Sodium Sulfate lead/acid extender

[FensterKarton]

http://members.shaw.ca/Craig-C//Na2SO4.html
It's been reported that Interstate put sodium sulfate in their Optima batteries (originally designed by Hot-Rod Magazine in about 1990). But evidently they have stopped using it: At an electric car company, I learned that some "prototype" Optima batteries had lasted 5 years in daily electric vehicle (EV) use. Optima batteries delivered later lasted only "the usual" 1 to 1-1/2 years.

I also heard it was used during WWII.
Anyone here try it?

 

[advancedelectricbikes]

There are a few methods of increasing the life of lead acid batteries. Putting additives in the electrolyte is not one of them.

A well-designed high-power desulfator will remove PbSO4 from the plates. The PbSO4 will be reconstituted in the electrolyte.

Another method, used on Allied submarines during WWII, is to slowly and totally discharge the batteries every six months, reverse the polarity, and recharge them. They will last many years using this method.

 

[999zip999]

My friend hooked up a 12v in a bug backwards and it worked so my teacher told me to leave it. So a battery is ok to use backwards ?

 

[amberwolf]

If you don't mind blowing up anything attached to the circuit that is polarity sensitive, sure.

Also, probably bad things will happen when you try recharging it that way (like when you run the engine and the alternator or generator is spinning).

 

[advancedelectricbikes]

My friend hooked up a 12v in a bug backwards and it worked so my teacher told me to leave it. So a battery is ok to use backwards ?

He should reverse the connections. However, as an interesting aside, a lead acid battery will sometimes spontaneously flip polarity. If it does, you should clearly mark the new polarity on the terminals and reverse the connections to the battery terminals.

 

[dogman dan]

That teacher sounds dumb to me. I can see how the starter would still work with polarity wrong, but not how the alternator would. Pretty simple stuff on old bugs all right.

 

[bzhwindtalker]

Starters are series-wound motors (mo magnets), they will always spin in the same direction.
On a very old car, there is not a lot of electronics to go wrong anyway

 

[liveforphysics]

My friend hooked up a 12v in a bug backwards and it worked so my teacher told me to leave it. So a battery is ok to use backwards ?

He should reverse the connections. However, as an interesting aside, a lead acid battery will sometimes spontaneously flip polarity. If it does, you should clearly mark the new polarity on the terminals and reverse the connections to the battery terminals.

Umm...

 

[999zip999]

I think the battery was low or dead and was charged that way then hook up ? It was at Golden West College and the theacher own a eleltric auto shop ? Marv's something. Oh yea over easter he was stealing diseol engines out the back door of the school and got fire. sold his shop. Then 2 weeks later I found him on the side of the road above Reno looking at land for a new home. Small world

 

[Punx0r]

I assume reversing the polarity is something to be done on a healthy battery, and won't work on a dead one?

 

[advancedelectricbikes]

My friend hooked up a 12v in a bug backwards and it worked so my teacher told me to leave it. So a battery is ok to use backwards ?

He should reverse the connections. However, as an interesting aside, a lead acid battery will sometimes spontaneously flip polarity. If it does, you should clearly mark the new polarity on the terminals and reverse the connections to the battery terminals.

Umm...

I know, I know, Luke. But there seems to be a lot of anecdotal evidence of lead acid batteries spontaneously reversing their polarity, especially after sitting unused for a while:

http://www.modelboatmayhem.co.uk/forum/index.php?topic=6677.0

http://www.carkb.com/Uwe/Forum.aspx/gmc/11173/Battery-reversed-polarity

http://leadacidbatterydesulfation.yuku.com/topic/1038/Reversed-polarity-cell#.T9VABn6ixwE

http://www.ssbtractor.com/antique-farm-lawn-garden-tractors/2009/01/6-volt-battery-polarity-reversed/

 

[liveforphysics]

You can charge them either way if you go through formation backwards, but they don't reverse magically on there own. People have some parasitic load on a battery that has at least 1 cell in better health than the others (like almost every used battery). The little parasitic load overtime discharges the string, the lowest capacity cells reaching zero first and getting reverse charged (actually changing the formation of lead oxide and sulfate on the plates to have really swapped which terminal is positive and which is negative), then the next lowest capacity cell joins the reversed club, then the next, and the next etc, until a voltage equilibrium is reached under that load between the still correct polarity highest capacity cell in the string and the other reversed cells, so the net string voltage is roughly 0v while connected to that little parasitic load.

Remove the load and let the cell sit open-circuit, the chemistry of the cells will float up ~1.5v/cell (0% SOC open voltage), you have 4-5 reversed cells and 1 correct cell, you get a voltage of perhaps 6 to 8volts, with reverse polarity.

 

[advancedelectricbikes]

You can charge them either way if you go through formation backwards, but they don't reverse magically on there own. People have some parasitic load on a battery that has at least 1 cell in better health than the others (like almost every used battery). The little parasitic load overtime discharges the string, the lowest capacity cells reaching zero first and getting reverse charged (actually changing the formation of lead oxide and sulfate on the plates to have really swapped which terminal is positive and which is negative), then the next lowest capacity cell joins the reversed club, then the next, and the next etc, until a voltage equilibrium is reached under that load between the still correct polarity highest capacity cell in the string and the other reversed cells, so the net string voltage is roughly 0v while connected to that little parasitic load.

Remove the load and let the cell sit open-circuit, the chemistry of the cells will float up ~1.5v/cell (0% SOC open voltage), you have 4-5 reversed cells and 1 correct cell, you get a voltage of perhaps 6 to 8volts, with reverse polarity.

Very interesting. Excellent explanation!

 

[advancedelectricbikes]

I assume reversing the polarity is something to be done on a healthy battery, and won't work on a dead one?

Not necessarily. About 80% of "dead" lead acid batteries have heavily sulfated and/or dendrited plates. The preferred method of revival is to desulfate the battery with a high-quality desulfator. After the battery is desulfated, SLOWLY and totally discharge it with a small load, such as an auto headlight. After the battery is totally discharged, charge it with reverse polarity. Make sure that you clearly remark the terminals with the new polarity. This method works best with deep discharge lead acid batteries.