On Sunday, 28 June 2020 18:49:50 UTC+1, T i m wrote:
On Sun, 28 Jun 2020 10:11:50 -0700 (PDT), tabbypurr wrote:
On Saturday, 27 June 2020 20:16:24 UTC+1, T i m wrote:
On Sat, 27 Jun 2020 10:58:18 -0700 (PDT), tabbypurr wrote:
On Saturday, 27 June 2020 16:05:50 UTC+1, T i m wrote:
On Sat, 27 Jun 2020 07:22:11 -0700 (PDT), tabbypurr wrote:

true

Assuming you're charging a lead acid battery and it's not SLA, 5w is not enough to need a controller. A diode stops any discharge.

True, but it doesn't prevent any overdischarge of the battery?

yees

So not provided by a simple diode.

ICBA to explain the obvious

Yeah, right. ;-)

I refuse to believe you can't figure it out for yourself. And if you can't, life's too short for discussions that stupid. Sorry.

The trick is to find a LVD solution that doesn't draw any significant
current itself, or find one where the LVD draws far less than any
potential load.

A latching relay / circuit might be such and could be used to
disconnect itself and the load when the LV threshold was detected.


I don't recall the op requesting a discharge protecting relay.

He didn't specifically request a lot of things but did request general
advice.

If he wants one, I would not regard it as a trick in any way, just some basic electronics.

'Basic electronics' that provides the LVD function whilst not
consuming any power itself?

If you manage to invent electronics tht uses no power I'm sure the world will be curious.

I wasn't trying to, I was suggesting such didn't exist.

Do you have any other silly requests?

Do you have any other stupid statements (before you dig the hole
deeper and then hiding etc).

I merely pointed out your sudden invention of a new unrealistic imagined requirement was silly. It is.


A bistable relay can eliminate most of the current draw.

I know, I suggested it.

Drive it with a low current opamp, 2 transistors or fets & 2 big caps and Robert's your relative.

Schematic? ;-)

feel free.

No, you were the one suggesting it was fixable with some 'basic
electronics'? You tell me what they are (before you confirmed such
didn't exist etc).

I've given enough info for anyone competent at electronics to go do it. If you want to me give a tutorial for folk that aren't, too bad.


The point was, whilst a simple series diode can negate any self
discharge by the panel (and should be built into most panels in any
case),

There are sound reasons why they aren't.

I know. I was talking of the sort of panel sold to maintain a 12V
battery.

If you run panels in series you don't benefit from multiple V drops.

Agreed.

There are also ways to prevent discharge that don't drop a volt or so under load.

There are?

yes, like FET rectification, or even more basic using a schottky. If you don't know this stuff why are you arguing about electronics?

a big hole many fall into is wrecking a perfectly good /
expensive battery by over discharging it.

Yes. And some are more careful.

Of course? Duh!

And in some situations it's better to run it low on infrequent occasion than cut off early etc.

Of course ... other than for the lifespan of the battery (with LA
specifically). I'm not sure the OP is thinking on running some life
support kit off this solar panel. ;-)

I would seriously hope no-one designing or using life support equipment would be running it off a battery that they let go flat.


So, it might be considered
'better' to have a less efficient system that protects the battery
than a more efficient one without.

The OP was looking for feedback from people who had experience of the
items he referenced, and I have ... and one of the 'virtues' is that
they typically protect the battery from over discharge.


It's hard to know what the op wants without enough detail.

Indeed. ;-)

Cheers, T i m

NT