Charging a 6 volt battery. Need Help

[RTR]

I've got 2 battery chargers that are identical and I have 2 6 volt batteries that haven't been used in about a year. They are dead and need to charge them to see if they're good. What setting will work best for this ? I noticed that the 6 volt setting is 40 Amps and 100 amp start boost. Wouldn't this be too high to charge a 6 volt battery when it's completely dead?? I checked each battery with a meter and with the charger disconnected they are reading around 5.5 volts. With charger hooked up they are reading around 9 volts.

 

[old]

Not likely to hurt either battery if they are good. Charge them for around an hour then check them. At first with a battery that discharged the charger will push more volts but as the voltage of the battery goes up the charger will slow down how many volts are being pushed into them

 

[Charles in Aus.]

Hook the two of them in series [ making 12 volts ] then charge them still wired together as for a six volt battery for an hour to establish a base voltage . Once there is some juice in them charge them singly .

 

[guido]

HELLO RTR,

That is way to much voltage for a 6 volt battery Looking at your charger, there is no function to charge a 6V battery, just a boost function.

You need a second 6V battery so you can use that charger. Connect them in series, and use the 12V maintenance function. You need to charge the battery at that level of charge very slow, until the voltage comes up close to 6 volts.

Then a 10Amp rate will finish the charge. Make sure all of the cells have enough electrolyte to cover the plate. You can add distilled water to cover them. After it is fully charged, you can the add to the cells just below the filler hole.

Keep an eye on the voltage during the charging process, so you will know when to stop charging. A fully charged 6V battery should be 6.3V at 85 degrees F*,

Guido.

 

[John T]

Looks like the charger has a 6 volt setting, the very first one right???

9 Volts is high for charging a 6 volt battery, I prefer more like 6.5 to 7+ depending on battery and charger capacity and its quality. Did you have it set on 12 volts across a single 6 volt battery perhaps????

Its possible to connect the two 6 volt batteries and charge both at once in series using the chargers 12 volt setting

I FIRST insure electrolyte is above the plates. If you charge them one at a time OF COURSE use the 6 volt setting DUH

If you choose to charge BOTH at same time in series using a 12 volt charger setting, I would start out at the low rate and after she starts drawing charging amps maybe for 15 to 20 minutes or so I would bump it up to a mid charge rate but then (only if needed I don't like too high of a charge rate) to high charge for a short time BUT DO NOT OVERCHARGE IT OR TOO FAST TO AT TO HIGH A RATE WHERE ITS BUBBLING AND OUTGSASSING BADLY. I like a longer slower low to mid charge rate versus a high charge myself EVEN THOUGH SURE IT TAKES MORE TIME but I prefer and advise a lower to mid rate myself...??..

NOTE one disadvantage of charging BOTH in series at 12 volts is if one is bad the other isn't gonna get charged correct IT MAY BE BEST TO CHARGE ONE AT A TIME ON THE 6 VOLT SETTING.

Check water level,,,,,,,,,,,,,start at a low rate,,,,,,,,,,dont charge too fast or at too high a rate

NOTE a full charged 6 volt battery stabilized and at rest should read around 6.3 volts and again I like to charge one at 6.5 to 7 or so NOT 9 or 10 volts as plates may be damaged if too long at too much voltage

Let us know

John T

 

[RTR]

(quoted from post at 01:45:09 10/22/18) HELLO RTR,

That is way to much voltage for a 6 volt battery Looking at your charger, there is no function to charge a 6V battery, just a boost function.

You need a second 6V battery so you can use that charger. Connect them in series, and use the 12V maintenance function. You need to charge the battery at that level of charge very slow, until the voltage comes up close to 6 volts.

Then a 10Amp rate will finish the charge. Make sure all of the cells have enough electrolyte to cover the plate. You can add distilled water to cover them. After it is fully charged, you can the add to the cells just below the filler hole.

Keep an eye on the voltage during the charging process, so you will know when to stop charging. A fully charged 6V battery should be 6.3V at 85 degrees F*,

Guido.

I was thinking it was too much voltage for charging them from dead too. The newest battery (bought in '13) was used to start a tractor 4 times and the tractor sat. IT actually stated bubbling water out of the top so I stopped charging it and went and got a new battery. $100 bill at the local tractor supply. Wish I could have gotten the old one to work. Oh well

 

[RTR]

John, I charged the batteries (seperate identical chargers) on the 5 volt setting (40 amp/100 amp start)

 

[guido]

HELLO John T,

First setting on the charger is a boost function, AS I told him, way too high for a 6V battery! The first setting is for boosting only! 40 amps for 6V and 100 amps for 12 volts.

That is why I also suggested two 6 volt batteries in series and start the charging process with the second setting on the charge, which is a maintenance charge, one to two amps or so,

Guido.

 

[John T]

I take it you meant or mis typed at the 6 volt setting. If you're like me my fingers get ahead of my old brain grrrrrrrrrrr

Thanks for the feedback

John T

 

[old-9]

When I have a battery that is very low on charge and I hook up the charger it usually pegs the meter on the charger. I hook a 12 volt light bulb in series for a few hours or overnight then hook the charger straight to the battery. This will give the battery a "soft" charge if it is shorted or froze. I use a 12 volt test light for the series hook up. joe
like this

 

[RTR]

(quoted from post at 02:37:52 10/22/18)
John, I charged the batteries (seperate identical chargers) on the 5 volt setting (40 amp/100 amp start)

I meant to say it was on the 6 volt setting. Darn phones.

 

[MarkB_MI]

Most battery chargers do not regulate either voltage or current, and I'm pretty sure yours does not regulate either one. The switch settings merely select different transformer taps, giving different voltages. The "6 volt" setting is just the one that produces the lowest voltage, and that's the one you want to use.

The current value for each of the switch settings is just a nominal value, based on what you can expect the charge rate to be with a partially-discharged battery. You've no doubt noticed the current drops as the battery charges. That's because the output of the charger is not a constant voltage but rather a full-wave rectified AC. Consequently the diodes conduct only when the voltage of the rectified AC output exceeds the battery's voltage. The duty cycle that the diodes are forward-biased drops as the battery charges, and eventually the current drops to almost zero.

 

[John T]

I suspected that lol

John T

 

[pinball]

I have found that batterys will only take so much charge depending on how low they are. if your 6 volt battery is taking 9 amps then its not dead but very low. you can use your charger but you will need to watch it closely as to not over charge it. I have a charger just almost like yours but rarely use it unless I am I a hurry. I have a smaller charger that has 6/12 volts 2/6 amp charge on it and an automatic shutoff when voltage in the battery is correct. I normally use the 2 amp trickle charge. to me the slower you charge your battery the longer it will last. I use my charger during the inactive months of fall/winter to keep them fully charged. my lawn mower battery is 5 years old and still going strong. I have 3 other battery's that are 6 years old and still going strong. use to not care so much about batteries but the price of them has changed my mine. if you have your caps off when charging especially in a boost mode you should see each cell bubbling some. the ones that dont are probably dead. to long of a boost will destroy a battery and I have read tales where they blew up so be careful when you use it. good luck.

 

[RTR]

(quoted from post at 17:27:08 10/22/18) too long of a boost will destroy a battery and I have read tales where they blew up so be careful when you use it. good luck.

Just curious.....what is considered too long of a boost??