12 volt battery overcharged to 24 volts
- Thread starter ryanmohr
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WOW, You guys do not want to go into mechanics
As Ross said, chemically impossible to get 24 volts out of one battery.
Take all the wires off all the batteries and test each again SEPERATELY.
"doubling up" means what?
+ on one battery to - on the other and the charger connected to the two open terminals????? (more accurately called series)
or
+ to + and - to - and the charger connected over one of the + and one of the - terminals???? (more accurately called parallel)
Until you can confirm that each battery is showing 24 volts I gota believe you have series 12+12=24 connected the batteries. If you have a single battery showing 24 volts call Ripley's s right away cause you have a gold mine as you have achieved what no one else in the universe ever has.
As Ross said, chemically impossible to get 24 volts out of one battery.
Take all the wires off all the batteries and test each again SEPERATELY.
"doubling up" means what?
+ on one battery to - on the other and the charger connected to the two open terminals????? (more accurately called series)
or
+ to + and - to - and the charger connected over one of the + and one of the - terminals???? (more accurately called parallel)
Until you can confirm that each battery is showing 24 volts I gota believe you have series 12+12=24 connected the batteries. If you have a single battery showing 24 volts call Ripley's s right away cause you have a gold mine as you have achieved what no one else in the universe ever has.
It is IMPOSSIBLE for a 12V lead-acid (or gel-cell) battery to read 24 volts..At around 16 volts, under heavy charge, the battery would be badly overheated and if you persisted charging it, it would destroy itself before it reached 24 volts. A fully charged, cool, new, 12 volt battery not under charge or load will read 13 volts, tops...
Alright guys, we can put an end to this once and for all. Turns out I'm just an idiot. I had been testing some of the shore power outlets installed on the boat and had forgot to switch over to DC when I checked the batteries. The fact that it came out almost exactly to 24 made me jump to conclusions instead of checking the basics first.
Batteries and charger are fine and charge is in the high 12s -- when I use the correct voltage settings that is
Batteries and charger are fine and charge is in the high 12s -- when I use the correct voltage settings that is
Exactly, Ross .. cockpit error.. One of those is spectacular.. the one where I had the D ten T set to AMPERES.. and thought I was going to measure volts.. some arcs and smoke and a very embarrassed operator! The Navy chief that was instructing didn't cut me much slack !
Inexpensive meters generally measure AC voltage by rectifying it first so yes, you can usually read DC on an AC meter.
C'mon guys we talking cheap here.. My digital from HF.. ws $2.99 on sale .. It says 26.2, if measuring on the AC setting, a 12 volt battery not connected to anything.. On DC scale it says 12.3 .. It is a great meter for knocking around .. I have a real meter that I use when measurements are critical..
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The cost of the part which allows the meter to actuallly measure AC is about 0.1 cent (ie, .001 USD) to the manufacture (a capacitor). Those meters are also only accurate to maybe +/- 10%.
But.. its pretty much the same as the POS I have stashed somewhere on the boat (I think I know where it is) and I can debug 95% of the problems with this meter.
But.. its pretty much the same as the POS I have stashed somewhere on the boat (I think I know where it is) and I can debug 95% of the problems with this meter.
I asked a friend who knows a lot about batteries about the maximum voltage that could be read and here is his reply:
While charging hard, just before the explosion when the case melts
allowing the plates to short, you can get it up to about 17-18V.
But, as soon as the overcharging current is removed, the cell voltage
quickly returns to around 14-14.5VDC on 6 cells that haven't shorted
and are still filled with some semblance of electrolyte..
As the plates will surely be warped by the heat softening the
normally soft lead, and the electrolyte boiling off the diluting
water as gas, spoiling the electrolyte's composition, these
overcharged cells should immediately be replaced before leaving the
dock. Warped plates could easily cause an explosion when pounded in
the waves, which would destroy the interior of the boat, not just the
batteries. Anyone caught asleep in the boat when the batteries blow,
in a case or not, will be breathing sulphuric acid vapors and burned
with the mist an explosion creates quite badly.
Batteries are too cheap to take that chance. The only way I know of
to get 6 cells to read 24VDC is to put a 24V charger on them with one
cell so boiled dry it finally acts like an open circuit. The
charging current on 6 cells at 24VDC would be way more current than a
boat charger could create unless the cells have very high internal
resistance. or his meter is toasted.
Doesn't matter....all new batteries are in order. Replace the lot
and properly charge SLOWLY for a day, discharge the cells back to
12.5 V then immediately recharge SLOWLY for a day...repeat the
process 3 times to soften the new plates with the proper
cycling....do a final recharge and she's ready for sea.
While charging hard, just before the explosion when the case melts
allowing the plates to short, you can get it up to about 17-18V.
But, as soon as the overcharging current is removed, the cell voltage
quickly returns to around 14-14.5VDC on 6 cells that haven't shorted
and are still filled with some semblance of electrolyte..
As the plates will surely be warped by the heat softening the
normally soft lead, and the electrolyte boiling off the diluting
water as gas, spoiling the electrolyte's composition, these
overcharged cells should immediately be replaced before leaving the
dock. Warped plates could easily cause an explosion when pounded in
the waves, which would destroy the interior of the boat, not just the
batteries. Anyone caught asleep in the boat when the batteries blow,
in a case or not, will be breathing sulphuric acid vapors and burned
with the mist an explosion creates quite badly.
Batteries are too cheap to take that chance. The only way I know of
to get 6 cells to read 24VDC is to put a 24V charger on them with one
cell so boiled dry it finally acts like an open circuit. The
charging current on 6 cells at 24VDC would be way more current than a
boat charger could create unless the cells have very high internal
resistance. or his meter is toasted.
Doesn't matter....all new batteries are in order. Replace the lot
and properly charge SLOWLY for a day, discharge the cells back to
12.5 V then immediately recharge SLOWLY for a day...repeat the
process 3 times to soften the new plates with the proper
cycling....do a final recharge and she's ready for sea.
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