Trevors

Hello people,
I would like to build the following projects:
http://www.talkingelectronics.com/pr...tInverter.html

and

http://www.talkingelectronics.com/pr...larCharger.htm

Would I simply connect the charger and inverter to the battery and put a diode on the output of the charger circuit? Also, I would like to use a 12v 6AH battery. I would ideally like the light to last at least 4 hours. Would this charger be adequite assuming 8 solar cells?

ericgibbs

I cant get your second link address, searched the 'home' page cant find which charger it is... please repost.

EDIT:
Is it this one.?
http://www.talkingelectronics.com/te...ive_index.html

__________________
Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

Trevors

Hi Eric,
Not sure what happened there but if you go down the list, It's the Solar Charger below 'Sky Writer'

ericgibbs

hi,
Finally found it.

For the invertor, assume 100% conversion with a 240V/40Watt lamp load, it would draw about 3 amps, so a 6AHr battery would last just under 2 hours.

Usually conversion eff is around 80%, so I would estimate 1.5 hours for a fully charged battery. End voltage not less than 10.8V.

IIRC,the output of the charger at 12V is only a few tens of milliamps, say 24mA.
Recharge time at 100%, 6/0.02 = 300 hrs!!!

I will re-examine the charger, Ill will come back if I have made an error in reading it.

Where are you in SA.?

__________________
Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

Trevors

Good old Johannesburg. 300 hours! I will look at other chargers. I was simply looking into solar energy to reduce electricity consumption. (Because of our current supply problem)
Txs for your quick response.

ericgibbs

Hi,
Look at the 12V, 12Watt Solar charger panels.

I used candles in Port Elizabeth during power failures.

__________________
Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

mneary

If domestic power is good for 164 hours a week and you only have to bridge 4 hours, you could start by reducing the fluorescent inverter to one lamp, or 20W. This doubles the 6AH battery to 3 hours. A reduction in current (brightness) could save a little. A second battery would fix it for sure.

You could use domestic power (I know it's not green) to supply the battery with 50 mA (that's not much) which would recharge it between blackouts. You could schedule your recharging when the system is lightly loaded (midnight to 6AM?).

If you need to use solar power, I would assume no more than 4 hours at full power on each sunny day. Thus you'd use a solar panel of at least 2.5 watts. The one in the article is 100 mW.