Solar Expert needed

Submitted: Wednesday, Jul 13, 2005 at 14:29
ThreadID: 24683 Views:2543 Replies:4 FollowUps:4
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Solar Panel information needed. I have just inherited a small solar panel from an installation we have pulled out at work.
It is

Solarex Model SX-40U

The question is this a 40 Watt unit & is there a regulator built in.
Looking at using it on the camper trailer as a back up to the 100 AH battery that is charged from the car.
Thanks for the information I know you will supply

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Reply By: Mainey (WA) - Wednesday, Jul 13, 2005 at 15:10

Wednesday, Jul 13, 2005 at 15:10
it is a discontinued model, it is 40 watts and has no inbuilt regulator.
Yes, you could use it to 'assist' the charge of a 100a/h battery, BUT it will not replace the power used by a fridge, it will slow the discharge of the battery and will give you some inclination of how solar will work for you, if you use it while the fridge is also connected you could get away without a regulator, but don't disconnect the fridge from the system as it may cook a battery when there is no drain on the battery, use a reasonable battery guage (multymeter) to keep an eye on the power delivered into the battery when the panel is in full sun and fridge is off, keep it below the maxium specified for your specific battery.
welcome to the solar world :-)
AnswerID: 120148

Follow Up By: Vince NSW - Wednesday, Jul 13, 2005 at 15:18

Wednesday, Jul 13, 2005 at 15:18
Thanks Mainry.
It's funny you should say that it could cook the Batttery. The installation we had it in was a remote Web cam and the battery was bone dry when we had a look. Could I fit an external regulator ?
FollowupID: 375197

Reply By: Mainey (WA) - Wednesday, Jul 13, 2005 at 16:24

Wednesday, Jul 13, 2005 at 16:24
but before you go and buy a low priced solar regulator use the panel without one first and see if you will want to invest in a similar sized or larger panel as well to add to the 40w you have now, get the feel for how it will work for you and if you are happy with it's performance etc.
You buy a solar regulator based on your panel output, so what you get for a 40w panel will not be any good when you add another panel to the system if you initially buy a low rated reg now.

I used an 80w Solarex panel for about eight years without a regulator with no problems, however I always had a fridge connected to the batteries.

There is so much to be learned about your charging system from a decent regulator as they show the individual volts, amps, and individual totals over a given time, and also where the power is being used and has also come from all shown in their LCD display, the better ones with all the 'fruit' cost $230, but IMO are definitely worth the added cost.
Check out the “Steca PR” range at the link below

AnswerID: 120164

Follow Up By: Photoman - Wednesday, Jul 13, 2005 at 17:25

Wednesday, Jul 13, 2005 at 17:25
There are some quite good regs on ebay for around $140, look to have all the fetures you could need. And could easly handle more panels if needed... I 'm in the process of building my own systm for a camper trailer
FollowupID: 375223

Follow Up By: Mad Dog (Australia) - Wednesday, Jul 13, 2005 at 22:49

Wednesday, Jul 13, 2005 at 22:49
Mainey, when you get a big url like that try
that url converts to this,
I don't really want to buy a wider screen :)
FollowupID: 375309

Follow Up By: Mainey (WA) - Thursday, Jul 14, 2005 at 14:22

Thursday, Jul 14, 2005 at 14:22
Thanks Mad Dod,
have added it to my links as requested
gee, maybe I'm not too old yet, it worked for me! :-)
FollowupID: 375404

Reply By: Member -Dodger - Wednesday, Jul 13, 2005 at 17:33

Wednesday, Jul 13, 2005 at 17:33
Your panel will only put out about 2.8 amps on a good day so if your battery is connected and the fridg running then there is no worry. It will not fully supply the fridg at all times but will certainly maintain your battery for at least 3 days provided that there is plenty of sunlight and you only run a compressor type fridg and one versa light orthe like.
I used to have a handle on life, but it broke.

Cheers Dodg.

Lifetime Member
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AnswerID: 120174

Reply By: 4X4Treker - Wednesday, Jul 13, 2005 at 21:55

Wednesday, Jul 13, 2005 at 21:55
If you are looking for a good low cost regulator for the solar panel Jaycar Electronics have one that would suit your 40 watt panel for less than $30.00 I have used this type of regulator with no problems at all Catalog number is AA-0348 and is capable of 5 amps more than double what your 40 watt panel will output.

AnswerID: 120249

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