Battery / Solar Question

DaveInDenver

Expedition Leader
Is it worth, adding sulphuric acid back into them? Providing one can even get any?
It's been a while since I've had to buy it but you used to be able to get a bottle of "battery acid" from any NAPA. Then you may need a hygrometer for testing specific gravity and distilled water if it's not already pre-diluted. They also make battery acid filler bottles which make topping the cells easier.
 

luthj

Engineer In Residence
You can buy electrolyte (acid) at some auto parts stores, or at battery distributors. Some batteries are shipped dry, and filled/charged at the store. You need to fully charge and measure the specific gravity (SG) of the good battery and compare it to the one that may have leaked. Or if both batteries have lost a fair bit of electrolyte, you may need to contact the MFG to see what SG they used. Then you can find the correct electrolyte. One located you can empty the battery, and refill with fresh electrolyte. Do not let the batteries sit for long empty.
 

Pacific Northwest yetti

Expedition Medic
It's been a while since I've had to buy it but you used to be able to get a bottle of "battery acid" from any NAPA. Then you may need a hygrometer for testing specific gravity and distilled water if it's not already pre-diluted. They also make battery acid filler bottles which make topping the cells easier.
Good to know, thanks!

I have two Trojan T-145+ 6 volts- After buying the camper used I noticed what seemed like poor battery life for 280/amp hour. When I checked them, the caps were on solid- however the tops of the plates had dust on them........and almost no water. I added almost a gallon to each. Which helped, I was wondering if i should go through this process or not. Thank you for letting me pick your brain.
 

dwh

Tail-End Charlie
DWH- Its been plugged in the past month since I was in Patagonia, will that be enough or do I need to - use/discharge/ plug back in ?
Just being plugged in doesn't do anything to recover the batteries unless the charger has a built-in EQ function (and the EQ function is enabled). Just sitting around at float voltage won't do it.

Equalize is "a timed, controlled overcharge". Fully charge the battery, then raise the voltage (how high depends on who made the battery, usually somewhere over 15v) and hold it there a specific time.

This helps to dissolve lead-sulphate crystals on the plates and also stirs the electrolye by making it bubble vigorously. The stirring eliminates stratification (acid and water separating into layers).

Of course the bubbling is caused by electrolysis separating water into hydrogen and oxygen, so the batteries need to be topped off after an EQ.

Desulphators (usually standalone units, but built into some battery chargers (very few - Battery MINDer (not Battery Tender) is one)) pulse a small current into the battery at a frequency designed to breakup lead-sulphate crystals grown too hard to be broken down by an EQ cycle. Desulphation takes weeks to show any improvement, and can take months to finally reach full effect.


There never was any recommended battery maintenance procedure that required discharging the battery...

...but that's changed in recent years. A few sealed AGM batteries such as Odyssey do now have a procedure that requires discharging then recharging with a high amp charger. Only applies to those specific batteries though...not to yours.
 

Pacific Northwest yetti

Expedition Medic
Just being plugged in doesn't do anything to recover the batteries unless the charger has a built-in EQ function (and the EQ function is enabled). Just sitting around at float voltage won't do it.

Equalize is "a timed, controlled overcharge". Fully charge the battery, then raise the voltage (how high depends on who made the battery, usually somewhere over 15v) and hold it there a specific time.

This helps to dissolve lead-sulphate crystals on the plates and also stirs the electrolye by making it bubble vigorously. The stirring eliminates stratification (acid and water separating into layers).

Of course the bubbling is caused by electrolysis separating water into hydrogen and oxygen, so the batteries need to be topped off after an EQ.

Desulphators (usually standalone units, but built into some battery chargers (very few - Battery MINDer (not Battery Tender) is one)) pulse a small current into the battery at a frequency designed to breakup lead-sulphate crystals grown too hard to be broken down by an EQ cycle. Desulphation takes weeks to show any improvement, and can take months to finally reach full effect.


There never was any recommended battery maintenance procedure that required discharging the battery...

...but that's changed in recent years. A few sealed AGM batteries such as Odyssey do now have a procedure that requires discharging then recharging with a high amp charger. Only applies to those specific batteries though...not to yours.

Thank you guys, for walking me through what I did not know! One of the great things about this forum. Sorry for hijacking the thread a little,
 

john61ct

Adventurer
A battery with reduced capacity can be restored to some extent, but the damage to its overall longevity has been done.

Industry standard is to replace a bank when SoH drops to 80%. For non-critical use, pushing to 70% maybe even 60% is common, but odds are increasing of "unexpected sudden failure" events.

Equalizing is best used on a regular basis to **prevent** sulfation problems, the worse your PSOC abuse the more frequent. Under proper care, once a month is enough.

I have yet to see any objective report from a source I trust showing that "battery desulfators" are anything but snake oil.
 

luthj

Engineer In Residence
Filling a battery with distilled water instead of electrolyte and performing an equalize charge until specific gravity no longer rises. Followed by refilling with the correct electrolyte can remove heavy sulfation . This approach is often used on badly sulfated forklift batteries. The reason this works is because lead sulfate is much more soluble in distilled water than normal electrolyte.
 

dwh

Tail-End Charlie
I have yet to see any objective report from a source I trust showing that "battery desulfators" are anything but snake oil.
I was the same. I searched and searched...nothing but anecdotal reports and manufacturer claims. (Google is actually a crappy search engine because it tries to predict what you want and the prediction is deliberately biased to bring in ad revenue.)

Then I did eventually find some evidence. It's been at least 5 years and I don't recall the exact sources, but I think one was some paper from some university guys, and the other from a manufacturer. Both tore into the batteries they were testing to examine the actual sulphation on the plates and saw measurable improvement.

Because of that, I bought a Stanley branded 15a smart charger (same one is available with Black and Decker branding) that had a desulphation function (that they call recondition).

https://www.stanleytools.com/products/automotive-tools/other-tools/battery-chargers/15-amp-battery-charger-with-quick-start-timer/bc1509

I tried it out on an old dead battery that I had sitting around for a core. It was a pain because the recondition function is on a 24hr timer. But after a few weeks charging, resting, measuring, reconditioning, discharging, etc., rinse and repeat...

That dead battery did show measurable improvement. IIRC, at first it wouldn't go above 10.4v, but after a few weeks it finally got to 11.4v. It topped out there and never went any higher, but nevertheless, for a battery that old and used up, it was enough to finally convince me that desulphation is worth doing.
 

dwh

Tail-End Charlie
AGM. no mess, no fuss, cant freeze. Trojan makes great batteries.
And wears out sooner and costs more. That "can't freeze" is nonsense - AGMs use acid/water electrolyte like all lead-acid batteries.

And yes, Trojan makes great batteries.
 

PV Hiker

Observer
I can see a majority of batteries just sit around like in a solar array or vechicles that don't move very often and can see a desulphation function is important. I read that AGM batteries it is not recommended to equalize.

Would you say that a battery in a vechile traveling say down a washboard road while the alternator is charging, would this vibration act as a desulphation function enough to limit the growth on the plates? I guess only if the vehicle was regularly driven with enough vibration would replace a desulphation function on a charger system?
 
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