Battery charger help

[abunaitoo]

So many smart guys here.
I'm looking for help.
Hoping someone knows about battery chargers.
Husky HSK074HD auto battery charger.
Switch on charging........
I get 12vac coming out of the transformer.
I get 12vdc going to the board.
I only get 11.5vdc coming out of the battery connectors.
I'm sure it should be higher than 12vdc, at least.
Switch on starting...........
I get 14.5vdc at the battery connector.
Don't see anything burnt on the board.
But the red led, polarity warning, corroded off.
I was thinking that it doesn't have to be connected.
Just a warning light.
2amp or 10amp switch doesn't make any difference.
Any ideas????

[deltaenterprizes]

To test the transformer you need to disconnect it from the circuit, while connected there is a load on the transformer causing a voltage drop.
14.5 VDC is enough to charge a battery.
I have a golf cart battery charger that was putting out 36 VDC with a half wave rectifier and now that I put in a full wave rectifier it puts out 90 VDC!
I don’t know what to do with a 90 VDC battery charger!

[Scrounge]

To test the transformer you need to disconnect it from the circuit, while connected there is a load on the transformer causing a voltage drop.
14.5 VDC is enough to charge a battery.
I have a golf cart battery charger that was putting out 36 VDC with a half wave rectifier and now that I put in a full wave rectifier it puts out 90 VDC!
I don’t know what to do with a 90 VDC battery charger!

That should run a 90vdc PM or brushless motor just fine! Put a couple of filtering capacitors on the output, and see what you get for voltage then. Make sure they're rated for about twice the voltage you expect! Don't want to let the magic smoke out.

Bill

[Scrounge]

So many smart guys here.
I'm looking for help.
Hoping someone knows about battery chargers.
Husky HSK074HD auto battery charger.
Switch on charging........
I get 12vac coming out of the transformer.
I get 12vdc going to the board.
I only get 11.5vdc coming out of the battery connectors.
I'm sure it should be higher than 12vdc, at least.
Switch on starting...........
I get 14.5vdc at the battery connector.
Don't see anything burnt on the board.
But the red led, polarity warning, corroded off.
I was thinking that it doesn't have to be connected.
Just a warning light.
2amp or 10amp switch doesn't make any difference.
Any ideas????

I've got one of the automatic chargers, and won't buy another one. That said, you do want yours working. I'd start by getting that polarity light going. It may affect how much current the charger can put out, and the little computer that runs the charger may be looking for current flowing through that LED or not.

Bill

[jim 44-40]

[QUOTE=Scrounge;5553235]I've got one of the automatic chargers, and won't buy another one. That said, you do want yours working. I'd start by getting that polarity light going. It may affect how much current the charger can put out, and the little computer that runs the charger may be looking for current flowing through that LED or not.

Bill[/QUOTEjust typed in 12 volt battery charger schematics on web and clicked on images, I think Scrounge hit it on the money about the LED light.

[JonB_in_Glencoe]

maybe it's sensing your battery is defective

[DougGuy]

So many smart guys here.

Any ideas????

Yes. Stop shopping at Horrible Freight.

[georgerkahn]

So many smart guys here.
I'm looking for help.
Hoping someone knows about battery chargers.
Husky HSK074HD auto battery charger.
Switch on charging........
I get 12vac coming out of the transformer.
I get 12vdc going to the board.
I only get 11.5vdc coming out of the battery connectors.
I'm sure it should be higher than 12vdc, at least.
Switch on starting...........
I get 14.5vdc at the battery connector.
Don't see anything burnt on the board.
But the red led, polarity warning, corroded off.
I was thinking that it doesn't have to be connected.
Just a warning light.
2amp or 10amp switch doesn't make any difference.
Any ideas????

You should be getting MORE than 12 volts a.c. from your transformer output. A "simple plain Jane" battery charger -- I've made/used these for years! -- takes a 14 - 16 volt a.c. transformer output which inputs a full-wave bridge rectifier (basically four diodes to change your a.c. to direct current). As electric current passes through a diode/rectifier it's voltage is dropped from 1/2 to 3/4's of a volt... which still provides enough voltage -- hopefully on the 14.5vdc proximity -- to charge your battery.
Now... there are batteries and there are batteries. I ASSUME you're addressing lead-acid (e.g., the old, plain Jane car battery) battery here? Nowadays, varieties abound -- glass bedded, lithium ion, and... the new kid in the block: lithium ion phosphate. ALL of which require specialized charging equipment.
Back to YOUR charger, most have a "chip" inside which determines out vs in voltage, and IF this chip goes... no more charging. Regardless -- if you are accurately getting only 12 volts from the transformer -- imho it's time to invest in a new charger.
geo

[MaryB]

12 volt AC from the transformer is normal, fed to a full wave bridge that should give 16.8 volts to the charge board. May have a bad rectifier between the transformer and board... The rectifier will be attached to the case or a heat sink inside the case to dissipate heat...

14.5 volts dc is enough to float charge a lead acid car battery.

[waksupi]

While we are on the subject, what is the best battery charger you can buy?

[Scrounge]

Yes. Stop shopping at Horrible Freight.

Since just about everything you can buy in this country is made in China now, why go after HF? I've got an angle grinder here I bought from them at least 27 years ago. Think it may have been longer than that. Still runs. I don't like changing grinding wheels, so have several of them set up with grinding wheels, wire brushes, and flap sanders so I don't have to stop work to change to the one I want, and a $10 or $15 angle grinder is quite handy. Their hand tools are generally just fine, too. And they still honor their warranty, unlike Craftsman.

I have a Craftsman heavy duty battery charger/starter. The timer switch came unstuck years ago, but it still works OK if you monitor it. I mostly use it for electrolytic rust removal now. Guess what? It was made in China, too. Now it's only about 20 years old...

Bill

[Shawlerbrook]

I also am interested in waksupi’s question as my old one is over 30 year old and going to need replacement some time soon.i think it is a Schumacher and if they are still that reliable I will buy another.

[abunaitoo]

Friend got one of those fancy chargers with all kind of options.
It never did work.
Hook it up to charge and it goes into rejuvenate mode, then nothing happens.
That's why I'm working on his old charger.

[Head Shot]

I also am interested in waksupi’s question as my old one is over 30 year old and going to need replacement some time soon.i think it is a Schumacher and if they are still that reliable I will buy another.

Hello:
been a few years now but schumacher used craftsman electric battery chgr parts at that time also.
So if you need parts and schumacher doesn't have it then check craftsman battery chgr company.
If its not regulating the voltage it could be the mosfet style 12vdc regulator chip forget now without looking but thought it was a 798 chip id have to look in my parts bin that i repair motorola fm business band radio power supplies like the astron sl15r base converter unit.
And yes if the chgr in question has more than one diode and one or more went bad then expect lower output until the diode in question is replaced.
Id quess the bridge wave rectifiers likely fine since your getting a reading on the output of a dc wave sine not a/c at the battery cables.
Bear in mind that if a capacitor is going weak that it too can reduce output and if bad the capacitor is bad enough then the output will vary accordingly so check capacitors and output transistors.
Head Shot

[Shawlerbrook]

Luckily my old Schumacher is still going strong, but at 30+ years it’s just a matter of time. I wonder if the new ones are that good. On my ATV’s and tractor I have Battery Tenders and they seem to do the job as advertised.

[alfadan]

Most new chargers won't put anything out unless the battery is above 12volts already. I bought what I thought was a "dumb" charger, but still the same crap. I may use the transformer and make my own.

[Brassmonkey]

While we are on the subject, what is the best battery charger you can buy?

You won't find it on the shelf at a store but I've got a Dayton roll a long charger that weighs more than the batteries it charges. $60 8 years ago on Craigslist.

All these smart chargers don't last and are usually more trouble than they are worth.

[rbuck351]

I have an old Marquette Porta-Fast 6/12 charger that I suspect was made in the 50s or 60s. It is rated to 50 amps 12 volt output and 80 amps 6 volt. It's the type used in garages and service stations and still works great. If you could find one similar, you would be miles ahead of these modern chargers that seem only to work when they want to. My wife bought one of the new ones and it is a joke compared to the old Marquette.

My son bought a new charger ( garage type) from a parts store telling them he wanted a dumb charger and was assured that it was an old type. It wasn't and it only works when it chooses to.

[farmbif]

with any battery charger you spend your money on what might be important is the warranty and how the place you buy it from stands behind that warranty. I have a few that are all at least 20 years old so cant help out on what brand might be good. schumacher has been a big player in the battery charger game for quite a while.

[JonB_in_Glencoe]

I have an old car battery charger, maybe from 1970s?
I can't read the name on it anymore, so I don't know what brand?
I've replaced the power cord and battery cables more than once, and I replaced the little meter/guage once.
Still works great.

I do have a 'tender' type charger for motorcycle gel-mat type batteries.