Re: APC Batteries.

["domdevitto" <dom@xxxxxxxxxxx>]

> --- In ukha_d@xxxxxxx, "domdevitto" <dom@> wrote:
> > Nope,
> > I use a car charger to bring the batts to 100%, connected them to
> the
> > UPS and immediately after the first full 'to switchoff' use,
> neither
> > the UPS, nor a car charger could bring the batts back to life :-(
>
> I would think the batteries had failed for other reasons.
> I've had a car parked up where the battery was really flat - far
> more than a UPS would let a battery go to.  Yet that charged up ok.
> Sometimes using a regulated bench PSU is better than a car charger
> or UPS.  Though you need to know what you're doing.

Yeah - seemed very odd to me too :-( Maybe I'll gentle trickle them
with a bench PSU, but I think I'll just keep with my 3000va unless
some storms hit.

[snip]
> The problem here is the 700 doesn't have a fan so the heat would
> build up and up.  Bigger UPSs with fans should cope with longer
> runtimes.
[snip]
>
> An APC Smart 3000 and Smart 700 use basically the same components.
> The 3000 has more FETs to carry the load of course.

and a fan :-)

> > I believe, from the last time I was at a datacentre (yesterday!),
> that
> > 'proper' UPS tend to use lead-acid (same as car batteries) purely
> for
> > price, but I guess the circuitry switches off well before they
are
> > deep cycled [the generator should be up after a minute or so].
> This
> > makes sense, as gel-cells are more than twice the price, and
space
> > isn't a problem for building-wide UPS.
>
> I wouldn't think they use wet acid (car) batteries indoors.  They
> can vent hydrogen gas (not good in a closed room).  And if knocked
> over can spill acid.  UPS batteries aren't the Gel type, they are AGM.
> Andy

Yeah, though AC is critical in our environments - so hydrogen won't
ever build up.  I'll check the batts in the mockup lab when I get back
to work - but I'm pretty sure they were 'cheap and cheerful'
lead-acids. Once saw 4 pallets (stacked maybe 6-8 high) outside a main
datacentre, so I know our policy is "quantity over quality" :-)

Thanks for the bench tip Andy - I read *lots* above this before
modding my APC, so I know that a bench can do the job (and is cheaper,
if pennies matter), but you need to be careful, as you say.

Dom