Recommend a lead-acid charger?

Oct 27, 2014 39 Replies

Depends a lot on the value of "done".

A fully discharged 12v lead acid battery will freeze at 0C. One holding a 20% charge will freeze at about -8C.

Nasty winter weather is exactly the sort of time when you tend to forget about batteries a long way from the house.

Of course you might live in a sub-tropical climate & don't need to worry.

Quite likely. But 13.8v was and is the magic figure for charging SLA. And you won't go far wrong using this for wet types too.

For "topping charging" but just about everything I can find from manufacturers/suppliers still recommends limiting the current during the initital stage for a discharged cell; and then a lower voltage for the float charge (c. 13.5V for 6 cells). And given "smart" chargers are so cheap these days I am unclear why anyone would just use a constant voltage.

I live in Devon - it's relatively mild here, but we did get 2 weeks of

-8 a couple of years ago (killed my olive trees and a lot of the local torbay palms died off too)

My plan is to put them in a nice insulated box when I finally have them in the garden full time. It won't be perfect, but will do until I can move them into the shed and hopefully I'll never leave a fully discharged one down there!

Cheers,

Gordon

Chances are your charger will limit the current anyway - unless you're talking about a tiny battery. A lead acid has such a low impedance that you'd need a massive charger to push 13.8v into it.

Is this the tronic T4X?

Mine still switches on and senses wrong polarity but pressing the charge button doesn't cause it to cycle through the charge routines, it may only be a small fault but I haven't opened it to look yet. At the price I'd still buy another.

AJH

I had one like that. Opened it and found the button didn't make contact. Soldered in a new one.

It's most likely the button switch itself.

Are there figures showing available power from e.g. a "200 watt" solar array exposed only to blue sky (sun never strikes it) or only to white clouds, in summer (and in winter if that makes any difference) ?

Mostly I'm just curious, though if threatened power cuts became a reality I might start thinking about what I could do with 4 watt LEDs and battery power.

Are you saying it points North? what latitude?

All day in winter is roughly the same as the peak hour of the day in summer.

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you might get as little as 10-15 Watthours each day out of a 200W panel this time of year if it points North, so 2-3 hours running your torch...

I would think you may get about 40 watt hours if the panel is horizontal.

Why no sun on it, if its shaded all bets are off.

If I got a solar panel, the only place I could put it would be in a garden surrounded by walls and buildings such that the sun virtually never strikes the ground directly. So it would point not north but just vertically.

Obviously very far from optimum, but I was wondering just how bad it might be.

Thanks; I'll take a look.

So maybe a 1 watt LED !

Yes, almost completely shaded except from the sky directly above (and the sun is never in that position).

Well if its free then you can play at putting mirrors on buildings to try and get it to work.

A £15 SLA battery will light a 1W led for about a week before you need to take it a charger.

I've opened it up, seems to have 4 soldered contacts, the two left ones have permanent continuity as do the two right ones but no continuity L to R even when the button is pushed. It is 6.2mm square

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seems to be a lookalike match but no circuit diagram given for the contacts.

Any ideas?

I doubt my hand is steady enough or eyesight good enough to play with surface mounts but worth a try.

AJH

lidl/aldi battery charger repair

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Thanks Mark, I had to ask the IT bloke at work to do the soldering but all working now.

I could do with 5 more for the welfare buses at work, they have circuit protection that cuts the peripherals at about 12 Volts but a few days and the immobiliser drains the last few volts.

AJH

good one more saved from landfill I see they have a new model of that charger now hope it has a more robust switch

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I'm looking out for when it next comes on offer

AJH

Aldi or Lidl (can't remember which) had them a month or so back, and I have seen the odd one still sitting around in the pile of odds and ends left from old offers within last couple of weeks (might even be reduced).

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