SLA battery testing ?

[Bill Wright]

Not necessarily. I've seen people blunder on through a long career, despite their ignorance of the basic facts of their job. It's obvious that you have certain beliefs about batteries, some of which are right and some of which are wrong. You've picked up a few misapprehensions up over the years and they've solidified into gospel in your mind. A lot of people do that. So many low grade technicians proceed by a strange mixture of superstition, misapprehension, and trial and error.

Working for the NHS you wouldn't be worried about the lifespan of a little back-up battery. There wouldn't be any commercial pressure on you. If you abused such a battery by effectively shorting it out as you advocate you wouldn't care; you'd just toss it away and get the RS book out to order an over-priced replacement. You'd then imagine that you'd tested the battery, found it faulty, and done the right thing by replacing it. Thus another page would be added to your gospel of misapprehensions.

Bill

[Bill Wright]

Yes, but you missed my point. The spec is different for different discharge rates! If you look at the spec sheets from the better manufacturers you'll see different total capacities depending on the discharge rate, and the variation is quite large.

In real life, this means that a little 2 x 12Ah machine will seem to do better than you'd expect on flat hard floors (a day spent roaming round a shopping centre) and much worse than you'd expect outdoors in a hilly town with difficult surfaces.

To be pragmatic, if I was deciding whether or not to chuck a battery away I would want to know how well it's going to perform with the actual intended load. For a disability buggy this basically means how far will it go? So I'd get a real world indication of that by testing at a typical in-use discharge rate. For small buggies that's 3 to 8A.

Bill

[Bill Wright]

I don't know, but you aren't the only one to fall foul of the confusion about batteries for disability chariots. I started off with this game forty years ago when my mother got one, and I made mistakes with batteries and chargers. Since then I've looked after machines for the mother in law, my dad, and my wife, and I've also helped a few friends out.

It doesn't help that a lot of disability retailers are total rip-off merchants.

As well as two small machines (a 2 x12Ah and a 2 x 33Ah) we have a big beast that has two of the heaviest bigass batteries I've ever seem. They are 110Ah but they are far bigger and heavier than the 110Ah batteries I've used for the motorhome and for things at work. Since we get power cuts here I'm toying with the idea of rigging something up so I can power an inverter (or maybe only some lights) from the two big batteries!

If you have any issues with in-car chargers etc let me know. I've suffered with that as well!

Bill

[Dave Plowman (News)]

As long as they quote the discharge rate and you use that when checking it to spec, it is still a valid test.

[harryagain]

Full of crap as usual, these are test methods advocated by the manufacturers, often with equipment supplied by them.

RS don't supply such equipment.

More conjecture and drivel from a half wit. Things were alway done right beause it was cheaper in the long run and the business was going to be there for ever, not some fly by night nothing business. Often less mainteance and replacement costs too. There were no price cuts because of short term financial concerns. Things were always done to the highest standards because lives depended on it in some cases.

[harryagain]

Ah, so this where your vast experience of batteries has come from. Looking after a couple of "disability chariots".

Riiight.

[Bill Wright]

Precisely.

Bill

[Jethro_uk]

Sadly no reply from the latter following an enquiry on Tuesday. Guess they're not too desperate for custom them. I'll investigate the former supplier (who at least put prices and allow you to order through their website)

[Bill Wright]

Try looking for those Camden batteries on reseller websites.

Bill

[Dave Liquorice]

Game, set and match to Mr Wright.

"Viewing 1 - 20 of 189 products"

[Jethro_uk]

Already had the VPS link from you, so ordered from them. Arrived, charged, fitted, and SWMBO claims they are better than the last ones. Not quite sure how that works.

Regarding the camdenboss.com lack of interest. Their loss. Just seemed they took an awful lot of trouble to build a website just to ignore customers.