Battery Charger Testing Results

[f355spider]

I was talking about those super cheap harbor freight chargers maintainers as that's what I thought you were referring to. I actually trust those more than my larger chargers as they don't have enough current to boil the batteries easily at 13.4-ish volts.

Admittedly, only a very few brands of battery tenders/chargers offer temperature compensation. I'm uncertain it is a "must have" feature, but it certainly doesn't hurt. My Pulse Tech and two each, Granite Digital "save a battery" battery tenders do not have temperature compensation...only my four Battery Minder brand. But the feature can prevent overcharging in hot weather and under charging in very cold weather. But even in "mild" Seattle, I can get temps in the upper 20's in winter in my garage and I can monitor the float voltage creep up to 14vt and drop below 13vt went it is over 100F

 

[pasadena_commut]

But even in "mild" Seattle, I can get temps in the upper 20's in winter in my garage and I can monitor the float voltage creep up to 14vt and drop below 13vt went it is over 100F

Today the temperature range from the weather service is 64F to 93F. However, the Prius 12V is below the cargo deck in the rear of the car, and even with all the windows open, with the car parked in direct sun in the driveway, the 12V would see something more like 70F to 110F. The Battery Tender Jr. isn't temperature compensated, and even if it was, the convenient spot to attach it as at the jump point under the hood. This makes charging the 12V during the summer problematic. Probably I should do it only at night where the temperatures are more modest and much closer to 70F than during the day. However, I don't like leaving a live 120V extension cord, or the hood open, unattended overnight in the driveway.

It would be a little easier in the garage, where the whole car would be close to the ambient temperature within that volume, so that temperature compensation could apply even without a sensor right on the battery. Unfortunately clearing out enough space to put a car in there would require the services of both Hercules and a divorce lawyer.

 

[f355spider]

Today the temperature range from the weather service is 64F to 93F. However, the Prius 12V is below the cargo deck in the rear of the car, and even with all the windows open, with the car parked in direct sun in the driveway, the 12V would see something more like 70F to 110F. The Battery Tender Jr. isn't temperature compensated, and even if it was, the convenient spot to attach it as at the jump point under the hood. This makes charging the 12V during the summer problematic. Probably I should do it only at night where the temperatures are more modest and much closer to 70F than during the day. However, I don't like leaving a live 120V extension cord, or the hood open, unattended overnight in the driveway.

The jump connections on one of my BMWs is located under the hood, and I'm not going to repeatedly open the hood to charge the car (I've replaced the hood cable on one of my BMWs twice over the past 20 years, lesson learned). My solution was the lengthen the ring terminal/SAE plug and run it up to the windshield wiper opening on the passenger side. Now I can plug in anytime I want, very easily.

I also purchased a 20ft SAE extension cord that runs under my garage door out to the driveway.

 

[repairman54]

I pulled my 2011 Delco battery off its BatteryMinder yesterday to put into my pop up camper to power its lights. Yes 2011 factory battery from my old Tahoe. I pulled the battery out of it in 2016 as not to trust it for sub zero winter starts when up north snowmobiling.
Put an Odyssey in it, truck has since been traded in back in '23. Delco battery sticker says 6 yr. on it.
Put my HF resistor pack style load tester on it out of BITOG curiosity and it still read 600 amps. After the load test voltage was at 12.65.
I pried open the cell caps, levels were just a hair over the plates, topped off with distilled water and into the camper it went for its once a year trip.
IMO the BM maintainer / conditioners are the best for the money, hands down. 1A and 1.5A temp. comp. units I've gotten from Northern Hyd. on sale.
I am dumbfounded that this battery is still hanging in. Yes its on the BM 24/7 for 359 days a year and its seen zero temps in the garage for the last 2 years.