On 18/10/2020 15:58, Jethro_uk wrote:
On Sun, 18 Oct 2020 15:48:37 +0100, williamwright wrote:

On 18/10/2020 11:00, Dave Liquorice wrote:
That's another partial solution but unless regulary tested the
batteries get cooked by being on constant "trickle charge".

This is an oft-repeated fallacy. A half decent intelligent charger won't
do this. I have just tested an 8Ah lead-acid that's been on charge since
August 2014 with breaks and discharge only when we've had power cuts,
and it's fine. Comes out at 5Ah when discharged at 250mA which I think
is good enough.

Over the years I've spent a fortune on so called intelligent chargers.
All I have to show for it is a pile of failed rechargeables

I think they're better with larger lead-acid than small batteries.


Obviously cheap chargers are a different kettle of fish entirely. I
recently encountered a wall-wart style thing that had unconditional
no-load voltage of 16.3V. It had killed a 12V lead-acid.

How about UPS ? I gave up after having to buy a 3rd SLA battery for my
UPS in 6 years. Never once actually used when the power failed, just sat
there slowly ballooning.

I used to use UPSes to reduce problems with banks of sky boxes at
'critical' head ends (those serving systems where the reaction of the
residents to a failure of sky reception might be to murder each other).
The UPSes were fairly up market, (cost being no object in view of the
murdering each other issue) and I didn't have much trouble with battery
failures. That could be because the UPSes tended to be replaced every
few years anyway.

Bill