Many devices have built in charge controllers that stop charging when battery is at 100%. I read several places that you can charge devices with the manufacturers recommended voltage and that higher amperage sources will not hurt as the device will take what it needs. True?
Given this, why do portable lithium battery packs (for example a 240WH Lithium pack I know charges at around 40Watts) recommend charging sources be of a limited Wattage? For example if the battery pack has a 12v 3a charge port, any reason I can't plug in a 12v 19a source? Same question regarding a 12v 3a fan, any reason I can't plug in a 12v 9a source?
UPDATE: Part of the reason why I am asking is that I am trying to find a way to charge a 240 WH Lithium power pack with a 200w 18v 11a (max/ideal) solar panel without using another battery. I thought If I just stepped down 18v to 12v with a dc-dc regulator that would be good enough. The manufacture just keeps saying, no more than 100w solar panel.
I guess I need clarity on these NOOB questions:
**(1) Why does the amperage of the power source matter if batteries have a high amperage capacity (2) How do charge cables limit amperage and can this be directly implemented from a solar panel? (3) is there difference in the way battery sources and solar panel sources make available or push power?
I know this is not a typical solar setup.. i'm just looking to leverage a big panel during solar hours without a battery bank These are the products:
My Solar panel is 200w 18v 11a. CHAFON 200Wh Portable Generator Power Station Rechargeable (but want to consider other like Jackery 240). MaxxAir 4401K 4 speed 12v 4a fan. Alpicool C15 12/24v 50watt Freezer. Nextrox DC/DC Converter Regulator 24V Step Down To 12V 20A
Trying to find a way to run and charge these ONLY during solar hours directly (without tying my battery and trusting Low Voltage Disconnects). The freezer supports 12v and 24v. One person at Chafon said no more than 22v, another said no more than 100w input.
I read the duplicate question/answers and it only seems to confirm my suspicion that more amperage availble in the source should not hurt my devices.. but I am still puzzled why manufactures state a limit the input wattage? I understand the Just do what the manufactures says to do and that would be safe I guess but also really complicates the solar panel setup.
**UPDATE: Thank you for comments. somebody on another forum confirmed the Chafon 200wh BATTERY PACK could charge directly from a 12v battery which of course has a lot more watts than the recommended unless fused . For my own understanding and to rephrase the question, what's the difference between power from a 12v battery vs power from a 200 watt (18v 11a) solar panel that has been reduced to 12v. Is the issue that a solar panel is pushing/forcing power where as a battery is offering stable/waiting power ? And how does this apply to a 12v device wanting to charge at 40watts vs a fan that operates at 40watts **