I have been asked to attach a small solar charger panel for trickle
charger (maybe 6 inch square) thingy to a garage roof which has concrete
type (not slate) roof tiles.
I wont see the job until Saturday so cant be 100% sure about anything.
Whats the best way to attach it, I first thought silicone but I doubt
that would adhere to the tiles, Then I am thinking just slip the bracket
(presumably it has one) under a tile.

Any other thoughts? Could I drill into the tiles and use a small screw?

On 10/06/2014 16:44, ss wrote:
I have been asked to attach a small solar charger panel for trickle
charger (maybe 6 inch square) thingy to a garage roof which has concrete
type (not slate) roof tiles.
I wont see the job until Saturday so cant be 100% sure about anything.
Whats the best way to attach it, I first thought silicone but I doubt
that would adhere to the tiles, Then I am thinking just slip the bracket
(presumably it has one) under a tile.

Any other thoughts? Could I drill into the tiles and use a small screw?

A high tack PU glue will do it, but for the size of toy PV panel you are
talking about it probably isn't even worth the effort of trying.

A 3'x1' PV panel at least stands a chance of being worthwhile.

--
Regards,
Martin Brown

ss wrote:
I have been asked to attach a small solar charger panel for trickle
charger (maybe 6 inch square) thingy to a garage roof which has concrete
type (not slate) roof tiles.
I wont see the job until Saturday so cant be 100% sure about anything.
Whats the best way to attach it, I first thought silicone but I doubt
that would adhere to the tiles, Then I am thinking just slip the bracket
(presumably it has one) under a tile.

Any other thoughts? Could I drill into the tiles and use a small screw?
Stainless steel " meccano" strip bent into a asymmetric U shape. feed
the ends above and below a particular tile and attach the ends to the
battens from the inside making small slots in the felt if fitted.

I got my strips from Navitron and used them to fit a solar thermal array
last year http://www.navitron.org.uk/product_d...D=62&catID=121

On 10/06/2014 17:05, Bob Minchin wrote:
ss wrote:
I have been asked to attach a small solar charger panel for trickle
charger (maybe 6 inch square) thingy to a garage roof which has concrete
type (not slate) roof tiles.
I wont see the job until Saturday so cant be 100% sure about anything.
Whats the best way to attach it, I first thought silicone but I doubt
that would adhere to the tiles, Then I am thinking just slip the bracket
(presumably it has one) under a tile.

Any other thoughts? Could I drill into the tiles and use a small screw?
Stainless steel " meccano" strip bent into a asymmetric U shape. feed
the ends above and below a particular tile and attach the ends to the
battens from the inside making small slots in the felt if fitted.

I got my strips from Navitron and used them to fit a solar thermal array
last year http://www.navitron.org.uk/product_d...D=62&catID=121

They look very flimsy, has the panel been through a storm yet?

On Tue, 10 Jun 2014 16:44:35 +0100, ss wrote:

I have been asked to attach a small solar charger panel for trickle
charger (maybe 6 inch square) thingy

Hum, I bought one with idea of it keeping the battery topped up on
the standby genset. Was connected for maybe 6 months, when I came to
use or maybe routine test the genset the battry was flat. After use I
left the panel disconected, similar time interval, battery fine...

OK to be fair the panel is in a NW facing window but it's little
light flashes... I guess the leakage through it when dark is not
being made up by the small amount of lecky generated during the day.

Silicone will stick it or one of the building adhesives, but will
leave silicone behind when it's removed. Stainless strip or even a
decently galvanized bit if steel withe the panal attached and pushed
up under a tile and hooked onto the batten will hold something that
small.

--
Cheers
Dave.

On 10/06/2014 20:02, Dave Liquorice wrote:
On Tue, 10 Jun 2014 16:44:35 +0100, ss wrote:

I have been asked to attach a small solar charger panel for trickle
charger (maybe 6 inch square) thingy

Hum, I bought one with idea of it keeping the battery topped up on
the standby genset. Was connected for maybe 6 months, when I came to
use or maybe routine test the genset the battry was flat. After use I
left the panel disconected, similar time interval, battery fine...

Crap consumer ones from the likes of Maplin need a Shotky diode in
series to prevent the battery charge leaking away through the low grade
solar panel silicon during the night. A 1N581x ought to do it.

OK to be fair the panel is in a NW facing window but it's little
light flashes... I guess the leakage through it when dark is not
being made up by the small amount of lecky generated during the day.

Yup and there really is no excuse for it the diode is a penny item.

Silicone will stick it or one of the building adhesives, but will
leave silicone behind when it's removed. Stainless strip or even a
decently galvanized bit if steel withe the panal attached and pushed
up under a tile and hooked onto the batten will hold something that
small.

Something that small will also be entirely useless.

--
Regards,
Martin Brown

Yes i was just wondering about such a puny panel. That sounds like the sort
of cheap rubbish they used to sell with those plant turners for window
sills.
Brian

--
From the Sofa of Brian Gaff Reply address is active
"Martin Brown" wrote in message
...
On 10/06/2014 16:44, ss wrote:
I have been asked to attach a small solar charger panel for trickle
charger (maybe 6 inch square) thingy to a garage roof which has concrete
type (not slate) roof tiles.
I wont see the job until Saturday so cant be 100% sure about anything.
Whats the best way to attach it, I first thought silicone but I doubt
that would adhere to the tiles, Then I am thinking just slip the bracket
(presumably it has one) under a tile.

Any other thoughts? Could I drill into the tiles and use a small screw?

A high tack PU glue will do it, but for the size of toy PV panel you are
talking about it probably isn't even worth the effort of trying.

A 3'x1' PV panel at least stands a chance of being worthwhile.

--
Regards,
Martin Brown

ss wrote:
I have been asked to attach a small solar charger panel for trickle
charger (maybe 6 inch square) thingy to a garage roof which has concrete
type (not slate) roof tiles.

Does the building not have a mains supply?

Bill

On 10/06/2014 23:22, Bill Wright wrote:
ss wrote:
I have been asked to attach a small solar charger panel for trickle
charger (maybe 6 inch square) thingy to a garage roof which has
concrete type (not slate) roof tiles.

Does the building not have a mains supply?

Bill

From what I can gather the garage is 50 yards from the house and no
elec supply.

On 10/06/2014 22:29, Brian Gaff wrote:

Yes i was just wondering about such a puny panel. That sounds like the sort
of cheap rubbish they used to sell with those plant turners for window
sills.
Brian

The cost of the tube of glue will probably be greater than the total
lifetime output of electricity of such a small panel. Quite a lot of the
ones on garden lamps go bad after less than two years.

And without a series diode the low grade silicon of a cheap PV will
probably ruin the battery it is supposed to be trickle charging.

--
Regards,
Martin Brown

On Tue, 10 Jun 2014 22:29:30 +0100, Brian Gaff wrote:

Yes i was just wondering about such a puny panel. That sounds like the
sort of cheap rubbish they used to sell with those plant turners for
window sills.

It doesn't take much to keep a lead acid battery topped up. An
average of just a mA or two will do it. As I found out, the problem
with a PV panel is the leakage when dark, that can be greater than
the gain when lit.

--
Cheers
Dave.

On 11/06/2014 00:28, ss wrote:
On 10/06/2014 23:22, Bill Wright wrote:
ss wrote:
I have been asked to attach a small solar charger panel for trickle
charger (maybe 6 inch square) thingy to a garage roof which has
concrete type (not slate) roof tiles.

Does the building not have a mains supply?

Bill

From what I can gather the garage is 50 yards from the house and no
elec supply.

In that case carrying a 17Ah lead acid battery down there every now and
then is probably a much more cost effective solution to whatever problem
you are supposed to be trying to solve.

--
Regards,
Martin Brown

In article ,
"Brian Gaff" writes:
Yes i was just wondering about such a puny panel. That sounds like the sort
of cheap rubbish they used to sell with those plant turners for window
sills.

I bought one from Maplin some years ago. It generated enough output to
light up the LED on it, but no more. It was sold as a 12V car battery
charger. It might have been useful to counteract self-discharge of a
stored battery, but no more.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Wed, 11 Jun 2014 07:42:20 +0000 (UTC), Andrew Gabriel wrote:

I bought one from Maplin some years ago. It generated enough output to
light up the LED on it, but no more. It was sold as a 12V car battery
charger.

Probably the same as the one I have, 5" wide 14" ish long?

It might have been useful to counteract self-discharge of a stored
battery, but no more.

In full sun it probably will charge a bit but really all they are is
self discharge eliminators. The LED on mine flashes, when it's on
there is very little on the output, the mark/space is around 1:1 so
50% of the very little produced is wasted... I must rescue it from
the garage and "get at it". B-)

--
Cheers
Dave.

In article ,
ss wrote:
I have been asked to attach a small solar charger panel for trickle
charger (maybe 6 inch square) thingy to a garage roof which has concrete
type (not slate) roof tiles.
I wont see the job until Saturday so cant be 100% sure about anything.
Whats the best way to attach it, I first thought silicone but I doubt
that would adhere to the tiles, Then I am thinking just slip the bracket
(presumably it has one) under a tile.

Any other thoughts? Could I drill into the tiles and use a small screw?

I'd not disturb the roof in any way. If it leaks at a later date for
whatever reason you'll get the blame. Just glue it in place.

--
*Kill one man and you're a murderer, kill a million and you're a conqueror.

Dave Plowman London SW
To e-mail, change noise into sound.

On 11/06/2014 11:03, Dave Plowman (News) wrote:
In ,
wrote:
I have been asked to attach a small solar charger panel for trickle
charger (maybe 6 inch square) thingy to a garage roof which has concrete
type (not slate) roof tiles.
I wont see the job until Saturday so cant be 100% sure about anything.
Whats the best way to attach it, I first thought silicone but I doubt
that would adhere to the tiles, Then I am thinking just slip the bracket
(presumably it has one) under a tile.

Any other thoughts? Could I drill into the tiles and use a small screw?

I'd not disturb the roof in any way. If it leaks at a later date for
whatever reason you'll get the blame. Just glue it in place.


Thanks for the replies all. Yes it probably is a crappy charger but he
already has bought it but cant work out how to fix it. I will get out
there and probably find he has a window in the garage and he can just
sit it on the window sill :-) He has a 1st class honours degree in
mathematical physics but can hardly use a flippin screwdriver.

In article ,
ss wrote:
He has a 1st class honours degree in
mathematical physics but can hardly use a flippin screwdriver.

And doesn't know much about solar panels. The quoted output of this sort
is usually a peak one. The average often close to zero. Maybe even a
negative in practice.

--
*Why does the sun lighten our hair, but darken our skin?

Dave Plowman London SW
To e-mail, change noise into sound.

dennis@home wrote:
On 10/06/2014 17:05, Bob Minchin wrote:
ss wrote:
I have been asked to attach a small solar charger panel for trickle
charger (maybe 6 inch square) thingy to a garage roof which has concrete
type (not slate) roof tiles.
I wont see the job until Saturday so cant be 100% sure about anything.
Whats the best way to attach it, I first thought silicone but I doubt
that would adhere to the tiles, Then I am thinking just slip the bracket
(presumably it has one) under a tile.

Any other thoughts? Could I drill into the tiles and use a small screw?
Stainless steel " meccano" strip bent into a asymmetric U shape. feed
the ends above and below a particular tile and attach the ends to the
battens from the inside making small slots in the felt if fitted.

I got my strips from Navitron and used them to fit a solar thermal array
last year
http://www.navitron.org.uk/product_d...D=62&catID=121

They look very flimsy, has the panel been through a storm yet?

I used 9 of them - and had no problems. we live opposite a open space at
the top of a hill and the wind rattles the concrete tiles regularly in
the winter and the panel (30 tubes) about 2.4 sq m has stayed put.

Maybe you are thinking of the PV panel type mountings which are
considerably thicker and made from aluminium?

ss wrote:
I have been asked to attach a small solar charger panel for trickle
charger (maybe 6 inch square) thingy to a garage roof which has
concrete type (not slate) roof tiles.
I wont see the job until Saturday so cant be 100% sure about anything.
Whats the best way to attach it, I first thought silicone but I doubt
that would adhere to the tiles, Then I am thinking just slip the
bracket (presumably it has one) under a tile.

Any other thoughts? Could I drill into the tiles and use a small
screw?

A solar panel that small is pretty much useless - it would charge one 600mah
AA battery on a very sunny day, and on a cloudy day it wouldn't even do
that.
Those garden solar lights have a 2 X 2 inch panel and one rechargeable
600mah AA battery and usully one small LED bulb and they don't even stay lit
all night

On 11/06/2014 18:34, Bob Minchin wrote:

I got my strips from Navitron and used them to fit a solar thermal array
last year
http://www.navitron.org.uk/product_d...D=62&catID=121

They look very flimsy, has the panel been through a storm yet?

I used 9 of them - and had no problems. we live opposite a open space at
the top of a hill and the wind rattles the concrete tiles regularly in
the winter and the panel (30 tubes) about 2.4 sq m has stayed put.

Maybe you are thinking of the PV panel type mountings which are
considerably thicker and made from aluminium?

No, I'm thinking of the ~6 mm thick 30mm x 70mm aluminium sections
holding my thermal panel.

It is adjustable for angle but I thought it was OTT.

dennis@home wrote:
On 11/06/2014 18:34, Bob Minchin wrote:

I got my strips from Navitron and used them to fit a solar thermal
array
last year
http://www.navitron.org.uk/product_d...D=62&catID=121

They look very flimsy, has the panel been through a storm yet?

I used 9 of them - and had no problems. we live opposite a open space at
the top of a hill and the wind rattles the concrete tiles regularly in
the winter and the panel (30 tubes) about 2.4 sq m has stayed put.

Maybe you are thinking of the PV panel type mountings which are
considerably thicker and made from aluminium?

No, I'm thinking of the ~6 mm thick 30mm x 70mm aluminium sections
holding my thermal panel.

It is adjustable for angle but I thought it was OTT.

Those sound much more like the sections on my PV array.
The Thermal panel is much lighter. The heat exchanger is a single 35mm
copper pipe with a litre or so of gycol mix plus 30 vacuum tubes. I
think the total weight is around 100kg.

If yours is a flat plate panel and has the ability to be angled off the
roof, it might need the strength in the wind?

On 11/06/2014 22:14, Bob Minchin wrote:
dennis@home wrote:
On 11/06/2014 18:34, Bob Minchin wrote:

I got my strips from Navitron and used them to fit a solar thermal
array
last year
http://www.navitron.org.uk/product_d...D=62&catID=121

They look very flimsy, has the panel been through a storm yet?

I used 9 of them - and had no problems. we live opposite a open space at
the top of a hill and the wind rattles the concrete tiles regularly in
the winter and the panel (30 tubes) about 2.4 sq m has stayed put.

Maybe you are thinking of the PV panel type mountings which are
considerably thicker and made from aluminium?

No, I'm thinking of the ~6 mm thick 30mm x 70mm aluminium sections
holding my thermal panel.

It is adjustable for angle but I thought it was OTT.

Those sound much more like the sections on my PV array.
The Thermal panel is much lighter. The heat exchanger is a single 35mm
copper pipe with a litre or so of gycol mix plus 30 vacuum tubes. I
think the total weight is around 100kg.

If yours is a flat plate panel and has the ability to be angled off the
roof, it might need the strength in the wind?

Its a vacuum tube panel. Its much heavier than a solar PV panel.
PV panels weigh about 12 kg for a 250W one.
They are easily managed by one person, the thermal panel needs two.

On Wed, 11 Jun 2014 23:01:21 +0100, dennis@home wrote:

Its a vacuum tube panel. Its much heavier than a solar PV panel.
PV panels weigh about 12 kg for a 250W one.
They are easily managed by one person, the thermal panel needs two.

Er the manifold of vacuum tube panel is a bit of a lump but large
rather than heavy. A tube weighs not alot at all? Perhaps you don't
realise that the tubes plug into the manifold, you don't handle the
whole assembly as a single unit.

PV will need stronger fixings as the panels are solid and have a
higer windage than thermal tubes where the wind can pass betwen them.

--
Cheers
Dave.

On 11/06/2014 23:48, Dave Liquorice wrote:
On Wed, 11 Jun 2014 23:01:21 +0100, dennis@home wrote:

Its a vacuum tube panel. Its much heavier than a solar PV panel.
PV panels weigh about 12 kg for a 250W one.
They are easily managed by one person, the thermal panel needs two.

Er the manifold of vacuum tube panel is a bit of a lump but large
rather than heavy. A tube weighs not alot at all? Perhaps you don't
realise that the tubes plug into the manifold, you don't handle the
whole assembly as a single unit.

PV will need stronger fixings as the panels are solid and have a
higer windage than thermal tubes where the wind can pass betwen them.


There is no where for wind to pass through my panel, the multi-parabolic
reflector is pressed metal and the thing arrives pre-assembled.

On Thu, 12 Jun 2014 08:13:01 +0100, dennis@home wrote:

PV will need stronger fixings as the panels are solid and have a
higer windage than thermal tubes where the wind can pass betwen
them.

There is no where for wind to pass through my panel, the multi-parabolic
reflector is pressed metal and the thing arrives pre-assembled.

Not seen that type, have you a link for it?

--
Cheers
Dave.

On 12/06/2014 09:15, Dave Liquorice wrote:
On Thu, 12 Jun 2014 08:13:01 +0100, dennis@home wrote:

PV will need stronger fixings as the panels are solid and have a
higer windage than thermal tubes where the wind can pass betwen
them.

There is no where for wind to pass through my panel, the multi-parabolic
reflector is pressed metal and the thing arrives pre-assembled.

Not seen that type, have you a link for it?


http://www.vaillant.co.uk/products/r...erm-exclusive/

In article o.uk,
"Dave Liquorice" writes:
On Wed, 11 Jun 2014 07:42:20 +0000 (UTC), Andrew Gabriel wrote:

I bought one from Maplin some years ago. It generated enough output to
light up the LED on it, but no more. It was sold as a 12V car battery
charger.

Probably the same as the one I have, 5" wide 14" ish long?

Sounds like it.
As it was useless, I pulled it apart to look inside.
I don't seem to have it anymore, so I suspect I chucked out out.
I only bought it after they'd been significantly reduced, and didn't
expect much, but it failed to live up to even that.

It might have been useful to counteract self-discharge of a stored
battery, but no more.

In full sun it probably will charge a bit but really all they are is
self discharge eliminators. The LED on mine flashes, when it's on
there is very little on the output, the mark/space is around 1:1 so
50% of the very little produced is wasted...

Yep - exactly same with mine.

I must rescue it from
the garage and "get at it". B-)

ISTR the circuit was embedded in a lump of silicone, or some such.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Thu, 12 Jun 2014 23:49:52 +0000 (UTC), Andrew Gabriel wrote:

I must rescue it from the garage and "get at it". B-)

ISTR the circuit was embedded in a lump of silicone, or some such.

Wouldn't be surprised but just bunging in a schotty diode to stop the
leakage would be an improvement. I doubt it'll ever generate enough
umpf, even in direct sunlight, to damage a wet lead acid battery.

--
Cheers
Dave.

In article o.uk,
"Dave Liquorice" writes:
On Thu, 12 Jun 2014 23:49:52 +0000 (UTC), Andrew Gabriel wrote:

I must rescue it from the garage and "get at it". B-)

ISTR the circuit was embedded in a lump of silicone, or some such.

Wouldn't be surprised but just bunging in a schotty diode to stop the
leakage would be an improvement. I doubt it'll ever generate enough
umpf, even in direct sunlight, to damage a wet lead acid battery.

Don't know about current technology wet batteries, but charging them
really slowly use to cause the generation of large crystals on the
plates, which were much more prone to fall off (losing their storage
capacity), and build up a sediment at the bottom of the cell, where
they eventually short the plates out.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Fri, 13 Jun 2014 08:28:01 +0000 (UTC),
(Andrew Gabriel) wrote:

In article o.uk,
"Dave Liquorice" writes:
On Thu, 12 Jun 2014 23:49:52 +0000 (UTC), Andrew Gabriel wrote:

I must rescue it from the garage and "get at it". B-)

ISTR the circuit was embedded in a lump of silicone, or some such.

Wouldn't be surprised but just bunging in a schotty diode to stop the
leakage would be an improvement. I doubt it'll ever generate enough
umpf, even in direct sunlight, to damage a wet lead acid battery.

Don't know about current technology wet batteries, but charging them
really slowly use to cause the generation of large crystals on the
plates, which were much more prone to fall off (losing their storage
capacity), and build up a sediment at the bottom of the cell, where
they eventually short the plates out.

Which explanation rather neatly accounts for why a bank of 4 12v 36AH
car batteries used in place of the originally specified 17AH SLAs on
my SmartUPS 2000 only lasted 6 months or so at a time before they
started going 'leaky'!

Sadly, I did this 'experiment' _twice_ before realising the futility
of such an 'economic' solution' to the lack of the battery box that
normally would have come with my 'Bargain Purchase' at a radioham
rally a decade or so back.

The worst of this was this wasn't the first time I'd experienced this
problem a decade or so earlier. However, it was a 'one off' which I
put down to it being a defective battery I'd used with a 13.8v 4A CB
power pack to endow my PSU with low duty cycle high current output. A
common solution for the majority of the CBers running "100W Burners".

I've run out of suitable SLAs for the UPS and don't care too much for
the extortionate pricing of replacements so it's sat in the basement
in bypass. The "Protected Sockets" are no longer 'protected'.

However, I suppose I could use a very low output voltage mains
transformer to impose a 50Hz half volt peak to peak ripple on the
charging supply and try another set of 'cheap car batteries' but I
suspect I'd need something a little more sophisticated to maximise
battery life without confusing the UPS's original 'charging circuit'.

Luckily, I've downloaded several dozen APC UPS manuals and circuit
diagrams, including the all important SmartUPS 2000 one so I do have
some chance of being able to achieve this happy state of affairs.

The UPS manufacturers could have so easily addressed this issue but
it simply wasn't in their interest to do so (UPS supplied SLA
batteries are their equivilent to the inkjet printer manufacturer's
cash cow of inkjet refill cartridges).
--
J B Good

The UPS manufacturers could have so easily addressed this issue but
it simply wasn't in their interest to do so (UPS supplied SLA
batteries are their equivilent to the inkjet printer manufacturer's
cash cow of inkjet refill cartridges).

I've noticed on all the APC ones they seem to cook their SLA batteries
after a while ....
--
Tony Sayer

On Fri, 13 Jun 2014 16:40:22 +0100, tony sayer
wrote:



The UPS manufacturers could have so easily addressed this issue but
it simply wasn't in their interest to do so (UPS supplied SLA
batteries are their equivilent to the inkjet printer manufacturer's
cash cow of inkjet refill cartridges).

I've noticed on all the APC ones they seem to cook their SLA batteries
after a while ....

Well, after I posted that, I took a look at the charging circuit for
the 2000 and it seems incredibly complex for its function. The whole
circuit diagram for the UPS is spread over 6 sheets (the charger is
sheet6 BTW). In this case, the power comes from transformer terminals
1 and 2 on sheet 3 and following the trail takes you to the inverter
powerfet stack circuit (a full bridge cct attached to the very same
terminals that are used to feed the 5A rectifier diodes on sheet 6 -
the inverter transformer does double duty as a charging transformer).

I gave up pondering the problem any further and decided to google to
the wiki on Lead Acid battery technology with regard to best charging
regimes where it all became ever so complex over the issue of choosing
a charging voltage that's high enough to avoid sulphation yet low
enough to minimise corrosion.

Interestingly there are three different float charge volts per cell
figures for Gel, AGM and flooded cell types (2.23, 2.25 and 2.32 to
within a figure of +/- 0.05v[1] respectively) for 20 deg C temperature
with a temperature compensation figure of -.0235v per deg C rise per 6
cell battery).

Reading the article suggests it might not entirely be the UPS
designer's fault but more the terrible limitations of Lead Acid
battery technology (but that doesn't explain the 6 month life under
the benign management scheme of a UPS versus the 5 to 10 years life in
the harsher conditions of starter battery use).

I have considered the use of deep discharge flooded cell batteries
(there is a trimpot to adjust the float charging voltage) but that's
an even greater financial risk than buying a set of four cheap 36AH
SLI batteries (probably still cheaper per AH's worth of the APC
recommended SLA types though).

[1] The +/- 0.05v seems to make a mockery of the specific cell type
voltages and temperature compensation coefficient figures quoted which
leaves me wondering whether or not it is a per cell tolerance or, as
in the case of the temp comp figure, per 6 cell's worth.

You can see what I mean he
http://en.wikipedia.org/wiki/Lead-acid_battery
--
J B Good

On Fri, 13 Jun 2014 17:57:15 +0100, Johny B Good wrote:

I've noticed on all the APC ones they seem to cook their SLA
batteries
after a while ....

Aye, my small APC Smart UPS iNet 750 kills a set of SLA's in 3 to 4
years.

Interestingly there are three different float charge volts per cell
figures for Gel, AGM and flooded cell types (2.23, 2.25 and 2.32 to
within a figure of +/- 0.05v[1] respectively) for 20 deg C temperature
with a temperature compensation figure of -.0235v per deg C rise per 6
cell battery).

Recently been through this loop as well. In the case of my APC UPS
the killer seems to be the temperature. I reckon that the batteries
where normally at the upper 30's to 40 C, when you apply the derating
the voltage from the UPS is really rather high. Measured charge
voltage 27.7 V, calculated charge voltage at 40 C 26.58 V, 1.12 V to
high

I have considered the use of deep discharge flooded cell batteries
(there is a trimpot to adjust the float charging voltage)

No tweaky pot in my UPS. But digging about on the web found a mod to
add one and how to enter setup mode and adjust the settings so it
thinks the charge voltage is correct. I also removed the SNMP card
slot housing and fitted a PC expansion slot exhaust fan with thermal
speed control (using the MIC502 chip). Before the UPS used to run
decidedly warm to the touch, now it is cool.

Time will tell how much longer the batteries last (or not!).

--
Cheers
Dave.

In article ,
Johny B Good writes:
On Fri, 13 Jun 2014 16:40:22 +0100, tony sayer
wrote:



The UPS manufacturers could have so easily addressed this issue but
it simply wasn't in their interest to do so (UPS supplied SLA
batteries are their equivilent to the inkjet printer manufacturer's
cash cow of inkjet refill cartridges).

Their argument for high charge rate is that the UPS needs to be ready
for use again within a short time.

That isn't a valid excuse to carry on cooking the batteries once they
are charged, which is what used to happen in one we had at work.

We used to get 3 years viable life from an APC SmartUPS UPS, or 4
years life to completely dead.

OTOH, in another datacentre, we had a central 80kW UPS (Chloride
Gaedor?) with separate batteries which were 10+ years old and still
as good as new.

I've noticed on all the APC ones they seem to cook their SLA batteries
after a while ....

Well, after I posted that, I took a look at the charging circuit for
the 2000 and it seems incredibly complex for its function. The whole
circuit diagram for the UPS is spread over 6 sheets (the charger is
sheet6 BTW). In this case, the power comes from transformer terminals
1 and 2 on sheet 3 and following the trail takes you to the inverter
powerfet stack circuit (a full bridge cct attached to the very same
terminals that are used to feed the 5A rectifier diodes on sheet 6 -
the inverter transformer does double duty as a charging transformer).

I gave up pondering the problem any further and decided to google to
the wiki on Lead Acid battery technology with regard to best charging
regimes where it all became ever so complex over the issue of choosing
a charging voltage that's high enough to avoid sulphation yet low
enough to minimise corrosion.

Interestingly there are three different float charge volts per cell
figures for Gel, AGM and flooded cell types (2.23, 2.25 and 2.32 to
within a figure of +/- 0.05v[1] respectively) for 20 deg C temperature
with a temperature compensation figure of -.0235v per deg C rise per 6
cell battery).

Reading the article suggests it might not entirely be the UPS
designer's fault but more the terrible limitations of Lead Acid
battery technology (but that doesn't explain the 6 month life under
the benign management scheme of a UPS versus the 5 to 10 years life in
the harsher conditions of starter battery use).

Car batteries are not normally run down at all. Starting the engine
requires only a tiny proportion of their capacity, and they're
normally recharged from this within a minute or two even on tickover.
They are excellent at providing high current, but running them
flat kills them very quickly. Their capacity drops fairly linearly
over their life, but as you only need a tiny fraction of their capacity
to start the car, you normally won't notice until they are will under
10% left.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Fri, 13 Jun 2014 20:45:29 +0000 (UTC),
(Andrew Gabriel) wrote:

In article ,
Johny B Good writes:
On Fri, 13 Jun 2014 16:40:22 +0100, tony sayer
wrote:



The UPS manufacturers could have so easily addressed this issue but
it simply wasn't in their interest to do so (UPS supplied SLA
batteries are their equivilent to the inkjet printer manufacturer's
cash cow of inkjet refill cartridges).

Their argument for high charge rate is that the UPS needs to be ready
for use again within a short time.

That isn't a valid excuse to carry on cooking the batteries once they
are charged, which is what used to happen in one we had at work.

We used to get 3 years viable life from an APC SmartUPS UPS, or 4
years life to completely dead.

OTOH, in another datacentre, we had a central 80kW UPS (Chloride
Gaedor?) with separate batteries which were 10+ years old and still
as good as new.

I've noticed on all the APC ones they seem to cook their SLA batteries
after a while ....

Well, after I posted that, I took a look at the charging circuit for
the 2000 and it seems incredibly complex for its function. The whole
circuit diagram for the UPS is spread over 6 sheets (the charger is
sheet6 BTW). In this case, the power comes from transformer terminals
1 and 2 on sheet 3 and following the trail takes you to the inverter
powerfet stack circuit (a full bridge cct attached to the very same
terminals that are used to feed the 5A rectifier diodes on sheet 6 -
the inverter transformer does double duty as a charging transformer).

I gave up pondering the problem any further and decided to google to
the wiki on Lead Acid battery technology with regard to best charging
regimes where it all became ever so complex over the issue of choosing
a charging voltage that's high enough to avoid sulphation yet low
enough to minimise corrosion.

Interestingly there are three different float charge volts per cell
figures for Gel, AGM and flooded cell types (2.23, 2.25 and 2.32 to
within a figure of +/- 0.05v[1] respectively) for 20 deg C temperature
with a temperature compensation figure of -.0235v per deg C rise per 6
cell battery).

Reading the article suggests it might not entirely be the UPS
designer's fault but more the terrible limitations of Lead Acid
battery technology (but that doesn't explain the 6 month life under
the benign management scheme of a UPS versus the 5 to 10 years life in
the harsher conditions of starter battery use).

Car batteries are not normally run down at all. Starting the engine
requires only a tiny proportion of their capacity, and they're
normally recharged from this within a minute or two even on tickover.
They are excellent at providing high current, but running them
flat kills them very quickly. Their capacity drops fairly linearly
over their life, but as you only need a tiny fraction of their capacity
to start the car, you normally won't notice until they are will under
10% left.

I agree with that assessment but I think there was more to it than
just that. Despite the trickle charge tailing off to miliamps (when
new), this did eventually lead to high self discharge rates and cell
voltage imbalance which, in turn, led to higher trickle charging
current, accelerating the process of deterioration to the point where
the battery became a liability after a mere 6 months or so.

Considering the much higher float charge voltage used by alternators
(typically 14.0 to 14.2 volts) and the 150 odd amps discharge when
cranking the starter (and even higher current draw in wintertime
conditions), it's a rather surprising finding.

I've learnt the hard way (or, if you prefer, the easy way) that car
batteries aren't suited for such usage. Testing the batteries when new
to determine the endurance time to exhaustion 2 or 3 times in the
first week didn't suggest the relatively deep discharge was causing
any noticable loss of capacity.

The UPS would start charging the batteries within minutes of
completing each test which should have avoided the sulphation issue.
Admittedly, it needed a good 16 hours or more to complete the charging
process (normally a matter of 8 hours for the originally specified
17AH SLAs) but I don't think this was a material factor.

The normal advice over totally discharged Lead Acid batteries is to
not leave them longer than 24 hours in this state before putting them
back on charge. Perhaps I've misinterpreted this advice and it was
meant to say they should be fully recharged within 24 hours. Even on
the basis of this interpretation, the batteries were being fully
charged within this 24 hour period.

The problem seems to be exclusively down to the float charging
conditions since they'd deteriorate without being called upon to power
the inverter during a blackout.

One thing's for certain, I won't be entertaining the use of car
batteries as a substitute for SLA batteries. It's either SLA or Deep
discharge depending on how cheaply I can get my hands on a set of
four.
--
J B Good

On Fri, 13 Jun 2014 20:45:29 +0000 (UTC), Andrew Gabriel wrote:

Their argument for high charge rate is that the UPS needs to be ready
for use again within a short time.

Which is valid. If the thing switches off with flat batteries they
have to be suffciently recharged to enable any attached kit to shut
down gracefully should the power disappear again.

That isn't a valid excuse to carry on cooking the batteries once they
are charged, which is what used to happen in one we had at work.

Quite agree it's a poor design but common across APC UPS's. As some
one else said, replacement batteries to APC are like ink cartridges
to printer makers. Last set of batteries I bought (Mar 14) where
£29.99 delivered from Value Power Systems, their "own brand"
replacement pack, cheaper than 2 x Yusa NP batteries from them, the
pack used Yusa... APC wanted getting on for £50.00...
Car batteries are not normally run down at all. Starting the engine
requires only a tiny proportion of their capacity, and they're
normally recharged from this within a minute or two even on tickover.
They are excellent at providing high current, but running them
flat kills them very quickly.

Like once can be enough ... Thats why you can get deep discharge wet
lead acid batteries, sometimes termed caravan batteries.

--
Cheers
Dave.

On Sat, 14 Jun 2014 13:52:59 +0100 (BST), "Dave Liquorice"
wrote:

On Fri, 13 Jun 2014 20:45:29 +0000 (UTC), Andrew Gabriel wrote:

Their argument for high charge rate is that the UPS needs to be ready
for use again within a short time.

Which is valid. If the thing switches off with flat batteries they
have to be suffciently recharged to enable any attached kit to shut
down gracefully should the power disappear again.

That isn't a valid excuse to carry on cooking the batteries once they
are charged, which is what used to happen in one we had at work.

Quite agree it's a poor design but common across APC UPS's. As some
one else said, replacement batteries to APC are like ink cartridges

That was me! :-)

to printer makers. Last set of batteries I bought (Mar 14) where
£29.99 delivered from Value Power Systems, their "own brand"
replacement pack, cheaper than 2 x Yusa NP batteries from them, the
pack used Yusa... APC wanted getting on for £50.00...
Car batteries are not normally run down at all. Starting the engine
requires only a tiny proportion of their capacity, and they're
normally recharged from this within a minute or two even on tickover.
They are excellent at providing high current, but running them
flat kills them very quickly.

Like once can be enough ... Thats why you can get deep discharge wet
lead acid batteries, sometimes termed caravan batteries.

According to wikipedia, there are two varients of these Deep
Discharge batteries, the true deep dischrge type and the 'leisure'
ones to which you allude which are a compromise between high discharge
duty and deep discharge durability, i.e neither one thing or the other
although obviously a useful compromise for 'leisure' activities.
--
J B Good

On 13/06/2014 13:14, Johny B Good wrote:

I've run out of suitable SLAs for the UPS and don't care too much for
the extortionate pricing of replacements so it's sat in the basement
in bypass. The "Protected Sockets" are no longer 'protected'.

Keep an eye out for suitable replacements from RapidOnline when they are
doing a good deal or one of the other non ripoff merchants.

Avoid any that say "wheelchair" battery as they are typically cunningly
rebadged heavy duty deep discharge cells sold at 3x the normal price!

If you can match voltage, dimensions and Ah capacity you should be OK.

--
Regards,
Martin Brown

On Mon, 16 Jun 2014 12:16:23 +0100, Martin Brown
wrote:

On 13/06/2014 13:14, Johny B Good wrote:

I've run out of suitable SLAs for the UPS and don't care too much for
the extortionate pricing of replacements so it's sat in the basement
in bypass. The "Protected Sockets" are no longer 'protected'.

Keep an eye out for suitable replacements from RapidOnline when they are
doing a good deal or one of the other non ripoff merchants.

Avoid any that say "wheelchair" battery as they are typically cunningly
rebadged heavy duty deep discharge cells sold at 3x the normal price!

Deep cycle is what I'm after but not at 3x the 'normal' price (not
even at 'normal' prices after taking a gander at the Rapidonline
website).

If you can match voltage, dimensions and Ah capacity you should be OK.

No problems on size or AH capacities other than finding a matched set
of four 12v batteries. Since I didn't get the battery case half with
this UPS, I've used externally connected batteries. Initially a set of
36AH car batteries I blagged for 60 quid the lot which I stood on the
lower shelf of the angle iron shelving unit in the basement upon which
the UPS is perched.

I've supplemented this with sets of four 12v7AH SLAs and even a set
of four 12v 25AH SLAs mounted on a sheet of MDF hanging from bolts
underneath the top shelf and over the car batteries below.

As I said, the car batteries were the first to go bad and were
weighed in when I tried yet another set of car batteries which are now
sat there disconnected. The 25AH, along with the 7AH batteries
eventually went bad a few years later and the UPS is disconnected
until I can find another set of 25AH SLAs for 40 to 60 quid the set at
a major Radioham rally or flea market.

My best bet may be to set my sights a little lower and use the 7 or 8
AH batteries. It can be rather galling to think that whatever capacity
of SLA battery you choose, you'd be doing well to get 4 or 5 years
life out of the investment before you have to 'splash the cash' once
more.

The maintence costs in battery replacements alone, never mind the 35W
maintainance consumption of a SmartUPS2000, is rather high to achieve
autonomy periods measured in hours rather than minutes.

The obvious solution to hours long autonomy by using a petrol genset
is only workable with the more expensive inverter type of genset. An
ordinary 2.8KVA generator will grossly overvolt if it sees even a
modest leading current load. A 4.7uF PF correction cap was enough to
send the nominal 230v north of 270 volts and there's nearly 9uF's
worth in the mains input circuit of the SmartUPS2000 alone, before we
even consider that due to the protected loads themselves - no wonder
the poor UPS kept cycling endlessly between mains and battery power
when it was supplied by the genset!
--
J B Good

The obvious solution to hours long autonomy by using a petrol genset
is only workable with the more expensive inverter type of genset. An
ordinary 2.8KVA generator will grossly overvolt if it sees even a
modest leading current load. A 4.7uF PF correction cap was enough to
send the nominal 230v north of 270 volts and there's nearly 9uF's
worth in the mains input circuit of the SmartUPS2000 alone, before we
even consider that due to the protected loads themselves - no wonder
the poor UPS kept cycling endlessly between mains and battery power
when it was supplied by the genset!

Yes I've seen just that happening but the generator voltage measured on a true
RMS Fluke meter was indicated at 230 volts;!..


Just out of interest, reproduced below an excerpt of an RAIB report issued today
were a railway level crossing gate system didn't work. Fortunately nothing was
going thru the crossing at the time from the road vehicle direction..

A bit of malarkey with the power it seems and the UPS system. All originally
caused be a RCD tripping which wasn't needed as there were multiple earth's, so
it sez;!....




80. Network Rail issues guidance about UPS systems. The guidance acknowledges
that the batteries of a UPS system €˜are the most critical component and are
€˜perishable in that their performance will degrade over time. The guidance also
states that €˜manufacturers will provide batteries with a design life which will
often not be achieved. For example an 8-10 year battery will probably need
replacing after 7 years provided that maintenance and good temperature control
has been maintained. The batteries of the UPS system in use at Butterswood
level crossing had not been replaced since the system was installed around 20
years before the incident.


81. The signalling department whose responsibilities included Butterswood level
crossing had no plans to replace the UPS system batteries during the life of the
system. In fact, Network Rails knowledge about the condition of the UPS system
at Butterswood, including the age of its batteries, was incomplete until after
the incident on 25 June 2013.


The data logger


82. The data logger fitted at Butterswood level crossing had its own internal
UPS system, separate from the level crossings main UPS system. Normally the
data logger is powered from the main incoming network power supply and uses its
own internal batteries to provide back-up power in the event of a main power
failure for a maximum of 6 hours. The data logger is tested annually by
signalling technicians. The test involves pulling the main network power lead
out of the unit, and checking that the indications are still showing that the
data logger is operating correctly. Network Rail requires that the batteries in
the UPS systems of its data loggers are renewed at no more than 10 yearly
intervals.


For level crossing UPS systems, Network Rail required them to operate for 20% of
their expected performance.

The UPS system at Butterswood level crossing was believed to be capable to
operate for up to 12 hours, therefore the permitted performance time was 2.4
hours.


83. Records indicate that the batteries were replaced in 2012. This means the
batteries only lasted around a year before they failed. Information from the
data logger manufacturer suggested that the batteries may only last 5 years,
depending on how many channels the data logger is monitoring. It was the belief
of the local signalling and electrification and plant teams, that it was often
the case that new batteries can spend significant periods of time €˜on the
shelf in store rooms, and could thus be several years old before they are used,
sometimes leading to premature failure.
--
Tony Sayer