size of battery needed for my solar panel

ericmark said:

Watts = Volts x Amps x power factor, the latter in DC is 1, so amps = watts/volts so 45/12 = 3.75 amps. It is just simple maths now we know the unit being used.

Click to expand...

Granny and eggs, I think!

ericmark said:

* Power Converter Output Voltage: 12V
* Power Converter Output Current: 25A
So if the mains to 12 volts unit is 25 amps, then it can clearly run with a battery able to deliver 25 amps.

Click to expand...

There is no mains charged involed for me like the poster above. it will rely on battery solo

ericmark said:

If only wanting to spend a couple of hours then down to around 12 Ah. Deep cycling, a car battery, is not recommended, the active material will fall off the plated, so looking at a traction battery which in the main today are AGM (VRLA).

Click to expand...

I was told somewhere ells that the plates are all the same size now. will I need a greater amps/ hour if using a car battery then a leisure battery?


Found this one! its on offer

muckington said:

I was told somewhere ells that the plates are all the same size now. will I need a greater amps/ hour if using a car battery then a leisure battery?

Click to expand...

You should not be using a battery, at all, designed as a car battery. Car batteries, are designed to support a short, high current discharge, followed by immediate recharge. A leisure type battery, is designed for long slow discharge, then a full recharge - which is what you need. A car battery, will seem to work for a while, but will soon be wrecked by such treatment.

Reference to mains, was to show maximum draw, or start amps. Lead acid batteries come in a few flavours, the traction battery is designed to be deep cycled, and toped up, used in fork lifts and milk carts, the vehicle battery designed for high current, and the leisure battery halfway between.

But there is a new technology, the valve regulated lead acid or absorbed glass mat, these batteries are not flooded with electrolyte, they only just have enough, and are totally sealed could be used on their side, in fact in stair lifts they often are, but the charging needs a special charger as over-voltage will damage them. Used with all sorts from stop/start cars, mobility scooters, house alarms, from around 3 Ah to 110 Ah.

So flooded batteries (can be topped up with distilled water) can use any type of charger, but AGM needs a special type, the same problem with Lion batteries, sometimes the controller is built into the battery, but if not, the chargers can be expensive. As to the Lion battery you link to, since we don't know if the charge controller can be used with Lion batteries we can't advise.

In the main they are better, as can be left for years half charged, but depends what the charge controller says.

ericmark said:

Reference to mains, was to show maximum draw, or start amps. Lead acid batteries come in a few flavours, the traction battery is designed to be deep cycled, and toped up, used in fork lifts and milk carts, the vehicle battery designed for high current, and the leisure battery halfway between.

Click to expand...

Where would you recomend I buy such a battery from?

Local, I got last one from the main UK suppliers, but on reflection cost to collect, or transport costs, mean local is in the main cheaper, so local to me is Marks Autos in Welshpool, as to what is local to you I don't know.

ericmark said:

Local, I got last one from the main UK suppliers, but on reflection cost to collect, or transport costs, mean local is in the main cheaper, so local to me is Marks Autos in Welshpool, as to what is local to you I don't know.

Click to expand...

do auto factors sell them?

muckington said:

do auto factors sell them?

Click to expand...

Do you possess a telephone, and know how to operate it?

muckington said:

do auto factors sell them?

Click to expand...

Mine does, Bodelwyddan is not that far way, Tayna Batteries was Manchester Batteries in Abergele but seems taken over and moved twice at least. But 76 miles costs, and any postal service also expensive for batteries, and my local Mark's Autos in Welshpool will get me what ever battery I want by the next day, and by time you include postage or travel same cost as any other place to get it, and they will dispose of old battery for me. And I can pick up anything else I need at the same time, crock clips etc.

Come on, do we really need to tell you how to shop?