Battery tender,..do they work?

I just recently bought the deltran Battery Tender for my GN, now I gota get another one for my GS. Well worth the $$.
 
I use one from Sears. The good....car always started. The bad....battery still died after 5 years. I guess when they say the battery will last 60 months, they really mean it!
 
Batteries unlimited inc has the Battery Tender Jr on special for $20.73. Thats the one I use and with that price I will get another.
 
Yes, battery tenders do work! But DO NOT TRUST the cheap Harbor Freight ones or equivalents. Spend a little more & get a quality unit. We had the unfortunate experience of 3 batteries burning off from overcharge with the cheapos. One battery was salvageable, the other 2 needed replacement.

Batteries are sensitive to many parameters. If managed well, they'll live a long life. If not, their service life & discharge depth drops off quickly.

Battery tender or not, it's a good idea to start a vehicle at minimum once per month & run it for 12-15 minutes. If equipped with A/C (R-12 or R-134A systems alike), run that too for the same period to keep the seals up & oil circulated. Saves having to replace a seized compressor later, and keeps you from leaking out freon.

I guess I will need to remove that cheapo and get a battery tender!
I notices that it never says charged. So that means it's always charging.
 
I have a Schumacher one from Walmart and it keeps mine topped off. Has a yellow charging light and a green charged light.
 
I have a Schumacher also. Sounds like we have the same one. Brought it for $20 f Rom walmart and it's been working perfectly for 2yrs now. Plug it up and walk away. No need to check on it or think about it

Sent from my HTCONE using TurboBuick Mobile mobile app
 
I guess I will need to remove that cheapo and get a battery tender!
I notices that it never says charged. So that means it's always charging.
My Sears battery maintainer/charger never really charged the battery. If I put it on a slightly discharged battery, the charge light stays on and never goes off. If I charge the battery with my Schumacher charger, then the Sears unit will keep it charged (green light stays on).
 
Good responses, thanks guys.

I like the Battery Minder model 12248 which has a desulphating mode. I have a couple of Optima batteries that are both over six years old and still plenty strong, thanks to the Battery Minder. It is not cheap but it works very good.

The only problem with the 12248 charger is it occasionally switches to gel mode on its own. This has not been a problem for me. The manufacturer says this is due to poor connections but that does not seem to be the case. No big deal.

I always disconnect the battery from the vehicle's electrical system before charging.

http://www.amazon.com/BatteryMINDer-Volt-Amp-Battery-Charger/dp/B000X2B0RW/ref=sr_1_7?ie=UTF8&qid=1379489935&sr=8-7&keywords=battery minder

Make sure to get the temperature probe:
http://www.amazon.com/BatteryMINDer-Volt-Battery-Temperature-Sensor/dp/B001DZNDKK/ref=pd_sim_auto_4

You may find both the charger and temperature probe at a local Northern Tool store.

Paul Lohr

You might not realize it - but you hit the nail squarely on the head.
One of the biggest problems with long term float on a FLA battery is sulfation.
If the battery is not a full state of charge - little crystals form on the plates.
Some can be reversed with a boost voltage, some can't.
That's why - in addition to all the other things mentioned about lubricating seals and such - it's a good idea to "exercise" the battery; i..e discharge via starting and other means - or at least use a charger that has a equalize or boost voltage at constant current mode; i.e. desulfation.
Not to be confused with NiCad memory excercising
A common cause pr premature failure of marine batteries up north, where the off season is long.
We recommend owners connect a light bulb across the terminals - with a timer to simulate the discharge. Although not ideal, as a 30 sec discharge rate is better.
Yeah - Deltran has been at it a long, long time.
Even though the green is the standard traditional unit I recommend the pink one - goes good with these fine Buick accessories.
 

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My Sears battery maintainer/charger never really charged the battery. If I put it on a slightly discharged battery, the charge light stays on and never goes off. If I charge the battery with my Schumacher charger, then the Sears unit will keep it charged (green light stays on).

Can't say the same for this one. It charged my battery from 6v to full. Just when it's full it never shuts of. I guess it's ok. As long as it doesn't burn my car up.
 
My Sears battery maintainer/charger never really charged the battery. If I put it on a slightly discharged battery, the charge light stays on and never goes off. If I charge the battery with my Schumacher charger, then the Sears unit will keep it charged (green light stays on).

Most likely an oder CFR style, that doesn't have Bulk & Absorb charge modes.
Does it weight like 70 lbs? Then it's a CFR style.
I had one of those too. Ole Bessy.
 
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My GS sat for 6 months battery dead. Boosted it off a few times. Put the tender on it, red light stayed on for 4 days before it went green. So It does charge and maintain..
 
The other thing you can do is - you can buy the Horrible Freight DVM and occasionally measure it.
Should be approx 14.1VDC - without charger
Probably a little less depending upon temps, charger etc.

The other thing not mentioned is applicable to cold weather guys and storage / charging
Although not nearly as critical in cold as high temp - temperature compensation will adjust the chargers output accordingly.
To my knowledge, I don't think any of the small, home use units incorporate such a thing.
For long term best - bring the battery inside and float it.
Optimal storage temps for a FLA battery are approx 77 deg F.
They live long at that temp.
 
Can't say the same for this one. It charged my battery from 6v to full. Just when it's full it never shuts of. I guess it's ok. As long as it doesn't burn my car up.

To my thinking - it should not shut off.
I know ours don't.
It will operate in constant voltage mode then; i.e. 14.1 (2.35 Volts per cell for FLA battery) to keep it floated at full charge.
 
Most likely an oder CFR style, that doesn't have Bulk & Absorb charge modes.
Does it weight like 70 lbs? Then it's a CFR style.
I had one of those too. Ole Bessy.
No, it is little, like a batterytender. My Schumacher is about the size of a loaf of bread. It has a needle that shows the battery strength. It seems that it gives you more info than the small battery tenders with no needle. Is there anything wrong with charging the battery with the Schumacher and leaving it hooked up, to keep the battery charged?
 
No, it is little, like a batterytender. My Schumacher is about the size of a loaf of bread. It has a needle that shows the battery strength. It seems that it gives you more info than the small battery tenders with no needle. Is there anything wrong with charging the battery with the Schumacher and leaving it hooked up, to keep the battery charged?

Ahhh...maybe it was just weak kneed? Or - some chargers are just...how do you say....crappy? ;)
I would have to see the particular model of the Schumacher to determine its capabilities.
I like the needle of the DigitalVoltMeters - they are much more accurate. :D
As far as keeping a "charger" hooked up - some cut off - some stay on float.
Again - the basic function required is just a long term float charge at approx 14.1 V (2.35 VDC/per cell x 6)
the reason they are small is that not much current (milliamps at float) is required - just (or mainly) voltage
 
I've got four Battery Tender, Jrs. In my opinion they work absolutely great. Have had them for almost 9 years. A lightning strike out here in the sticks fried one of them a few years ago......I wrote Deltran about it, and they told me to send it in, and they'll send me a new one....no charge. And they did......Talk about customer satisfaction......it's nice that when the battery is fully charged, they cut off. Safe, efficient, dependable....never overcharges.......I like the feature of the quick disconnect line it comes with.....thus, I keep the Battery Tender outside on our porch, side of the house, in the car port hooked up to my Jeep's battery.....I just unplug and disconnect whenever I take the Jeep out.....in the garage I have one on the Grand National battery, the lawn tractor battery, and a spare new battery. In our basement, I have one on the generator battery. All have worked extremely well... If you need to use one and you don't have a garage or carport in order to keep it out of the weather, use an extension cord to the Battery Tender, run it up under the front to the engine and keep it under the hood hooked up to the battery.....I did that for quite a while when I had a Jeep sitting outside in the weather.......just keep rain/snow off of it......if you can get one at Walmart at that low price, get it.....I got all of mine at Pep Boys for $29.95 each....I didn't even know Walmart sold them....

Bruce '87 Grand National
 
I've been using the "Optimate 6" for the last few years & am very happy with it. It's a desulphating / battery maintainer. It's not the cheapest priced unit out there, but I got sick & tired of replacing less expensive units when they stopped working properly. This has served me well over the years & has been trouble free.

Pull my battery in the fall when the car is put into winter hibernation & store it in my basement (off the floor) with the Optimate 6 connected over the winter.

http://www.tecmate-int.com/pdf/TM180-PL1-091028_EN.pdf
 

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I have two of the Battery Tenders that has 4 chargers built in one , it works great , it has payed for it self many times since I have bought them in saving my batteries .
 
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