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Charge 12V from 24V battery

Michael S

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Sep 23, 2019
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I know about the battery Isolators, that Will has on his site, but they all seem to be 12V to 12V.
I could use a 24V to 12V converter, to feed the battery isolator. $140 - $200
Or an inverter to a normal 12V battery charger. As low as $50 but inefficient.
Is there a better way?
 
kernel Thanks for finding that. I was looking for something with fewer features.
What would happen of you connected the panel input of a cheap PWM charge controller to the 24V battery?
 
Ot could fry.... just about every manual says not to do it or power inverters and other power supplies.
 
kernel Thanks for finding that. I was looking for something with fewer features.
What would happen of you connected the panel input of a cheap PWM charge controller to the 24V battery?
Id keep shopping around. Look at the whole of offerings at etrailer, rv/marine and other powersports suppliers.

Justin laureltech (?) on here works in the biz.
 
I am not sure what your use case is for charging 12v from 24v battery, but I just started using this BattGO T8 to charge cells and batteries. Very flexible in regards to input voltage, charge current and charge voltage. So far I am pretty impressed. 30A charging is quite nice. Being able to charge individual cells or cells in parallel is great for top/bottom balancing.


The only inconvenience might be that it requires XT-60 connectors for input and output power.
 
I tried a test config (with fuses etc to be safe) with my old PWM 20amp solar charge controller, and the battery voltage went up to 18.6v when I applied power from the 24v battery side to the solar terminals.
I am not understanding what you tried.
If you hooked up solar before battery, i think the scc assume you are charging voltage that your panels produce (rather than 12v).
But not sure what you tried.
 
I cascaded the PWM charge controller off the load connection on the MPPT in 24v mode.
So if you're putting something other than solar into an SCC, you're off script and its beyond my experience what will happen or what should happen.

Good luck! Please post your results, especially if successful or spectacularly unsuccessful with video footage.
 
I have a SLA 55Ah to run a CPAP overnight in case of a power outage. I currently keep it on a wall float charger and disconnect it and move it when I want to use it. I have a controller and 400 watts of solar that can recharge that battery in a couple hours.
I was thinking of getting a 24 volt pack of those Xuba cells to charge from the solar and expand the functionality, but I will need a way to charge smaller batteries, that will be disconnected and moved to where the power is needed.
I also have a couple in the 5Ah range that would be nice to charge also so adjustable charging current would be nice, I am currently changing those with a 15 watt system.
 
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