Lead acid batteries: Questions

[forexer]

I'm one guy that loves these batteries but ironically i dont know much about them. I know they are extremely safe and durable. The only bad things about them is that they are damn heavy, takes a long time to charge, lower charge density and troubles when overly discharged. I'm talking about those maintenance free ones. I'm looking for 12V ones or even 6V ones. Planning to get those with at least 70WH.

Questions: Why do they take so long to charge?

How can i charge them? What chargers do i use? What happens if i over amp them?

Do you like them?


Thanks and regards,:twothumbs

Forexer

 

[fivemega]

I'm one guy that loves these batteries but ironically i dont know much about them. I know they are extremely safe and durable. The only bad things about them is that they are damn heavy, takes a long time to charge, lower charge density and troubles when overly discharged. I'm talking about those maintenance free ones. I'm looking for 12V ones or even 6V ones. Planning to get those with at least 70WH.

Questions: Why do they take so long to charge?

How can i charge them? What chargers do i use? What happens if i over amp them?

Do you like them?


Thanks and regards,:twothumbs

Forexer

They are heavy, low energy density and must be fully recharge when not in use. Another word, you better recharge after usage and top off once a while.
You can charge them quickly with proper high current charger.
Each battery chemistry has it's own place of usage and lead acid is still good for vehicles and industrial use where space and weight is not very important.
Normally they are low price compare to similar capacity of other type battery and they performe well under heavy load.

 

[mattheww50]

Generally lead acid cells fall into two categories. They can be designed to tolerate deep discharge very well, or they tolerate overcharging very well. Generally if they do one well, they are pretty intolerant of the other. I.E. those designed for deep cycle use don't tolerate overcharging very well, and those that tolerate overcharging very well (automotive), don't tolerate being deep discharged very well.

Lead acid cells are best charged with a constant voltage charger that is temperature compensated, and if properly vented, most can actually be charged at high rates (~C).
However low rate chargers are widely available, and low cost, typically an automotive type storage battery will tolerate charging at about 2 amps almost indefinitely. So long term charge rates in the C/40 to C/80 range are generally regarded as safe.

Overcharging does result in the electrolysis of water, so most automotive batteries are designed for to be able to add water to the cells to replace that which is lost. It takes a lot of overcharging to remove significant amounts of water (check out how many amp seconds it takes to move 1 Mole of electrons). It also tends to slowly convert the lead plates to lead sulfate, reducing storge capacity.

As others have pointed out, these cells aren't the greatest in terms of energy density, they are quite robust relative to most rechargeable cells however, and will tolerate very high discharge rates.

They are. are relative inexpensive for the capacity they provide. Just remember that the electrolyte is sulfuric acid, so handle with care and dispose of properly.

 

[TranceAddict]

1. go for AGM battery
2. use Xantrex 3 stage battery charger

best combination, hassle free.

 

[photonwave]

I use deep-cycle marine batteries and a trace charge controller that stops charging past 12.8v, but that's for solar charging. Any typical 2 or 3 stage charger should suit your needs.

You run too much charging current or voltage, you're likely to burn out the interconnects between the lead cells, thereby degrading capacity, or killing the battery outright.

 

[forexer]

Thanks guys, i'll ask if i have further quires

Forexer

 

[65535]

They're pretty safe, but if shorted to have potential to explode soaking the surroundings in sulfuric acid. They are great for clean DC power though.

 

[photonwave]

They're pretty safe, but if shorted to have potential to explode soaking the surroundings in sulfuric acid. They are great for clean DC power though.

Nice username, Mr. Ports I shall dub thee in the back of my mind.

I've made a few SLAs explode. Right now I'm watching the developments in Nickel-Zinc batteries, as they've significantly improved the charge-cycle count and the 1.6v is certainly handy, especially for devices that "require Alkaline." The only thing I'm waiting for is equivalent mAh to Ni-Mh and that's the end of Ni-Cd and Ni-Mh industry for the most part, except for special applications.