solar panel directly to battery

[justlikethat]

Hello,
My controller doesn't work anymore. Can I temporary connect the 600w solar panels directly to the battery to charge it? Will monitor closely with a voltage meter.

 

[ianlloyd100]

As with all things Solar..... It Depends... Higher voltage panels will hurt the battery. Imagine shoving up to 100v straight into your battery?. series connected panels will cause problems. Best to avoid doing this I believe..

 

[justlikethat]

Got them I'm parallel at 19v or so

 

[Forbisher]

Got them I'm parallel at 19v or so

You dont give enough info.
Were you still using that $20 PWM fake MPPT controller?

In a previous post You said your 4 panels were
150watt
Voltage 17.6v
Current 9.12a
Open current voltage 21.6v

Do you have grid power?

Isnt 17 volts too high to charge lead acid batteries?

 

[justlikethat]

I'll just wait for my new controller thanks

 

[justlikethat]

It's this one.looks good right?

MPPT SRNE SR-ML 40A, 12/24v - ABC Solar Electronics

MPPT SRNE SR-ML 40A, 12/24v Php 4,500.00

abcsolarelectronics.com

Usd100

 

[sed6]

It's this one.looks good right?

MPPT SRNE SR-ML 40A, 12/24v - ABC Solar Electronics

MPPT SRNE SR-ML 40A, 12/24v Php 4,500.00

abcsolarelectronics.com

Usd100

For Usd100 that looks good. It only accepts 550w of panels at 12v (your 600w will be fine). If you want to grow your system in the future you'll need to switch to a 24v battery system and then that controller can take up to 1100w of panels.

 

[Craig]

I have done it many times without issue. Obviously monitor it as you are charging. And maybe don't do it for too long of a time at once. And just because I have done it does not make it right lol.

 

[Craig]

I think a sla battery could handle 50 amps of charging.

 

[justlikethat]

Thanks so much

 

[Forbisher]

Thanks so much

Do you have access to grid power?
I presume 240 v AC in the Phillipines.
Or do you only have batteries to power your fridge?

 

[Delmar]

I just ran a 3-hour test, babysat the batteries and taking readings every 10 minutes:
https://diysolarforum.com/threads/g...st-with-four-hqst-12v-100w-solar-panels.6984/

Edit:

And just because I have done it does not make it right lol.

 

[justlikethat]

I got access to 120

 

[Forbisher]

I got access to 120

OK so charge your batteries with a battery charger. Do you have one?
A battery charger can not be too expensive there.

 

[tictag]

Can I temporary connect the 600w solar panels directly to the battery to charge it?

No. Just don't. Buy a mains charger or replace the SCC.

And it's not the voltage you have to care about initially because connecting directly to your battery will drag the array down to the battery voltage anyway. A lead-acid battery should not generally be charged at higher than C/100A e.g. 10A for a 100AH battery. Whilst your 600W array will not be delivering 600W at your battery voltage it will still likely pump out more than your battery can cope with without damage.

p.s. I charged two 110AH SLA batteries in parallel at 40A (2 x 11A = 22A, or 18A more than they were rated for), had to replace them 6 months after I purchased them, capacity had reduced to maybe 10AH each.

Edit: Added postscript.

 

[justlikethat]

Hi guys, so finally my $200 40 amp solar controller arrived,and guess what? With 600 watt of solar in parallel I should be producing maximum 40 amps. On a non cloudy day they only produce max of 17amp. When the sun is right above them...
Also when I connect the panels individually and count the amps I get 5 more than when I connect them all together. Why is that?
I thought I would get about 30 amps. Battery is still not fully charging,please help!

 

[Forbisher]

Hi guys, so finally my $200 40 amp solar controller arrived,and guess what?
With 600 watt of solar in parallel.

Why are you parallel connecting four 150 watt panels on a 100 volt max input MPPT controller?
You may be below the minimum voltage your MPPT needs to work properly.
Your Vmp is only 17.6 volts with 4 in parallel.

Connect your panels in 2 series for about 35 volts then parallel that for about 18 amps.
2Series2Parallel.

In a previous post You said your 4 panels were
150watt
Voltage 17.6v
Current 9.12a
Open current voltage 21.6v

Also if you are using the same 200amp deep cycle 12v flooded battery then I think it may be at reduced capacity from all the abuse I remember from your previous posts. Running flat, under charging and leaving discharged.
And over charging if you connected all 4 panels directly to your batteries without a charge controller.

 

[justlikethat]

Here are the details of the controller.
Yes using same battery and never connected the panels directly.
What should I do, are you sure I cant connect all in parallel?

 

[justlikethat]

I just feel that the battery is not getting fully charged as it's not getting enough amps during a sunny day and I'm using the fridge.

 

[Forbisher]

What should I do, are you sure I cant connect all in parallel?

Do Not connect 4 panels in parallel on your new MPPT controller.
Your old junk PWM controller could Only be connected in parallel coz it had a 25 volt max limit.
Your MPPT controller needs higher voltage to work properly. 17 volts is too low.
Please try your panels in Series and Parallel.
2 in Series.
other 2 in Series
then Parallel those 2 sets.
Or just keep complaining about how your battery does not get charged fully.