Shunts/dumping excess load

[somawheels]

Example: If i have a 10 amp charge controller, and My PV will output up to 20 amps, What component do I need to get rid of the excess current when it reaches >10 amps?
I have had a search for shunts, but found nothing that makes sense to me
Thanks

[sensij]

You need an mppt CC with current limiting. I would check the ratings of your current cc (model number) against the size of your array... it sounds like there might be a mismatch.

[MetricAmerica]

Buy another 10 amp charger and battery, done... or twenty amp charger...you solar slut you...

[somawheels]

So is there not an alternative method that does not involve buying new charge controllers? If you can get a charge controller with a current limiting device, is there not a standalone current limiting device out there?

[SunEagle]

So is there not an alternative method that does not involve buying new charge controllers? If you can get a charge controller with a current limiting device, is there not a standalone current limiting device out there?

A new 20 amp CC may end up being cheaper as well as help generate more power for you.

[somawheels]

Cheaper than what?
My 10/20 amp story was just an example... Sorry, I should have used a reallife situation for this question
I have a 50amp solar charger built into my inverter, I would like to connect an 70amp PV array. I chose this inverter because it has certain desirable features, however the 50A Charge controller was not one of them.

[sensij]

Please tell us about your 70 A array (panel model? how are they wired?) and the 50 A cc you bought (what model?)

[Logan5]

you would use a resistor or a carbon pile. you could also use a pump, it's called a load dump, most commonly used with hydro and wind. Not usually done with solar set ups.

[sensij]

These ideas are appropriate when using voltage as a trigger to shunt to the load. OP wants to divide current. Creating a load is easy, figuring out when and how much to dump to it is hard. You wouldn't build a passive divider in this scenario, because most of the time, the array won't be producing amps in excess of the charge controller rating. Better to just get a CC that is rated to handle the desired input, or one that has the ability to regulate its output current to stay within its rating.

[somawheels]

I would have 24V panels wired in parallel, each panel outputs 8.46 amps (max). I would only be able to use 6 of these panels with the 50A charge controller.
The model isn't really relevant as it is a cheap thing you wont have heard of, but I can assure you (by looking at the user manual) 6 of these panels is the max.
Thanks

[sensij]

I would have 24V panels wired in parallel, each panel outputs 8.46 amps (max). I would only be able to use 6 of these panels with the 50A charge controller.
The model isn't really relevant as it is a cheap thing you wont have heard of, but I can assure you (by looking at the user manual) 6 of these panels is the max.
Thanks

Why would you use a PWM controller for an array this big?

[Logan5]

I would have 24V panels wired in parallel, each panel outputs 8.46 amps (max). I would only be able to use 6 of these panels with the 50A charge controller.
The model isn't really relevant as it is a cheap thing you wont have heard of, but I can assure you (by looking at the user manual) 6 of these panels is the max.
Thanks

sounds like junk, why would you risk damaging heavy, expensive batteries with a junk controller?

[somawheels]

Because I trust a relatively cheap PWM charger more than A relatively cheap MPPT controller (where there is more to go wrong with the quality of the product)

Well thank you people, I think you given the answer

you would use a resistor or a carbon pile. you could also use a pump, it's called a load dump, most commonly used with hydro and wind. Not usually done with solar set ups.

"These ideas are appropriate when using voltage as a trigger to shunt to the load. OP wants to divide current. Creating a load is easy, figuring out when and how much to dump to it is hard. You wouldn't build a passive divider in this scenario, because most of the time, the array won't be producing amps in excess of the charge controller rating. Better to just get a CC that is rated to handle the desired input, or one that has the ability to regulate its output current to stay within its rating."

I Will just have to stick to 6 panels.

[sensij]

The amount you are saving in the difference in cost between those controllers (or failure risk, or however you want to quantify it) will be eaten up quickly by the lower production of the PWM controller. 6 panels on the MPPT should perform comparably to the same as 8 on the PWM. Pennywise, pound foolish.

[somawheels]

I understand that investing in trustworthy gear is a saving in the long term, but some people simply cant afford expensive gear by trustworthy brands. If you could only buy cheap (but not cheapest) chinese charge controllers, would you get an MPPT or a PWM?

[Logan5]

poor excuse, you have batteries that cost more to replace than a good quality MPPT charge controller. If you can not afford a quality CC, you can not afford to solar charge the batteries, expect to be hauling those batteries back very soon.

[sensij]

First I would figure out how much charge current is needed to maintain the batteries. Not maintaining them properly would be the most expensive choice. Once I knew the charge current required, I'd look at the cost of the panels + PWM controller capable of delivering that current, and the cost of the panels + MPPT to get the same capability, and decide from there.