Battery Tender Question ??

[billt460]

I just purchased a new lead / acid automotive battery from Wal-Mart. This battery is not for an automotive application. But rather for operating a 12 volt clay target launcher for shotgun shooting. They advertise up to 3,000 target launches between charges.

I also purchased a small, "Battery Tender Junior" to keep the battery maintained with the proper charge when it's not in use. These require you to keep the battery hooked up, with the "Battery Tender" plugged into the wall outlet constantly. This unit produces 12 volts at a maximum of 750 Milliamps, (3/4 of an amp). I was wondering how these things work? What is to keep them from overcharging the battery? I'm assuming they have some type of electronic sensors in them to prevent this.

We used the thrower once already. And it only took about an hour to bring the battery up to the fully charged level after we got home, as indicated by the steady green LED on the unit that plugs into the wall. We threw about 180 targets. Solid red means it is charging at maximum output. Flashing green means it has reached approx. 90% charge. And solid green indicates fully charged. I'm assuming that by leaving it hooked up to the battery all the time, it will maintain the full charge without causing an overcharge condition. Does anyone else use these? I haven't heard a bad word about them. I'm not real good about electricity, and wondered exactly how they work?

 

[racer12306]

I have a Battery Tender Jr. They has a brain and some programming in them that prevent the overcharge.

 

[Robenstein]

I have two of these chargers. As the previous poster mentioned they are a smart charger and will not overcharge. The battery in my 86 Monte Carlo SS is now six years old and still going like a champ and my Triumph battery is now 5 years old.

If the battery is heavily drained, these do take a LONG time to charge back up.

 

[mk378]

No problem with your setup there. The charger looks at the battery voltage to decide when to stop charging. So it is just plug and forget.

If you were out throwing more than a few hundred targets between charges, a "deep cycle" battery instead of an ordinary car battery would be advisable. For the limited use you're doing the regular battery is fine and costs less.

 

[billt460]

Originally Posted By: Robenstein
I have two of these chargers. As the previous poster mentioned they are a smart charger and will not overcharge. The battery in my 86 Monte Carlo SS is now six years old and still going like a champ and my Triumph battery is now 5 years old.

If the battery is heavily drained, these do take a LONG time to charge back up.


The new battery I purchased was sitting on the shelf for God knows how long. When I got it home I put it on a 6 amp charger I have, and it took a few hours for it to come up to full charge. I then hooked it up to the Battery Tender and after about 30 minutes it went from solid red, to flashing green, to full on green, where it has remained ever since. I keep the battery on a piece of wood. I heard never allow a battery to sit on a concrete floor, as it will drain it. I don't know if that's an old wives tale, but I keep it on wood none the less just to be safe.

 

[mk378]

Batteries have a little round sticker showing the month and year they were manufactured. Of course you want to buy a fresh one.

Manually charging with a larger charger after use is ideal since as Robenstein said, the tender really isn't intended to charge up a depleted battery.

 

[SZR48207]

I'm not so sure a battery tender is the right tool for a battery that may get more than a 40% drain during a session. I'm sure you aren't shooting 1200 clays at a time, but battery tender seems better suited to keeping a high charge on something with its own alternator.

Perhaps you can pick up a CETEK smart charger that can charge at a slightly higher amperage and also work for other applications.

 

[NormanBuntz]

I have one regular Battery Tender and three Juniors and have used them without an issue for four years. They come with a five year warranty. The Juniors have a microchip technology to keep them from overcharging the battery. Use it with confidence.

 

[SHOZ]

The cement floor concern was decades ago when they used rubber cases. As long as the battery is clean of acid on the outside of the case it is no longer a concern.

 

[eljefino]

Originally Posted By: Reddy45
I'm not so sure a battery tender is the right tool for a battery that may get more than a 40% drain during a session. I'm sure you aren't shooting 1200 clays at a time, but battery tender seems better suited to keeping a high charge on something with its own alternator.

Perhaps you can pick up a CETEK smart charger that can charge at a slightly higher amperage and also work for other applications.


Or even troll yard sales and get an old 6 amp charger for $2. Bring it up to 80% with that and use the tender for the last little bit.

 

[JHZR2]

There are plenty of chargers on the market. I am of the mind that a smart 1.5-2A charger is optimal for most situations.

With a proper smart charger, all is well. What it does is roughly this:

1) Check for polarity and voltage
2)charge constant current at whatever max rating is, until some battery voltage threshold is reached.
3) Maintain charge at that threshold voltage value and allow current to drop as the driving force (impedance-based overpotential) naturally reduces voltage input.
4) When current flow hits some threshold value, change to a float condition at lower voltage to avoid excess oxidation and electrolysis.

The threshold voltage and float voltage are temperature-dependent, so it is important to use a thermally compensated charger where possible.

It is also important to keep the battery on a float charge when possible. This will maximize the longevity, because batteries do self-discharge. Any state of charge lower than 100%will cause sulfation.

If youre looking for a wall wart, the battery minder 1500 model should fit the bill well.

 

[Quattro Pete]

Originally Posted By: billt460
I was wondering how these things work?

http://www.batterytender.com/Frequently-Asked-Questions/#answer5

BTW, I used to use one of these BT Juniors to keep my motorcycle battery topped up during off-season, but I did not keep it connected non-stop. Once a month I would just connect it for half a day or a day at most.

Then I got the BatteryMinder 2012, which is a bit more upscale as it has temp compensation and desulfation. I use it to top off my car battery once in a while since I mainly drive very short distances.

 

[doitmyself]

While using a low amp minder/tender on a vehicle, is it necessary to disconnect the battery?

What about a regular smart charger of 10 amps or less?

Thanks

 

[eljefino]

Nah don't disconnect the battery. It soaks up AC power spikes anyway. In fact disconnecting it might cause a worse spike when reconnecting the cable.

 

[Quattro Pete]

Originally Posted By: doitmyself
While using a low amp minder/tender on a vehicle, is it necessary to disconnect the battery?

Nope.

http://www.batterytender.com/Frequently-Asked-Questions/#answer12