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#26

Bogger
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Joined: 01 April 2016
Posts: 1,538
Member
10 August 2018 08:52 am

Golden oldie your battery man informed you well thumbsup The only thing the same about them all, is they are 12 volt rated. How they deliver power, the applications they are designed for and even the manner and voltages used to re charge are all different. Hence 7 and 8 stage chargers now common place. Manner of use and charging are probably two of the main factors that effect the batteries life and their not a cheap item. The "old type" battery charger is long dead, in fact it won't even put out voltage high enough to fully charge a deep cycle battery. This is why they as in deep cycle batteries and other types don't perform that well just plonked in the back of vehicle without the correct controller, as the average vehicle alternator just doesn't pump enough voltage to ever fully recharge it. yikes

2 users like this post: Simmo, Gem in I

#27

Nightjar
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Joined: 26 September 2013
Posts: 655
Member
10 August 2018 11:54 am

A good friend of mine (Boobook) gave me some valuable advice and I now swear by it.
Bought a fold up twin solar from ebay which come wired parallel putting out 3.5 amps approx.
Wired the same panels in series and now have 7 amps topping battery up.
The down side of this I had to upgrade the solar controller to handle double output.

https://www.outbackmarine.com.au/blue-s … t3EALw_wcB

Have now series wired the two panels on roof of caravan.
No more battery problems and rarely ever have to run generator.


Happy Hunting, Nightjar.

2 users like this post: RM Outback, Gem in I

#28

moeee
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From: St Albans, VIC
Joined: 29 June 2018
Posts: 218
Member
10 August 2018 12:44 pm

Nightjar wrote:

A good friend of mine (Boobook) gave me some valuable advice and I now swear by it.

What was the advice ?
Was it to alter the original parallel connected panels to series connected panels ?

If that is the case , how would it help ?
Would it work better when lesser sunlight is available like on an intermittent cloudy day?


You can choose your friends but you can't choose your enemies

#29

Bogger
Member
Joined: 01 April 2016
Posts: 1,538
Member
10 August 2018 02:34 pm

Nightjar wrote:

A good friend of mine (Boobook) gave me some valuable advice and I now swear by it.
Bought a fold up twin solar from ebay which come wired parallel putting out 3.5 amps approx.
Wired the same panels in series and now have 7 amps topping battery up.
The down side of this I had to upgrade the solar controller to handle double output.

https://www.outbackmarine.com.au/blue-s … t3EALw_wcB

Have now series wired the two panels on roof of caravan.
No more battery problems and rarely ever have to run generator.

Nightjar that has me confused ?
Wired parallel as the panels were standard, the amps should be higher ? In series the voltage will be higher but amps lower than the same panels wired in parallel? So when you say the upgraded controller handles it? You mean the 24 volts which is what you would get wiring two 12 volt panels in series ?
Two 12 volt panels 10 amp in series would be 24 volts 10 amp . The same two panels wired in parallel would give you 12 volts 20 amps ?
I might be totally wrong here ops but just hate to see people pumping 24 volts thru their 12 volts systems and controllers .................. nasty result yikes

Last edited by Bogger (10 August 2018 02:37 pm)

1 user likes this post: Simmo

#30

moeee
Member
From: St Albans, VIC
Joined: 29 June 2018
Posts: 218
Member
10 August 2018 02:46 pm

Bogger wrote:

I might be totally wrong here ops but just hate to see people pumping 24 volts thru their 12 volts systems and controllers .................. nasty result yikes

Nightjar seems to be very happy with his current circumstances.
But you musta went to the same school as me Bogger - (but paid more attention)


You can choose your friends but you can't choose your enemies

#31

Wally69
Member
From: Sydney
Joined: 13 December 2013
Posts: 2,828
Member
10 August 2018 03:21 pm

Hey Chris, you questioned the current tech v’s what you have. Just tested mine, it is about the same size but is a 20w panel, so looks like they have doubled the realestate efficiency between ours and a 120w panel looks about 3 times as big.

1533873265_f6f5c8b6-47bf-4692-87cb-0c0d7bfbcfec.jpg
1533873286_2292ef4d-3df9-4997-aa49-a768881ce4c4.jpg

Mine is rated about 1.2A but tested at 0.67A at 19v in the winter sun. Based on the calculations a couple of posts up, your two combined should be about the same. Real question is what will it store in a normal day based on those figures and what can it drive. I got mine to run a LED strip light and charge the SDC batteries overnight. I have a handful of 12v 45w 10min rated computer server batteries to hook up to it but haven’t given it a good test run to see if it is reliable.

An upgrade for me would be enough juice to keep a fridge cold and do the above, already have a 36Ahr Engel battery for the job. I assume it would take the existing panel 0.67A x 19v/12v x 8hrs = 8Ahrs/day or about 5 days to charge it. My fridge will flatten it in 2, so would need 50w at a minimum. Upgrading at 120w and a higher capacity battery makes sense to me as it always rains when I head away.

1 user likes this post: ChrisM

#32

ChrisM
Member
From: Sydney, NSW
Joined: 28 January 2013
Posts: 577
Member
10 August 2018 04:48 pm

Nightjar wrote:

A good friend of mine (Boobook) gave me some valuable advice and I now swear by it.
Bought a fold up twin solar from ebay which come wired parallel putting out 3.5 amps approx.
Wired the same panels in series and now have 7 amps topping battery up.
The down side of this I had to upgrade the solar controller to handle double output.

https://www.outbackmarine.com.au/blue-s … t3EALw_wcB

Have now series wired the two panels on roof of caravan.
No more battery problems and rarely ever have to run generator.

Hi Nightjar
I just contacted my auto elect and explained what you said to him.
he confirmed to me that you are correct in what you say.
In simple terms when in series you have higher voltage and lower [or constant] amps
When in parallel you have lower [base] voltage and higher amperage.
Theres something more to think about. never thought about it that way
thank you for your input . taken onboard
Cheers
ChrisM


Of all the things I've lost......I miss my mind the most.

#33

moeee
Member
From: St Albans, VIC
Joined: 29 June 2018
Posts: 218
Member
10 August 2018 05:10 pm

This thread is reminding me of the GREAT Film - "A Few Good Men" where Jack Nicholson says "YOU CAN'T HANDLE THE TRUTH"

Sometimes too much knowledge can be dangerous.


You can choose your friends but you can't choose your enemies

1 user likes this post: Goldchaser1

#34

Simmo
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Joined: 08 November 2014
Posts: 820
Member
10 August 2018 05:28 pm

You must not have explained it properly to your auto-lecky, or you need a new one!

Where Nightjar is mistaken is putting the two panels in series gives 7 amps, that is incorrect.

Nightjar is talking no doubt about a good MPPT charge regulator, that you could indeed wack between a 24v panel and a 12 v battery.

However, a 12v panel rated at say 24 watts, or 2 amps, in parallel with another, 12v/24 watt panel would give 12v at 48 watts, or 4 amps.

Wire them in series, you will get 24 volts, at 24watts, and 2 amps... but feeding 24 volts into an mppt regulator connected to a 12v battery, will convert that back to 12 volts, and double the current, as the load is the same. (V=IR) so minus inefficencies in the regulator, you will be back to 4 amps.... maybe..


Age doesn’t matter – unless you are a cheese.
Ken Dodd

1 user likes this post: Bogger

#35

Simmo
Member
Joined: 08 November 2014
Posts: 820
Member
10 August 2018 05:31 pm

Haha! even my comment is wrong!!
24v @ 24w is 1 amp!! So after conversion, we are back to 2 amps...


Age doesn’t matter – unless you are a cheese.
Ken Dodd

#36

Goldchaser1
Member
From: Kalgoorlie, WA
Joined: 28 February 2017
Posts: 455
Member
10 August 2018 05:49 pm

Crism its all over the net how series and parallel differ,fairly basic but simmos on the money,ya wont double amps by going in series,your doubling voltage(with 2 panels) and that should be slightly more effecient threw a good controller but its impossible to double the amps by going from parallel to series..... big_smile big_smile big_smile

PS:those panels look like miget twister boards....

Last edited by Goldchaser1 (10 August 2018 05:51 pm)

3 users like this post: Bogger, Simmo, ChrisM

#37

Bogger
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Joined: 01 April 2016
Posts: 1,538
Member
10 August 2018 05:52 pm

hmm I must be in the naughty corner yikes big_smile big_smile

Last edited by Bogger (10 August 2018 06:45 pm)

#38

Simmo
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Joined: 08 November 2014
Posts: 820
Member
10 August 2018 05:54 pm

I think where the idea works good, is if you can get one of those house panels, that are like 24v 160 watt or something...
Wack one of them into a good mppt and to a 12v battery and you have 320 watts @ 12v!!!


Age doesn’t matter – unless you are a cheese.
Ken Dodd

#39

ChrisM
Member
From: Sydney, NSW
Joined: 28 January 2013
Posts: 577
Member
10 August 2018 05:55 pm

Simmo wrote:

You must not have explained it properly to your auto-lecky, or you need a new one!

Where Nightjar is mistaken is putting the two panels in series gives 7 amps, that is incorrect.

Nightjar is talking no doubt about a good MPPT charge regulator, that you could indeed wack between a 24v panel and a 12 v battery.

However, a 12v panel rated at say 24 watts, or 2 amps, in parallel with another, 12v/24 watt panel would give 12v at 48 watts, or 4 amps.

Wire them in series, you will get 24 volts, at 24watts, and 2 amps... but feeding 24 volts into an mppt regulator connected to a 12v battery, will convert that back to 12 volts, and double the current, as the load is the same. (V=IR) so minus inefficencies in the regulator, you will be back to 4 amps.... maybe..

Thanks Simmo
Im probably to blame for giving out the wrong information to the lekky.
Electrical stuff just frys my brain. Hence the reason for this post. I Just Dont Get It yikes
Its like some sort of wizardry and black magic combined.
Im still trying to ascertain if its worth keeping/updating the system for the amount of power it generates or just scrap it and move along.
Cheers


Of all the things I've lost......I miss my mind the most.

1 user likes this post: Gem in I

#40

Simmo
Member
Joined: 08 November 2014
Posts: 820
Member
10 August 2018 06:25 pm

ChrisM wrote:

Thanks Simmo
Im probably to blame for giving out the wrong information to the lekky.
Electrical stuff just frys my brain. Hence the reason for this post. I Just Dont Get It yikes
Its like some sort of wizardry and black magic combined.
Im still trying to ascertain if its worth keeping/updating the system for the amount of power it generates or just scrap it and move along.
Cheers

All good bud!
I think the short circuit current test will make your mind up mate. Your sparky will have one of them for sure.


Age doesn’t matter – unless you are a cheese.
Ken Dodd

#41

Goldchaser1
Member
From: Kalgoorlie, WA
Joined: 28 February 2017
Posts: 455
Member
10 August 2018 06:32 pm

ChrisM wrote:
Simmo wrote:

You must not have explained it properly to your auto-lecky, or you need a new one!

Where Nightjar is mistaken is putting the two panels in series gives 7 amps, that is incorrect.

Nightjar is talking no doubt about a good MPPT charge regulator, that you could indeed wack between a 24v panel and a 12 v battery.

However, a 12v panel rated at say 24 watts, or 2 amps, in parallel with another, 12v/24 watt panel would give 12v at 48 watts, or 4 amps.

Wire them in series, you will get 24 volts, at 24watts, and 2 amps... but feeding 24 volts into an mppt regulator connected to a 12v battery, will convert that back to 12 volts, and double the current, as the load is the same. (V=IR) so minus inefficencies in the regulator, you will be back to 4 amps.... maybe..

Thanks Simmo
Im probably to blame for giving out the wrong information to the lekky.
Electrical stuff just frys my brain. Hence the reason for this post. I Just Dont Get It yikes
Its like some sort of wizardry and black magic combined.
Im still trying to ascertain if its worth keeping/updating the system for the amount of power it generates or just scrap it and move along.
Cheers

Agree,it can get confusing sometimes
Id update,a 100-120,depending on what ya can fit up there would cost prob about $150-200 odd if ya shop about on ebay with a good controller,run rings around those old ones......
The victron mppt little blue controllers are top quality for the $$$,75/10 would be the one to look at....
https://rover.ebay.com/rover/0/0/0?mpre … 1421859614
https://rover.ebay.com/rover/0/0/0?mpre … 2636055484

4 users like this post: Simmo, Bogger, ChrisM, Gem in I

#42

Nightjar
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Joined: 26 September 2013
Posts: 655
Member
10 August 2018 06:48 pm

moeee wrote:

What was the advice ?
Was it to alter the original parallel connected panels to series connected panels ?

If that is the case , how would it help ?
Would it work better when lesser sunlight is available like on an intermittent cloudy day?

Yes, what I wrote above! They come wired parallel I wired them in series.
My apologies, the voltage doubles but amperage remains the same but more efficient through the MPPT.
Was going to correct mistake in post #27 but the edit button has disappeared.
***My tutor gave me a slapping. *** tongue

Last edited by Nightjar (10 August 2018 07:05 pm)


Happy Hunting, Nightjar.

4 users like this post: Simmo, moeee, Bogger, Gem in I

#43

iamagoldenoldie2
Member
From: south west Sydney
Joined: 07 August 2016
Posts: 346
Member
11 August 2018 12:13 am

Bogger, the old battery chargers are still useful, the modern multi stage chargers read the battery condition then start to work but if the voltage is too low Iget the error message battery failure, so I hook the dead battery top to toehold charger switch it on and not much happens, its pumping about 1 amp into the dead battery, then something miraculous happens after 3 hours its pumping about 4 amps into the dead battery , it takes a while to kick start the charging process now with the little sealed lead acid batteries I used to hook up a 12volt bulb with a potentiometer in line and set charting at 1/2 amp that way I didn't cook the battery I have some old very very heavy sealed lead acid batteries yashyua brand ex telecom 6 volters 110 amp hour they were 7.6 volt 6 years ago stored and forgotten tested voltage 3.1 so my charging technique has brought them back to 5.8 volts good for my led lights there is a wealth if information in the forum you just need to look at the suggestions old 12 volters were charged at 13 .5 volts newer batteries need about 14.5 volts and lithium iron a tad more so don't throw the older charges away,,, parallel and series wiring is another mind bender

#44

ChrisM
Member
From: Sydney, NSW
Joined: 28 January 2013
Posts: 577
Member
11 August 2018 12:22 pm

Thanks for all the comments so far everyone. Im slowly getting my head around this “series” v “parallel” caper [well sorta,kinda]. This morning I went out and got a new multimeter capable of reading amps. AND a quick thank you to the guy who overheard my confused explanation about what I was trying to do and explained to me step by step on how to set up and read the Amp output. So I set it up first thing this morning and now waiting for the sun to hit the panels this arvo.
I’m going to try everybody’s patience one more time and see if we can work out a project specific result.
OK. What is the purpose of these solar panels, why do I “think” i need them and what will they be maintaining. AND.....yes my cute little “midget twister board” panels are getting scrapped. The ones that Wally69 suggested are very close to the size that can fit in the existing housing.
The receiver is a Century N70T 100Ah Deep Cycle currently hooked to the start battery Century N70ZZX 810CCA through some sort of smart switch, so its being topped up while the car is running. From the Deep Cycle side I will be using power for LED lights, detector batteries ,an inverter {possibly 1000W} phone and laptop ...and whatever other smaller units that need charging.
In my simple reasoning the demand on the battery is not great because it’s not a constant demand but running it flat is not a healthy thing......so enter the solar panels as a “Top Up”.
The car can be parked for 2 or 3 days without being moved and with the only load being the 80L Kings fridge {in most cases}.
The panels are mounted permanently to the front of the roof rack {not Ideal I know} but it saves the need to carry larger panels for short trips and doesn’t take up valuable space1533950378_20180811_102926.jpg
1533950378_20180811_103033.jpg
1533950378_20180811_110843.jpg.
So....after this long winded explanation i need to know if using 2 new replacement {1.2A] panels will have a “reasonable” ability to top up the deep cycle over a period of time.
As confused as I sound about this {which I am} In a nut shell is the power generated going to be worth the effort of setting it up?
Cheers
ChrisM


Of all the things I've lost......I miss my mind the most.

#45

Jaros
Moderator
From: S.E.Qld., QLD
Joined: 11 August 2013
Posts: 7,657
Moderator
11 August 2018 12:45 pm

Probably not mate. But think what you have learned during this exercise. Modern panels are so much more capable and lightweight as well. tongue


Lottsa hope :F1A4M2, Exterra 705 Gold, Ace 250,Aldi detector, ? detector,Garmin Etrex30, 2 sieves,2 pans,2 sluices, Nugget sniffing Cocker Spaniel. X-Pointer PI by Deteknix, Jobe Knife, Leschke Shovel, Pro-swing 45 Harness, Treasuremate 11 Amp.Gurney gusunder. VK4NLS

3 users like this post: ChrisM, Simmo, Gem in I

#46

moeee
Member
From: St Albans, VIC
Joined: 29 June 2018
Posts: 218
Member
11 August 2018 01:23 pm

What is that Coffin looking thing in your pictures ?
How come in the first 2 pictures it is a shiny black colour and in the 3rd picture it is dirty white colour ?


You can choose your friends but you can't choose your enemies

#47

Occasional_panner
Member
Joined: 20 July 2016
Posts: 1,823
Member
14 August 2018 05:10 pm

I wouldn't bother with those, just toss them and start again.

Something to consider is that you'll need to park in the sun and probably move the vehicle many times to chase the sun.
Usually a pain considering where you are and terrain/trees.

Most situations these days to top up a battery that runs a fridge and lights etc needs 140-160 watts minimum, so you're way short on power with those.

PWM (pulse width modulation) controllers just connect the panel direct to the battery, as the battery voltage rises they cut in and out with the feed so not to overcharge the battery.

MPPT (multi point power tracking) uses a dc dc converter and brings in the full voltage and converts that to the charge voltage, this is more efficient, but only worth while when you are talking of a reasonable size system, I personally wouldn't bother unless you are running 250w +
The other advantage of mppt is you can run a 24v panel, which in fact has a maximum amperage at around 30v, open circuit of around 35, feeding a higher voltage through a line 20-30m away isn't such a big deal then, you won't get anywhere near the voltage drop through the line. The incoming voltage to the regulator will be converted close to the battery to 12 v and losses will be minimal compared to running the same length cable with a 12v panel and a pwm controller.

Even better run two or three 24v panels in series through an mppt, then line losses would be .5-1%
This chart helps as a reference.
1534227000_dcp4.jpg

2 users like this post: Jaros, ChrisM

#48

Occasional_panner
Member
Joined: 20 July 2016
Posts: 1,823
Member
14 August 2018 05:17 pm

moeee wrote:

A 12 volt battery is pretty much a 12 Volt battery.

Picture a 5 gallon bucket and a 44 gallon drum , each full of water with a tap on 'em.
They only pour out water the same , depending on how far you open the tap.

You also need to consider the discharge rate, or C rating, some can handle feeding 100amps an hour, other far less or far more, get this wrong and you'll stuff your batteries in one trip.

#49

Jaros
Moderator
From: S.E.Qld., QLD
Joined: 11 August 2013
Posts: 7,657
Moderator
14 August 2018 05:37 pm

O.P. that formula wheel is always handy to have around. I have one on my Radio room wall as well as the frequency charts for all Hamm bands and 80 UHF channels as one of my 2way handheld radios is calibrated in frequencies only.


Lottsa hope :F1A4M2, Exterra 705 Gold, Ace 250,Aldi detector, ? detector,Garmin Etrex30, 2 sieves,2 pans,2 sluices, Nugget sniffing Cocker Spaniel. X-Pointer PI by Deteknix, Jobe Knife, Leschke Shovel, Pro-swing 45 Harness, Treasuremate 11 Amp.Gurney gusunder. VK4NLS

#50

moeee
Member
From: St Albans, VIC
Joined: 29 June 2018
Posts: 218
Member
14 August 2018 06:30 pm

Occasional_panner wrote:
moeee wrote:

A 12 volt battery is pretty much a 12 Volt battery.

Picture a 5 gallon bucket and a 44 gallon drum , each full of water with a tap on 'em.
They only pour out water the same , depending on how far you open the tap.

You also need to consider the discharge rate, or C rating, some can handle feeding 100amps an hour, other far less or far more, get this wrong and you'll stuff your batteries in one trip.

The guy was getting overwhelmed with the information presented and wanted it in simple layman terms


You can choose your friends but you can't choose your enemies

1 user likes this post: Gem in I

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