Easy Desktop Charging A123 4S2P LiFePO4 

A viewer asked if I could do a short explainer video showing desktop charging of our latest battery pack. Of course I can!
So far I’ve tested two different ways to do it. this is my preferred method on the desktop using readily available tools.
In this video I use a constant current constant voltage Buck converter, fed by an HP laptop power supply. The constant current constant voltage Buck converter feeds the Genasun on solar charge controller. The solar charge controller charges and maintains the battery pack, and also outputs a nice voltage to its load port.

Why use the Genasun Charge controller?
In the example shown in the video, the charge controller is in the loop because we are replacing the Sun as the primary means of powering up our system, with an adjustable CCCV buck. It’s important to understand that the battery, the BMS, the charge controller, and of course our DC power source, are all puzzle pieces of a solar generator albeit, quite a small one.

Can we do the same thing without the charge controller?
Absolutely! The BMS is going to manage the high and low voltage while charging from a CCCV buck. All we have to do is set up the buck converter at the correct voltage and amperage for the battery we’d like to charge. If you’ve used the correct BMS, the BMS will disconnect the buck before any cell damage will occur from overcharge. Just do me a favor guys and don’t leave these batteries unattended while charging.

Constant Current Constant Voltage regulator
Constant current constant voltage regulator in the video allows you to adjust voltage and current. This is critical because we want to charge hour packs as gently as possible. I never give more than one amp for a 10Ah hour pack. It doesn’t mean you can’t give more, but the more gently you charge the more Cycles or charge cycles you’re going to get out of the pack.
You can purchase the cccv adjustable voltage and current regulator from eBay.

What about a solar gen project on the channel some time?
Absolutely, and its already in the works.

 I did make one mistake in the video, that is I said limiting the charge voltage will extend the life of the battery. That’s true, but that’s definitely not what I meant to say! I meant to say limiting the charge current will extend the life and health of your battery packs. That’s why we’re using this constant current constant voltage buvk converter, to limit the amount of current going into the battery.


The short explainer videos are kind of a test at the moment. I definitely wouldn’t make them my primary content, but I do like them as a way to augment the larger more detailed videos put out each month nearly once week/month.

73
Julian oh8stn

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