Re: Unsmoothed car battery charger - is it crap?

An unpolarised battery isn't much use.

It's a sealed battery. Are they better or worse than electrolyte batteries when the charge drops to very low?

Similar, the difference is when they're overcharged , but any battery with a high CCA compared to it's capacity won't like being hard discharged. Boost it for a few hours on the old charger, charge it up on a decent one or by driving the car & see if it's still happy.

Dunno - might make a good door stop

Fair point.

In message , geoff writes

Depends a bit on size.

Last week a VERY large hornet decided to take a stroll across my work bench. A 2.8Ah Yuasa flattened it perfectly. Although I must admit that it was not unpolarised, the battery that is.

Any one have any other uses for old batteries?

An AC battery would be darn handy...

Adam

You've not met Radioheads big battery have you :-)

"Duncan Wood" wrote in news:op.uu58ttjshaghkf@lucy:

it may not be truly "sealed",the cell caps may be under a sticker or 3 cells having one big "cap". HOWEVER,for an old battery,the plates are likely sulfated and not capable of accepting a charge;the sulfate acts as an insulator.

auto lead-acid batteries typically only last 4-5 years,depending on the climate;hotter climates shorten the life.

A large percentage of sulphated batteries can be recovered to initial (pre-sulphation) glory - but it takes time and patience along with a reasonable technique.

Although they're called sealed, car batteries are actually low maintenance types which are still wet. Some serious off roaders may use SLA - but don't know of any car which does.

MX5s IIRC

Yes, when religion peddlers come to the door, they make great things to throw.

"But, I didn't see that guy standing there, sorry!"

BTW, don't unpolarized batteries just provide AC? And if that's the case, how do you specifiy 50 or 60 Hz?

Yes. 0VAC

Of course, in Spice they can deliver whatever voltage/frequency you want. No need to worry about the little details of thermodynamics either.

...that is how fast it tumbles when thrown?

In message , PeterD writes

The further you drop it, the more it hurts ...

Optima sells SLA batteries intended for vehicles. I don't know of any car manufacture that uses one as the OEM battery, but I've seen plenty of them in cars. Whether they have any real advantage over conventional low maintenance automotive batteries in that application, I don't know.

I don't think Optima is SLA - ie gel electrolytic. It's wet but spill proof.

Love all the blurb about how long they last. If only they backed that up with a warranty.