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I've discovered a bit about Lead Acid (LA) batteries over the years and thought someone may find some use.
It's maybe a little loose, eh
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LA batteries can give the impression that they are good, and then one day they no longer work. But the reality is more like when they are new they deliver the most capacity that they are ever going to.
Meaning, they can both store and deliver the maximum amount of charge that they ever will in their life. From that point on, it is all downhill. Everyday, they have a little less store and deliver capacity.
What starts out as a 20 amp hour (Ah) battery becomes a 19 Ah battery, then 18, then 17 etc etc etc As the battery ages, it's capacity is de-rated.
The battery Ah rating on the battery is what the battery should be capable of delivering when it is new. Broadly, 20 Ah is thought of as delivering 20 amps for 1 hour. But like many things, the devil is in the detail. In the small print may be written “10 hour rating”
What they are saying is “the battery will not deliver 20amps for 1 hour, but it will deliver 2 amps for 10 hours”
The battery specification may also quote a temperature. Being a chemical device, the battery performance drops with the temperature of the battery.
If you think about the starting load on a battery, the biggest load must begin when the starter and engine are stationary. Accelerating the starter motor and engine from stationary is going to take the most power. And it is this acceleration where the performance of a new battery is most noticeable as the engine is positively belted into life.
The battery has sufficient delivery capability for the task plus some surplus. As the battery ages this spare capacity diminishes. But this is not noticeable. Once all that is gone, then the acceleration stage gets slower. Everyday, just a little bit so it is not easily noticed.
Until the weather changes, and one cold morning it is noticeable. At this point, the “performance drops with the temperature of the battery” combines with age related capacity de-rating. If you do not want untimely battery failure, now is a good time to get a new one.
Then winter comes, one very cold morning. Hit the starter and nothing. “Ohh, my battery just died” Actually, no. Your battery has been dying a long slow death from the day you bought it.
To the best of my knowledge age related death occurs to all LA batteries, sealed lead acid (SLA), gel, or absorbed glass mat (AGM).
My interest in the batteries was not why this happens, but how to avoid cutting the life of the battery short.
And I learned:
If the battery voltage drops too low, and is left too low then the lead plates will gain a layer of sulfate. This is bad. Do not store a depleted battery, it must be kept charged. The unloaded terminal voltage should read about 12.6 to 12.65 volts. That's not on a charger, unattached.
In another (work) department the guys where maintaining a veritable fleet of SLA's that where deployed for about 2 weeks every year. Over the years a lot of effort went into careful maintenance of the batteries with them being routinely monitored and charged. This did not help, they found that they needed to buy a new fleet of batteries every year.
After a bit of research we decided to put them in a fridge and keep at fridge (3 - 5 C) temp. This did work, the batteries lasted more than one year. How long I never got to ask, but out of everything we tried, this was the best. And there was no maintenance required. The batteries came out (of the fridge) with an acceptable terminal voltage.
Google “lead acid battery life and temperature” for riveting reading on the subject.
Relating to a bike:
My bike uses a bit of battery power doing nothing, just sitting there. Seems to fluctuate, I think an average of about 8mA (0.008 amps) would be close.
I would not want to consume more than about 1 Ah of capacity out of my battery without replenishing it, so this means I would need to charge the battery about every 5 days if the bike is not being ridden in this time.
Storage:
For summer storage I take the battery out and put it in the fridge.
If I lived in a cold location I would leave the battery in the bike but disconnect it so there is no drain.
So long as I could do that without the acid freezing. The freezing temperature of the battery acid is an interesting topic to google. Here is a good read.
What I use:
The last battery I bought was the cheapest one I could find on the internet. $60 posted to me. It is a SLA. So a fully flooded standard battery. It was sent dry, I put the acid in out of little bottles then charged it.
I went this route as I am thinking where I live I can only get 3 years out of a battery. Because of the heat. So far so good, at time of writing it is 8 months old.
I like the idea of fully flooded, the liquid acid would have more consistent contact with the plates than gel, it seems to me. That is all, no expertise claimed here.
The AGM batteries are required for ocean racing sail boats. This is because if things really don't go well and you end up upside down, you are not floating around inside your boat with the battery's acid mixed in with the water. Even punctured, the AGM battery will contain most of it's irritants.
AGM batteries should also be mechanically strong and have superior tolerance for shock and vibration. Good choice for enduro bikes and rockets I would think.
For my strom I don't really need that. The battery is quite well protected. I suspect if it gets smashed the leaking acid will not really matter to me.
The end, hope you found some interest. CH
It's maybe a little loose, eh
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
LA batteries can give the impression that they are good, and then one day they no longer work. But the reality is more like when they are new they deliver the most capacity that they are ever going to.
Meaning, they can both store and deliver the maximum amount of charge that they ever will in their life. From that point on, it is all downhill. Everyday, they have a little less store and deliver capacity.
What starts out as a 20 amp hour (Ah) battery becomes a 19 Ah battery, then 18, then 17 etc etc etc As the battery ages, it's capacity is de-rated.
The battery Ah rating on the battery is what the battery should be capable of delivering when it is new. Broadly, 20 Ah is thought of as delivering 20 amps for 1 hour. But like many things, the devil is in the detail. In the small print may be written “10 hour rating”
What they are saying is “the battery will not deliver 20amps for 1 hour, but it will deliver 2 amps for 10 hours”
The battery specification may also quote a temperature. Being a chemical device, the battery performance drops with the temperature of the battery.
If you think about the starting load on a battery, the biggest load must begin when the starter and engine are stationary. Accelerating the starter motor and engine from stationary is going to take the most power. And it is this acceleration where the performance of a new battery is most noticeable as the engine is positively belted into life.
The battery has sufficient delivery capability for the task plus some surplus. As the battery ages this spare capacity diminishes. But this is not noticeable. Once all that is gone, then the acceleration stage gets slower. Everyday, just a little bit so it is not easily noticed.
Until the weather changes, and one cold morning it is noticeable. At this point, the “performance drops with the temperature of the battery” combines with age related capacity de-rating. If you do not want untimely battery failure, now is a good time to get a new one.
Then winter comes, one very cold morning. Hit the starter and nothing. “Ohh, my battery just died” Actually, no. Your battery has been dying a long slow death from the day you bought it.
To the best of my knowledge age related death occurs to all LA batteries, sealed lead acid (SLA), gel, or absorbed glass mat (AGM).
My interest in the batteries was not why this happens, but how to avoid cutting the life of the battery short.
And I learned:
If the battery voltage drops too low, and is left too low then the lead plates will gain a layer of sulfate. This is bad. Do not store a depleted battery, it must be kept charged. The unloaded terminal voltage should read about 12.6 to 12.65 volts. That's not on a charger, unattached.
In another (work) department the guys where maintaining a veritable fleet of SLA's that where deployed for about 2 weeks every year. Over the years a lot of effort went into careful maintenance of the batteries with them being routinely monitored and charged. This did not help, they found that they needed to buy a new fleet of batteries every year.
After a bit of research we decided to put them in a fridge and keep at fridge (3 - 5 C) temp. This did work, the batteries lasted more than one year. How long I never got to ask, but out of everything we tried, this was the best. And there was no maintenance required. The batteries came out (of the fridge) with an acceptable terminal voltage.
Google “lead acid battery life and temperature” for riveting reading on the subject.
Relating to a bike:
My bike uses a bit of battery power doing nothing, just sitting there. Seems to fluctuate, I think an average of about 8mA (0.008 amps) would be close.
I would not want to consume more than about 1 Ah of capacity out of my battery without replenishing it, so this means I would need to charge the battery about every 5 days if the bike is not being ridden in this time.
Storage:
For summer storage I take the battery out and put it in the fridge.
If I lived in a cold location I would leave the battery in the bike but disconnect it so there is no drain.
So long as I could do that without the acid freezing. The freezing temperature of the battery acid is an interesting topic to google. Here is a good read.
What I use:
The last battery I bought was the cheapest one I could find on the internet. $60 posted to me. It is a SLA. So a fully flooded standard battery. It was sent dry, I put the acid in out of little bottles then charged it.
I went this route as I am thinking where I live I can only get 3 years out of a battery. Because of the heat. So far so good, at time of writing it is 8 months old.
I like the idea of fully flooded, the liquid acid would have more consistent contact with the plates than gel, it seems to me. That is all, no expertise claimed here.
The AGM batteries are required for ocean racing sail boats. This is because if things really don't go well and you end up upside down, you are not floating around inside your boat with the battery's acid mixed in with the water. Even punctured, the AGM battery will contain most of it's irritants.
AGM batteries should also be mechanically strong and have superior tolerance for shock and vibration. Good choice for enduro bikes and rockets I would think.
For my strom I don't really need that. The battery is quite well protected. I suspect if it gets smashed the leaking acid will not really matter to me.
The end, hope you found some interest. CH