battery tender vs. battery minder

[bioburner]

I just picked up the Stanley Fatmax too. Was $21 with a extention cord and three ways to hook into or on battery. Those three connectors alone would run close to $15. Clamps, duplex and power connector.
Will probably be the one to put in the camper

 

[dblshock]

I run 3 $28 NoCo Genius .750... Boat, tractor and stowed car.

 

[JimPghPA]

Saved for future reference.

 

[02SE]

Originally Posted By: NissanMaxima
Thanks everyone for all the great information. I didn't know about temperature compensation so that was a good tip! I will definitely want that being in Colorado. I will look at the other recommended units besides Battery Minder, but at Walmart today I saw Schmacher and know they've been in business a long time. I called and they recommended the SP1,SP2 and SP3 for maintenance and either the SC1000A or SSC1000A for dead batteries and maintenance. Is Schumacher good?


Let me put it this way.

I can get Schumacher products for free. Despite that, I still have 7 Battery Minder's that I bought.

 

[NormanBuntz]

I've had bad luck recently with Battery Tender Juniors. I've bought four of them in the past four years, and two of them have gone bad (stopped charging). My regular Battery Tender with the metal case never misses a beat.

 

[BigD1]

I bought a Schumacher SC2 last year at Walmart online for $12 or $13. They were $20 something dollars in store. Kept my Volvo battery on it all winter, and then in March of 2016 took it off, and the battery has been fine. Battery was on the charger for over three months. Got some repairs to do on my Volvo, but they can wait till spring, so the battery is going back on the charger again this year for two to three months, and I expect the battery to be in fine shape again.

Sure there are better chargers out there, but I don't need temperature compensation because it's not mission critical. I keep the battery in an unheated block building that I use for storage, and I know last year it got down to zero degrees a few times last winter. If I lived where it got below zero lots, then I would buy a charger with temperature compensation.

 

[901Memphis]

The problem with some of the Schumacher products is the voltage control/charging algorithm . I had one that took my battery up to 16.2+ volts on standard flooded setting. These should never see anything over 15v even if freezing, it will boil the electrolyte in a hurry.

Yes you can charge a battery with higher voltage but it's very abusive and not the correct way to do it.

The charger should bring the voltage up to where it needs to be and hold it around 14.7v or thereabouts at a constant voltage while the amps taper depending on temperature and chemistry.

 

[RooflessVW]

I have a dual-bank Battery Tender that is on both of the batteries in my car for 9 months out of the year.

My left battery (AGM) is the original and is approaching 13 years old. The right battery was replaced in 2012 when the original post a cell.

It's only downfall is that it cannot act as a power supply for coding/diagnostics. I am still looking for something to fulfill these duties.

 

[Quattro Pete]

Originally Posted By: rooflessVW

It's only downfall is that it cannot act as a power supply for coding/diagnostics. I am still looking for something to fulfill these duties.

Noco G7200 has a supply mode, although I've never tried it.

 

[JiL]

Originally Posted By: rooflessVW
It's only downfall is that it cannot act as a power supply for coding/diagnostics. I am still looking for something to fulfill these duties.

Using one of these has worked really well: Power Max RV Converter Battery Charger PM3-55 AMP 120 V AC to 12 volt DC Supply

http://www.ebay.com/itm/Power-Max-RV-Con...y-/152357486323

 

[440Magnum]

Originally Posted By: 901Memphis
Originally Posted By: Donald
Most chargers that can maintain are not as good at maintaining as the quality battery maintainers.


The pro Logix does both exceptionally well, my PL2320 even applies a load to the battery after 96 hours of being completely charged and then starts charging it again before going back into maintenence mode and monitoring the voltage. It's also got temperature compensation too.


Yep. Its all-around better than any dedicated "tender" or "maintainer" I've ever encountered. The periodic load and re-charge is impressive in its ability to prevent (or to an extent, reverse) sulphation. The first battery I tested mine on was an old lawn tractor battery that wouldn't hold a charge overnight any longer. After leaving it on the Prologix for about 2 weeks, it worked for another year in the tractor without any need to go back on the charger- it would eve start the tractor after a week or two of sitting.

I also left one of my .sig cars on it for 9 months, and the battery is still going strong (of course that's also an Enersys-built AGM that does fine sitting un-charged for 6 months, so its not that strong of a testimony.)

 

[Bgallagher]

I would take it out and keep it in your basement or someplace cool and dry.

 

[Quattro Pete]

Originally Posted By: raytseng
I have a battery minder, and you should be aware that there is a big downside of the batteryminder in that it has a quite high self-drain back current.

Good to know. I'll have to see how my other chargers behave when turned off.

 

[Quattro Pete]

Originally Posted By: Quattro Pete
Originally Posted By: raytseng
I have a battery minder, and you should be aware that there is a big downside of the batteryminder in that it has a quite high self-drain back current.

Good to know. I'll have to see how my other chargers behave when turned off.

I just did some measurements with a clamp meter. With each charger connected to the battery and not connected to power, I get the following:

BatteryMinder 2012: 4 mA
Noco G7200: 12 mA
Solar PL2320: 7 mA

I guess I'm not seeing the high self drain-back current that you mentioned. The above current is peanuts compared to the car's own parasitic draw.

 

[George7941]

To measure a few ma of current to a reasonable degree of accuracy with a clamp meter requires an expensive (few hundred dollars) clamp meter. Which clamp meter are you using?

I suppose the cheaper meters will do for comparison purposes, i.e. does one charger draw more than another?

 

[Quattro Pete]

Originally Posted By: George7941
To measure a few ma of current to a reasonable degree of accuracy with a clamp meter requires an expensive (few hundred dollars) clamp meter. Which clamp meter are you using?

I suppose the cheaper meters will do for comparison purposes, i.e. does one charger draw more than another?

Uni-T UT210E. Yes, it's a cheap meter. I don't claim the results to be super accurate, but just to give some point of reference. By comparison, it shows parasitic drain on my old BMW to be around 80 mA, and on wife's Q5 - around 35 mA. So, even if not very accurate, you can see that what the charger draws is significantly less than what the car draws on its own.

My main point was that BatteryMinder does not seem to be drawing any more current than other chargers/maintainers, when off.

 

[George7941]

The industry rule of thumb limit for parasitic drain is 50 ma, with newer cars with more modules drawing more than older cars with fewer modules. So your older BMW seems to have an abnormally high parasitic drain. You might want to measure the draw accurately with a multimeter with its leads connected to the circuit, instead of a clamp meter.

 

[Quattro Pete]

Originally Posted By: Quattro Pete
I just did some measurements with a clamp meter. With each charger connected to the battery and not connected to power, I get the following:

BatteryMinder 2012: 4 mA
Noco G7200: 12 mA
Solar PL2320: 7 mA

I remeasured using a multimeter and test leads since as was pointed out by George, a clamp meter may be way off given such low current:

BatteryMinder 2012: 0.38 mA
Noco G7200: 0.44 mA
Solar PL2320: 1.12 mA

 

[Quattro Pete]

Originally Posted By: George7941
The industry rule of thumb limit for parasitic drain is 50 ma, with newer cars with more modules drawing more than older cars with fewer modules. So your older BMW seems to have an abnormally high parasitic drain. You might want to measure the draw accurately with a multimeter with its leads connected to the circuit, instead of a clamp meter.

FWIW, I remeasured with test leads and got 67 mA, so the clamp meter wasn't terribly off there, but it was off.

 

[JRH02]

TY so much for this tidbit. I have spent a BUNCH on batteries whether ATV, UTV, little or BIG B/H/loader, pickups and the most critical, a bank of eight 6v Trojan RE16-B's for the home solar. We are off grid for 10 years - I know about maintenance: watering, SGs, EQ, etc., etc. trying to stretch the life. Not only the life but the performance because if I can improve performance then the genset autofires less when voltages drop to "charge time" and then I'm buying fuel.

So, could you add some detail to this this comment? Is it with regard to the desulfator/charger combo, the stand alone desulfator?

I recently bought two 12vdc OBD desulfators to try on the small stuff. I'm experimenting. If it has value then it will be better, else worse or blah by next spring. If the BatteryMinder desultator works to even a moderate degree then the improvement to battery performance could be killer good.

Then after this experiment will be the 48vdc bank. THat will be interesting if it is worth the try.

Best, JRHill