Can i Charge a 12 V 130amp lead acid battery with a 31 volt printer adaptor

[sshazia2001]

What would happen if i try to charge a 12 volt 130 AH battery with a 31 volt printer adaptor.

also tell me what would happen if i suppliment my battery which is bieng charged by a ups with a 12volt 6 amp adaptor, i mean would that mean that i am now giving the battery 24 volts of charge, like 12 volts of the adaptor and 12 voltsby the ups.

[Soeren]

Hi,

What would happen if i try to charge a 12 volt 130 AH battery with a 31 volt printer adaptor.

That depends a lot on the adapter.
Either the impedance of the adapter is so suitably high that it will charge the battery (slowly though), or else the adapter may melt down (fire hazard!). A well selected lamp (light bulb) in series with the adapter is a very good way of preventing that.

What is the adapters max. current?
(And what else does the markings say?)

also tell me what would happen if i suppliment my battery which is bieng charged by a ups with a 12volt 6 amp adaptor, i mean would that mean that i am now giving the battery 24 volts of charge, like 12 volts of the adaptor and 12 voltsby the ups.

Not sure what you mean here?
If you put the UPS battery in parallel with the large battery, it would still be 12V.

The best way to charge a vented lead-acid battery is with a current of around C5 in around 7.5 hours (if totally flat), which in your case amounts to 26A. Charging with 6A will take around 30..35 hours and the lower the current the longer the time (obviously) but multiplied with a factor above 1.0, so it quickly becomes a real pain, if the battery is driven flat.
Also note that with lead-acid, you need marine/golf-cart batteries in order to drive them fully down on the discharge, as car type batteries don't like cyclic use.

Is it all about charging the 130Ah the cheapest way?
And if, what other options do you have available?

If you're good at electronics, an old PC supply could be modded to give a voltage of ~15V.
That would be the cheapest way to get a decent current.
Another way is to place it in te trunk of a car and charge it along with the existing battery, although it would take a little circuit to avoid the aux battery draining the starter battery.

[sshazia2001]

RED    +5 VDC   All red wires common to each other
YELLOW  +12 VDC  All yellow wires common to each other
WHITE -5 VDC Not Used
BLUE  -12 VDC  Not Used
ORANGE +5v Signal Wire* Power Good Lead, connect to +5 VDC
BLACK  Common Grd. All black wired common to each other

regarding pc power supply i got the above info from some website which i dont remember now. so how can i utilise this power supply to make 15 or 16 volts out of it to charge the 12 v 130 ah battery(lead acid).

[Pogertt]

Another way is to place it in te trunk of a car and charge it along with the existing battery, although it would take a little circuit to avoid the aux battery draining the starter battery.

How is putting a battery in the trunk of a car gonna charge it?
All I have ever found in the trunks of any cars I owned was a spare tire and a jack.

[Soeren]

Another way is to place it in te trunk of a car and charge it along with the existing battery, although it would take a little circuit to avoid the aux battery draining the starter battery.

How is putting a battery in the trunk of a car gonna charge it?
All I have ever found in the trunks of any cars I owned was a spare tire and a jack.

If you read all the words in what you quote, you might have stumbled over the "and charge it along with the...".
If you go to a custom car exhibit you'll be hard pressed not to see a lot of cars with the starter battery in the trunk (which admittedly is a bit looney), but if a car haven't got fat wires running to the trunk already, it's quite easy to install them.
But you have my empathy, I used to have a car like yours too, but obviously, I didn't keep it for long.

Did you have any constructive words to help the OP, or have you just decided to play the child that cannot quite reach the cookies?

[Soeren]

Hi,

RED    +5 VDC   All red wires common to each other
YELLOW  [...]
regarding pc power supply i got the above info from some website which i dont remember now. so how can i utilise this power supply to make 15 or 16 volts out of it to charge the 12 v 130 ah battery(lead acid).

To raise the output to around 15V, you need to modify the feedback voltage in the circuit and, depending on your luck in finding a good PSU to use, may need a rewind of the output transformer (increasing the secondary winding by around 25%), hence the "If you're good at electronics, [...]"

If you don't know the inside of a PC PSU, don't attempt this, as they contain high voltages, even for a while after unplugging.
If you have a schematic over the PSU, please post it and I'll have a look at it.

[sshazia2001]

i am not at all good at electronics, seems to me that i have to buy a 16 volt charger. Thank you soeren , your posts were very informative.. one more question comes into my mind. When i shake my battery and then remove the caps from the six cells, the acid inside the battery is sort of dirty greyish, the grey particles then settles after some times.

what are these and would they remain in the acid for ever of should i change the acid of the battery?

[Soeren]

Hi,

i am not at all good at electronics, seems to me that i have to buy a 16 volt charger.

That will probably be the safe solution and speaking about safety...
Always connect the battery to the charger before plugging the charger into the mains and remove it from the mains before unplugging the battery.

The reason for this is, that the battery releases oxyhydrogen when charging and this is extremely explosive. Removing a current carrying wire will create sparks and can make the battery explode (and spray melted lead and acid in the process). A well ventilated place should be used for charging for the same reason.
Don't charge with the caps on, in an attempt to minimize the gas, as that could cause an "explosion" (or rather a rupture) as well.

When i shake my battery and then remove the caps [...]

Just trying to forget your gender here 

[...] from the six cells, the acid inside the battery is sort of dirty greyish, the grey particles then settles after some times.

what are these and would they remain in the acid for ever of should i change the acid of the battery?

The grey sludge is lead sulphate and is a sign of the plates deteriorating (it cannot be put back into the plates). I don't know why you shake your battery and you should stop such behavior immediately, as the sulphate should be left at rest at the bottom as far as possible.

If the sludge reaches the plates, it will partially shunt the plates and more or less discharge the battery, making the apparent capacity lower. In that case, measure the acid weight (concentration) like when checking the charge level of a car battery and mix up new demineralized water/sulfuric acid to the same weight (use the same measuring gizmo). Always pour the acid into the water, not the other way around (as the latter would make it "explode", bathing you in acid).

Then get some help, as a 130Ah battery is heavy (but you already know that), to empty the battery acid into something that can safely hold it, flush the battery with demineralized water once or twice to get the rest of the sulphate out and pout the newly mixed water/acid to the proper levels on the battery - this should all be done in one go, as the plates shouldn't be left to dry out completely  (or they will be damaged). Get rid of the used/polluted acid in a sensible way.

Don't be tempted to "improve" the capacity by using a more concentrated water/acid for the cells, as the battery manufacturers have already found the best compromise between capacity and lifetime (the more acid the solution is, the faster the lead plates deteriorate).

Always be careful around acids and keep some soda or similar alkaline stuff at hand to neutralize the acid, for the unfortunate event of acid splashes on skin, clothes or generally on surfaces that are not acid proof (I have a monkey suit that looks like it was shot repeatedly with a shotgun, solely from minute and invisible acid sprays - even a weak acid will sit and work its nefarious ways until next time in the laundry, where it will reveal the damages as the weakened spots gets a workout in the washer and vanish, leaving only little holes.

This cleansing is only needed if the grey sludge is actually shorting out the plates though, otherwise just leave it resting at the bottom.

[Daanii]

Excellent information, Soeren. It sounds like a regular car battery charger would work to charge this 12 Volt battery. I have one in my garage that I have not used for many years. I suspect many others do too. So if you do not want to buy one, you could probably beg, borrow or (preferably not this last) steal one.

I don't mean to hijack the thread. But you mentioned not leaving the caps on when charging. Are the caps supposed to be removed when charging?

Also, when charging a deep discharge 12 Volt lead-acid battery, I sometimes hear some bubbling sounds. Is this unusual, or dangerous? I do make sure that the space is well-ventilated.

[Soeren]

Hi,

It sounds like a regular car battery charger would work to charge this 12 Volt battery. I have one in my garage that I have not used for many years. I suspect many others do too. So if you do not want to buy one, you could probably beg, borrow or (preferably not this last) steal one.

Perhaps. I do have a ~20kg charger that can handle the largest lead-acids, but a lot of the so called hobby-chargers are very optimistic in their ratings. I've seen chargers sold as 10A chargers that wouldn't even give 3A under the best conditions, but on the other hand , some of the newer few-hundred-gram switching chargers might be worth their ratings - but I don't have any first hand experience with those.

I don't mean to hijack the thread. But you mentioned not leaving the caps on when charging. Are the caps supposed to be removed when charging?

on the non-sealed types yes (at least that's what I've learned) and they can gas a lot when charged with a cheap charger (i.e. if it's a little high on the voltage, which is not good for the battery either).

Also, when charging a deep discharge 12 Volt lead-acid battery, I sometimes hear some bubbling sounds. Is this unusual, or dangerous? I do make sure that the space is well-ventilated.

Unless the battery is made for it, it's slow murder to deep discharge (but who's in a hurry )

Gassing to some extent (small bubbles) is normal when charged or discharged with a relatively high current and near the EoC when charging for cyclic use (which needs slightly higher voltage than float charging). As long as the bubbles are small (<3..4mm or so in diameter) this is normal behavior and no cause for alarm, but if it's close to boiling with large bubbles, something's wrong (so check the terminal/charge voltage).

Also note that this bubbling will throw tiny acid drops everywhere within 20..30cm or more from the battery, so place it far from sensitive stuff and when the caps are back on, wiping it down with a hard wrung cotton cloth that was dipped in soda-water. This neutralizes the acid and saves on overalls, but keep the soda from entering the inside of the battery,or it will ruin it.