Parallel charging

OMG

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I have very limited solar experience. I am trying to understand the gain from parallel charging. If anyone can explain the gain in layman’s term I will be ever grateful
 

sunshine_eggo

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Rednecktek

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In short it allows you to use different size arrays. If you built a system from scratch matching everything then it's not an issue.

However, if you started out with a half dozen 100w panels and then got an odd number of 300w panels and then bought some 435w panels... well getting them to parallel or series together will nerf the hell out of your system.

So, if you put the 100w panels together on one controller, and put the 300w panels on another controller, and a set of 435w panels on their own controller, then each controller can maximize its output on its own without nerfing the other setups.

The other reason to parallel controllers is because 2 40a controllers might be cheaper than a single 80a or redundancy if 1 controller/set dies you're still creating power.
 

OMG

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Thank you for replying. In Wills book (the off grid king) set up calls for a 80 amp controller or 2 40 amp controllers but it stops there. So the only thing I could figure was to parallel them. But with my limited knowledge I am having trouble grasping the gains from charging this way. 12 volts 10 amps paralleled with 12 volts 10 amps is only 12 volts 10 amps. sorry but electrical engineering escapes me
 

cs1234

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Thank you for replying. In Wills book (the off grid king) set up calls for a 80 amp controller or 2 40 amp controllers but it stops there. So the only thing I could figure was to parallel them. But with my limited knowledge I am having trouble grasping the gains from charging this way. 12 volts 10 amps paralleled with 12 volts 10 amps is only 12 volts 10 amps. sorry but electrical engineering escapes me
12 volts 10 amps (120 watts) paralleled with 12 volts 10 amps (120 watts) is 12 volts 20 amps (240 watts).

Series adds the volts, parallel adds the amps.
 
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OMG

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12 volts 10 amps (120 watts) paralleled with 12 volts 10 amps (120 watts) is 12 volts 20 amps (240 watts).

Series adds the volts, parallel adds the amps.
Yes I forgot that would double in parallel and there is my gain in charging. Thank you for that. Greatly appreciated!
 

cs1234

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Big ones are probably sold less.. and the small ones have to compete with more competitors than the big ones.
 

Handyman mark

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I have a 24 volt system. Two batteries. Can I run two separate 12 volt charger maintainers? When I'm on the grid
 

cs1234

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I have a 24 volt system. Two batteries. Can I run two separate 12 volt charger maintainers? When I'm on the grid

From what I have gathered here on the forums, yes.

If you have two 12v batteries in series at 24v then you should be able to connect a separate 12v charger to each of the 12v batteries positive and negative terminals, provided the chargers are isolated. It's similar to running an active battery balancer. You have to be careful to not provide more amperage than the batteries can support for charging though, if they are still connected to a 24v charger that is running, like your solar.

Also, nobody here will recommend it.. for whatever reason. :)
 

cs1234

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No, it doesn't work that way unfortunately.
I've been trying to make sure I understood this correctly, and just had a discussion in another thread with a couple other forum members. Look at this post and the two posts above it. I'm guessing my stupid is showing again? :(

How is running a separate 12v charger on each of the 12v batteries (of a 24v series setup) fundamentally different than building your own battery pack with paralleled cells internally on each of the BMS connections? I don't understand, I am confused.
 
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