Dang!

[deadlyapp]

Mindless hit it pretty well. A good maintainer should go into float at 13.7V for a deep cycle / standard lead acid battery. Nearly all of the battery maintainers on the market are cheap and have a very poor control circuit for float. Hearing the battery boil off is a good way to know its not floating correctly.

 

[Muse]

Anyone have knowledge, experience, opinions, etc. on the Harbor Freight #42292 Chicago 12volt Automatic Battery Float Charger (currently $6.99)?

I have 3 of these, two of them functional (one detached from the wall wart), one fully OK, one smashed, but AFAIK works.

I have the one that looks AOK on the battery now, because, like I said in my last post, the Schumacher seems to have lost its ability to sense a full charge and is evidently overcharging. The reviews at Harbor Freight for this super cheap presumably NOT a trickle charger but a FLOAT charger are uniformly positive, although I haven't seen anything from anybody who's evidently quite technically inclined.

On the front of the box it says, "Not a trickle charger..."

On the back of the box it says:

The Battery Float Charger is used for the maintenance of wet or gel-cell batteries that are stored or used periodically in such items as boats, cars, snowmobiles, ATVs, and tractors.

The Float charger prevents self discharge of the battery, while maintaining and extending the life of rechargeable 12 volt batteries. It maintains a battery charge for batteries rated from 5 to 125 amp-hours, by proving (I'm sure they meant providing) a 13.2 VDC Maximum output (bolding mine). Other types of chargers provide a strong, rapid charge but tend to boil out liquids and decay electrodes.

It is simple to use: Just hook it up, plug it in, and forget about it.

 

[Muse]

I'm suggesting that taking the charger off and measuring 12.97V, or especially with it still hooked up and reading 12.97V, isn't necessarily a sign of a problem, but after the charger is disconnected, and ideally disconnected from the vehicle too, for around 1/2 hour, then the battery should be settling down close to 12.6V and stay there if it's both good/viable and disconnected. If the battery stays as high as 12.9V after disconnected for 1/2 hour.... that's not supposed to be possible.

But in the maybe 10 years I've been using the Schumacher charger/maintainer I've never seen voltage reading using multimeters after removing the charger higher than 12.7v. That made me suspect that the Schumacher's gone bad. I could hook it up again and see if the red LED will light up.

 

[mindless1]

It's possible it has gone bad, but the behavior described is not unusual for chargers in general.

 

[Muse]

It's possible it has gone bad, but the behavior described is not unusual for chargers in general.

I'm wondering if I should cancel my order for the out of stock
BatteryMINDer 1500: 12 Volt-1.5 AMP Battery Charger, Battery Maintainer, and Battery Desulfator with SmartTECHnology - Designed for Cars, Trucks, Boats, Motorcycles, Snowmobiles, Jet Skis, Golf Carts

https://www.amazon.com/dp/B00D7HZ6FC?pldnSite=1

The Schumacher might be alright, just don't know. Also, the Harbor Freight #42292 float chargers have super high feedback from buyers, are said to deliver 13.2v, NOT be trickle charger but float charger. Figure I might be OK just using one of those. Ideas? TIA!

BTW, my alarm is continuing to work the last few weeks.

 

[mindless1]

^ Couldn't tell you what the best value is, but that $53 BatteryMinder seems overpriced for the purpose if you just need a float/maintainer. I'd sooner get the HF $7 one, but then right away, test and measure to see if it's doing what you want.

 

[Muse]

^ Couldn't tell you what the best value is, but that $53 BatteryMinder seems overpriced for the purpose if you just need a float/maintainer. I'd sooner get the HF $7 one, but then right away, test and measure to see if it's doing what you want.

I already have 3 of those HF ones. One looks and appears fine, seems to be working OK, although I didn't test it's terminals with a multimeter to confirm 13.2v. Another's guts (not the attached wall wart) had an accident and the casing is smashed and I had put plastic tape wrapped around as a DIY casing, but I think it works too. The 3rd is just the guts + clips, the leads to the wall wart having been severed. But it would probably work if attached to appropriate wall wart.

I may just cancel that $53 BatteryMinder before it ships. It has some negative reviews, indeed. I read around 150 reviews of the $7 HF float maintainer and couldn't find a single negative review. Well, one person said theirs failed in a month or something and they just bought a replacement, writing it off to "you get what you pay for." That's the worst I saw. Nobody said it overcharged their battery.

The HF is simple, easy peasy. No temperature sensitivity thing. I don't know what desulfator capability is or entails.

Edit: I cancelled that order for the BatteryMinder!