Thread: solar chargers from ebay......

Thanks guys....I liked the idea of the digital display which told me what was coming and going from the battery.....
But I guess I'll just use a multi meter.......one of those simple ones will get me out of trouble and I can still plug in the extra two panels when I'm away.....and its within my budget.......

Too easy......I'll avoid the fake ones and save up for the real ones.....

edit, this was in reply to bee utey not defenderzook

I would suggest that it might not.

not because of amps but because of the differential panel output in parallel/serial thing.

for a budget MPPT regulator on a 140w panel I dont think youd have any complaints about that one.

I have 2 of these in use.

20A 12V 24V MPPT LCD Solar Energy Charge Controller Regulator 15 30 More Power | eBay

I leave them permanently connected and think they are pretty good value. I'm impressed with the alloy case and connectors build quality ... can't comment on the electronics ... know nothing about that side of thinks - but they seem to work as promised.

Originally Posted by Blknight.aus

I would suggest that it might not.

not because of amps but because of the differential panel output in parallel/serial thing.

for a budget MPPT regulator on a 140w panel I dont think youd have any complaints about that one.

The panels I've got are all the same........and I plan to connect them all in parallel........
so the voltage won't change.......only the current will increase when I connect the two extra ones.......

Is that what you meant......?

Originally Posted by DEFENDERZOOK

The panels I've got are all the same........and I plan to connect them all in parallel........
so the voltage won't change.......only the current will increase when I connect the two extra ones.......

Is that what you meant......?

it depends on the panels.

if you have panels in series or parallel and one of the panels is shaded it not only drops the output by what its no outputting but also drags down some of the output from the other panels.

on those very cheap regulators on very cheap panels I usually run one panel per regulator. in your case I would have one on the vehicle mounted panel and a seperate one for the remote panels (which I would build into a breakout box so you could plug the panels into different things if needed.

alternates include
blocking diodes (for parallel)
bypass diodes (for series)
switches (so you have either the permanent panel hooked up or the externals)

Some panels come preset with diodes and how they are setup is usually listed in the manual or circuit diagram with the panels

http://www.solar-facts.com/panels/panel-diodes.php

thats a basic of why you use the different diodes. the problem with doing blocking diodes is that you need to push an extra .3 or .7v out of the panel to deal with the loss across the diode (a silocone diode drops .7v a germanium .3 and a schottky .2)

If you were going to go multiple panels on one input If the panels arent already fitted with blocking diodes ID put one of these for each input onto the regulator as close to the regulator as I could get it.

"...............any advice or info will be greatly appreciated as I'm starting to confuse myself from too much research........."

or as they say "bull**** baffles brains"


You're on the right track Tony, a point to remember is that ALL solar controllers are PWM (pulse width modulation) controllers but not all are MPPT (maximum power point transfer) controllers. Forget about voltage and current for a minute and consider that the whole point of the solar setup is to transfer power from the solar panel(s) to the battery. Using an MPPT controller allows this to happen more efficiently ie. the MPPT controller allows more power to be extracted from the panels than would be the case with a non MPPT controller. This is pretty handy especially when you're a bit light on for solar panel output but for keeping a battery 'topped up' not really important.

What is very important for a 'top up' solar charger is reliability. It's been my experience that when solar regulators fail their voltage output goes high and by the time you find out your batteries are boiled dry and ruined. This happened to a friend of mine whose cheap POS Chinese reg failed and took out a pair of 100 ah deep cycle batteries. I've had two solar regs fail and both have 'gone high' in output voltage but were discovered before damage could be done. Both were $40ish Chinese eBay solar regs.


.....would you know if it stops the power backfeeding to the panels in the dark....?
since it will be connected 24hrs......

....and I can still plug in the extra two panels when I'm away....

Not a problem, you can kill two birds with one stone here.

Permanently fit one of your panels to your Landy using a good quality reg like the one Beeutey suggests (Morningstar are also very good) and fit a diode in series between the panel and the reg. to block reverse current.

Connect your two other panels as required, (also with blocking diodes) in parallel to the same solar input connection as the permanently wired panel.

The diodes protect the panels from inadvertent reverse polarity connection, stops night time discharge and will prevent reverse current flow in a shaded panel when the other(s) are in sunlight.

Some panels come with the diode(s) already installed in the connector block.

For best results the panels should have the same electrical characteristics and the solar reg should be able to handle the maximum possible current the combined panels can put out.


Deano

What is your opinion on this regulator? It appears to suit both lead and lithium batteries.

http://pages.ebay.com/link/?nav=item...d=261599213144

Aaron

dont forget to try other sources online...

eg:

"ali express"

watch the numbers required and postage but otherwise normally theyre good.