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diy solar

Runnin hot 14.6ish

Sundog33

Sun Bather
Joined
Feb 1, 2021
Messages
225
Location
Cinnaminson, NJ
So, how to deal with 12v loads when LITHIUM Battery voltage can theoretically go up to 14.6 volts?

I like to use as much straight 12v things as possible, I'm sure lights and Fans would run over 14v,
but most likely be brighter and faster and have shorter life.

I used to use a DROK step down regulator on my old AGM System. But it was only good up to 3 amps.
and I just read that buck converters don't really work in this scenario anyway? Is there a magic bullet for regulated 12v?
I see Will talk about being pleased that some ALL-IN-ONE units have regulated 12v outlets. How to accomplish
that on your own? Really Victron should be regulating the Load voltage from the Charger, but I'm not seeing that.
Unless I just didn't go up high enough yet to notice.

Thanks
 
So, how to deal with 12v loads when LITHIUM Battery voltage can theoretically go up to 14.6 volts?

Same way as FLA/AGM/GEL.

I like to use as much straight 12v things as possible, I'm sure lights and Fans would run over 14v,
but most likely be brighter and faster and have shorter life.

Most components, particularly lights and fans, designed to work on 12V systems are designed with the higher voltages in mind. I personally have some Rolls FLA batteries that charge to 15.0V, and MANY FLA/AGM specify voltages above 14.6V. RV electric systems routinely see 13.8-14.4V most of the time.

I used to use a DROK step down regulator on my old AGM System. But it was only good up to 3 amps.
and I just read that buck converters don't really work in this scenario anyway? Is there a magic bullet for regulated 12v?

There are many DC-DC converters/regulators on Amazon that can give you regulated 12V.

I see Will talk about being pleased that some ALL-IN-ONE units have regulated 12v outlets. How to accomplish
that on your own?

There are many DC-DC converters/regulators on Amazon that can give you regulated 12V.

Really Victron should be regulating the Load voltage from the Charger, but I'm not seeing that.
Unless I just didn't go up high enough yet to notice.

They would be the only one doing this, and that would make them even more expensive. Load ports get battery voltage. Period.
 
Yep, thats what I asking. If there are any electronic engineers on here that have any experience
on what type of regulation is appropriate for this situation. Is it a Buck converter?
Are all step down DC TO DC regulators buck converters?
So much cross talk contamination on line... it would be nice to know someone applying it.

14.6 is a lot higher than any AGM could ever get to and I worried about it then. I had a PC fan fry very
weirdly above 13 on my AGM thats why I looked into it. May have just been a fluke.
But if big battery boxes are doing it. Its probably a god idea I would think.
 
The LiFe pack won't stay at 14.6 very long unless the charger is holding it there .... and then the problem is the system configuration. It will drop back to 13.6 or lower pretty quickly.

By trying to use a regulator of some sort you are loosing efficiency. Sorry, but I think this is much ado about nothing.
 
It was probably current that fried it. Do you know the specs of the fan? I have over volted ebike motors from 36v to 72 volts.
..... or a bearing went out of it and caused the over current.
 
Maybe, I kinda agree with all of you. And I noticed at 86% charge I’m still only sitting at 13.3 now that the suns gone down here.

it was just a pc fan that I savaged to give some air movement in the garage and the leads to the fan burnt up in a big mess. Probably just ceased.

but the question remains : Why is Will so happy when there is a regulated 12v output? And why would they add extra cost if it was inconsequential?

I will most likely do nothing and see how it goes.
 
Btw. That’s what the thread was saying.
that a buck converter is really useless because it only regulated the volts not the amps.
 
Maybe, I kinda agree with all of you. And I noticed at 86% charge I’m still only sitting at 13.3 now that the suns gone down here.

it was just a pc fan that I savaged to give some air movement in the garage and the leads to the fan burnt up in a big mess. Probably just ceased.

but the question remains : Why is Will so happy when there is a regulated 12v output? And why would they add extra cost if it was inconsequential?

I will most likely do nothing and see how it goes.
Well, it also depends on the load requirement, Some load may run happily between 10V ~ 15V so no regulation needed, some may not like it. So look at the spec of the load you have.
 
Btw. That’s what the thread was saying.
that a buck converter is really useless because it only regulated the volts not the amps.

One generally does not need to regulate the amps. The loads determine the amps needed. The converter just regulates voltage UP TO a maximum amperage.

For example, let's say you have a 12V USB charger that can charge a phone at 10W. This will pull 10W/12V = .83A. The converter does not need to limit the current to 0.83A. The load only pulls 0.83A when offered a 12V power source. If the 12V power source has a maximum current > 0.83A, all is well. If it can only deliver 0.5A, it will shut down.
 
That makes sense. I’m not sure what the issue is.
that regulator you linked me says right in the description not to be used with charge controllers...

again it seems like Victron should do this. What exactly is a Solar Charge Controller??
It is a regulator! It takes 20v+ of PV power and turns it into something your battery can handle. Why can’t it then clean up the power more for Load?

i am disappointed that in the 10 years that have passed since I built my AGM system there is still very little exceptional DYI equipment. And will never be. The manufacturer's will make all in one units that will flood the market.
 
why charge to 14.6 volts anyways. 13.8v is over 99% and much easier on your batteries
 
why charge to 14.6 volts anyways. 13.8v is over 99% and much easier on your batteries

Speed of charge. Charging to full @ 13.8V can take 50%-200% longer depending on charge current.

That makes sense. I’m not sure what the issue is.
that regulator you linked me says right in the description not to be used with charge controllers...

There is no issue with hooking the regulator to the charge controller in the manner we've discussed. For each component they list, there is a way you do not want to hook this unit to them.

again it seems like Victron should do this. What exactly is a Solar Charge Controller??

A solar charge controller is a device that accepts PV input and charges a battery. My $900 Victron 250/100 doesn't even have load ports. In fact most Victron models don't.

It is a regulator! It takes 20v+ of PV power and turns it into something your battery can handle. Why can’t it then clean up the power more for Load?

You're still describing two completely different functions.

Because that's not what load ports do. I'm sorry you don't like the way the industry has been doing things for decades, but if there was a legitimate demand for what you want, it would have been met. 12V devices that are typically connected to 12V batteries are designed to handle the higher voltage, and the reality is they are only subjected to the highest voltage for brief periods during bulk and absorption charging. During the majority of operating time, they see 13.8V max during float and under 13V while solar charging isn't available.


i am disappointed that in the 10 years that have passed since I built my AGM system there is still very little exceptional DYI equipment. And will never be. The manufacturer's will make all in one units that will flood the market.

You're mostly alone in this. The market has expanded substantially with many more options available.
 
that in the 10 years that have passed since I built my AGM system there is still very little exceptional DYI equipment. And will never be. The manufacturer's will make all in one units that will flood the market.
I have a complex DIY system using an All In One inverter. The biggest risk to my DIY projects is NEC 2020 which makes my DIY battery pack difficult to get approved in the future. Other than that I can still DIY sub panels, HPWHs, inverters etc.
 
Not trying to pile on here, but would like to point out a big advantage to DIY'ing all your external regulators and whatnot compared to an all-in-one:

Have you seen the scenario where somebody overloads the usb-port on the all in one, it fries and takes out the main motherboard logic to the whole box? I have. Pretty sad if someone is using that as their life-saving "goto" box.

For the same reason, wherever I see usb-ports included on solar-controllers, I simply avoid using them. Just in case it is wired such that a fried usb port takes out the whole controller.

If something smokes on my system, at least the sub-system parts won't take out all the rest! :)
 
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