the charge current falls below a certain level. With the battery sitting idle, its internal losses will consume much of its stored charge. Depending upon the age and condition of the battery, it may only take a couple of months before the battery loses more than 90% of its charge. The amount of charge lost tracks pretty well with the reduction in battery terminal voltage.

Some automatic chargers will restart when they sense that the battery voltage is too low. As a battery goes through these types of cycles of repeated charging and idle self-discharge to low capacity levels, the useful battery life may be dramatically reduced.

Both the BatteryTender Plus & Junior battery chargers do not turn off after they charge the battery. They automatically switch to a safe float voltage level that keeps the battery charged and yet does not do any harm to the battery. In fact, in most cases, this type of charge maintenance will extend the battery s useful life by at least 50%.

Some customers have reported battery life increases of more than double what they had before using the Battery Tender Plus or Battery Tender Junior battery chargers.[/i:3f83a10d63]