How to stop sealed lead acid battery sulfasion

[John Phoenix]

I am buying an electronic bike kit online. This is a kit with a battery operated motor for my mountain bike that lets me travel 25 miles an hour with a range up to 20 miles. It uses a battery pack of 3, 12 volt batteries (bike needs 36V) at 12AH. I wanted this to go to my fishing hole and fish, then a few hours later return home. I even called the company to be sure the kit could do the job with all my fishing gear before I ordered. The guy I spoke to did not tell me about battery sulfasion.

 

A fellow on an e-bike forum told me I would not be able to use the bike in this manner because if I let the bike sit any length of time before putting it on the charger it would become damaged due to sulfasion.

 

I was crestfallen. However someone suggested that as long there is a flow of current the sulfasion will not occur. It should not matter if the current is outgoing or incoming they said.

 

Is this true?

 

If this is true, they suggested I may be able to solve the problem by hooking up a small solar panel to the battery to give it just enough of a charge to prevent sulfasion.

 

What do you guys think of this? Would it work?

 

If so - How do I figure the correct size of such a solar charger that would work?

 

If this will not work.. are there any other options? I cannot afford the more expensive better batteries such as LiPO4 batteries. They are very expensive and I am barely affording this e-bike kit as it is, so i am looking for a very cheap solution to my problem.

Edited October 12, 2010 by John Phoenix

[John Phoenix]

20 people saw this and no one has a clue? Please help.

[CaptainPanic]

What is sulfasion?

 

I've never heard of it. I must admit that I was never very good at electrochemistry, but generally speaking I at least recognize keywords that I saw before.

 

If I understand you correctly, then you plan to use the old fashioned lead acid battery, also used in cars? But cars are able to stop without their batteries going flat.

[Mr Skeptic]

Cars recharge their batteries immediately upon starting. He's talking about an electric motorbike.

 

Honestly, I don't really know the answer to your question. I'd have to look it up myself.

[CaptainPanic]

Apparently sulfasion is a process that damages batteries when they are not used.

 

But the whole idea of a battery is that you can store energy and use it later... so I am still a bit lost.

[John Phoenix]

Well I must say I am shocked none of your guys are up on this subject.. being that it's all about chemistry. I already have a good explanation of why sulfasion occurs from an ebike website. I did find a product that claims to stop the process by adding a small solar charger - found here called the Solargizer http://www.survivalunlimited.com/batteries/solargizer36vLugAC.htm

 

I wanted some hard core scientists to tell me how sound this idea is. If good, i need to re-create this device with used parts if possible to fit my budget.

[rogerxd45]

well the solar 12v chargers are a lot cheaper that they make for cars, check out harbor freight.

 

since your using 3 12v batteries there should be a way to set it up so it charges each battery individually and thus only requiring a 12v panel

[Dune]

Apparently sulfasion is a process that damages batteries when they are not used.

 

But the whole idea of a battery is that you can store energy and use it later... so I am still a bit lost.

 

The damage is caused during periods of discharge...beyond a certain point, say 80%. A trickle charge from solar panel would address this, as would a deep-cycle lead acid battery, designed to be deeply discharged during use. The bike salesman should have informed you of this.

 

Another option would be to use the petals some, and or not cruise at full speed, thereby keeping the bank's voltage above 80% of full charge. You could keep track of the battery voltage with a very inexpensive voltmeter, mounted on your handlebars.

 

As to which solar panel, the smallest, lightest one possible. Additonaly, inquire of the bike kit's manufacturer about regenerative braking, which would also help with your problem.

[insane_alien]

i would assume that the bikes batteries are deep cycle batteries as only a moron would put starter batteries in such a design.

 

anyway, sulfation is the precipitation of lead sulphate within the battery and occurs when the batter is cole to being fully discharged as there is more lead sulphate around.

 

there isn't really any way to combat this as its an intrinsic property of a lead acid battery.

 

next time you buy a kit, go for a lithium battery as they perform better over deep cycle discharges.

 

really its just that lead acid batteries are pretty poor. cheap to make but not that great.

[John Cuthber]

"I wanted some hard core scientists to tell me how sound this idea is. "

Then learn to spell.

[Dune]

I would asume that they are not deep-cycle, or it wouldn't be a big issue.

[insane_alien]

oh deep cycle batteries still experience precipitation of lead sulphate. they don't stop that.

 

what is different about deep cycle batteries is that the lead plates are thicker and sturdier. if you deep cycle a car battery you run the risk of degrading the plates to the point where they break up and the broken offareas are no longer functional as an electrode.

 

a deep cycle battery will never get to the point where it breaks up.

 

sulfation on the other hand is just due to the insoluble nature of lead sulphate which is present in exactly the same concentrations in both batteries.

[Dune]

 

 

what is different about deep cycle batteries is that the lead plates are thicker and sturdier. if you deep cycle a car battery you run the risk of degrading the plates to the point where they break up and the broken offareas are no longer functional as an electrode.

 

a deep cycle battery will never get to the point where it breaks up.

 

 

Exactly. Thats why it wouldn't be an issue.

 

 

sulfation is the precipitation of lead sulphate within the battery and occurs when the batter is cole to being fully discharged as there is more lead sulphate around.

 

there isn't really any way to combat this as its an intrinsic property of a lead acid battery.

 

 

 

Sulfation increases as voltage declines.

Any action which icreases voltage reduces sulfation

[insane_alien]

Exactly. Thats why it wouldn't be an issue.

 

what does plate thickness have to do with solubility of lead sulphate?

Edited November 14, 2010 by insane_alien

[Genecks]

I question whether or not the pedaling aspect could transfer energy to something, as mentioned in a previous post, which could then provide a steady current to the battery over time. Maybe pedaling would be more efficient than the solar panel. But I don't have enough engineering knowledge to suggest how to build such a pedaling apparatus.

 

Sounds like an issue where you are somewhat screwed. But if you live in consistently sunny conditions, a solar panel might not be a bad idea.