Charging a 24v off grid system with a 12v battery bank!

Now it's time to put the crazy 12v battery bank to good use! I'm going to connect a 12v inverter and then plug in a 24v charger to see if I can charge up my 24v system! I will also be measuring the losses from the DC to AC to DC conversion.

--=Items in this video:=--

Haisito 20 Amp Lithium Battery Charger, 12V and 24V Lifepo4,Lead-Acid(AGM/Gel/SLA..) Battery Charger ,Battery Maintainer, Trickle Charger, and Battery Desulfator for Car ,Boat,Motorcycle, Lawn Mower

UNOWIX LiFePO4 Deep Cycle Lithium Battery
Official UNOWIX website:

Ampere Time 12V 50Ah Lithium LiFePO4 Battery, Ideal Replacement for 12V 100Ah AGM SLA Battery

SFK-275HP 12V 275AH HIGH POWER LITHIUM IRON PHOSPHATE BATTERY
Use coupon Code "OGB" at checkout and get the Heated Battery Bag for Free! This is only for the 275ah battery. Also, Free Shipping on this Prebuilt Battery!

12-Way Fuse Block, Waterproof Boat Fuse Panel 12-24V Marine Fuse Block with LED Warning Indicator Damp-Proof Cover - 12 Circuits with Negative Bus Fuse 12V Box for Vehicle Car Boat Auto

BNTECHGO 12 Gauge Silicone Wire 10 ft red and 10 ft Black Flexible 12 AWG Stranded Copper Wire

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#12vbattery #parallelconnection #lifepo4

[Sylvan_dB]

It would be good to get rid of the inverter losses. The best is a DC 12v to DC 24v charger (DC to DC charger). I think Victron makes one. Maybe Renogy also?
Another way that might work would be to make your own with a DC:DC boost converter and solar charge controller. Boost the 12v to a high enough level (40v and up depending on the controller) to feed the input of the solar charge controller. Most MPPT charge controllers will work with that. It should be fairly easy to get 500 to 600 watts that way (do not connect the boost and the solar panels at the same time to the same controller) and reduce the losses considerably because operating in a more efficient range than the inverter plus charger together. But what you have works!

[rickharold]

Cool experiment. I’ve tested various inverters and they have 9-18% loss. So for my off grid systems I usually try to go direct to DC from the battery where possible.

[zabarpakistanofficialchann]

Sir 💙💙lot of respect from Pakistan . its very good video . I was hungry for this for a long time. Thankyou .

[KOMV]

I plan to use this setup to charge a battery using a portable solar panels when the sun ☀️ area is too far from my trailer and then transfer it later to the trailer’s battery bank with this setup.
Thanks for your channel, I learned and picked up lots of ideas from the videos you’ve done…keep on testing 😊👍

[IamMotorHomeless]

OK... but now that you have the Gold battery. have you considered connecting the two 100ah and the 50ah in parallel to make a 250ah pack and then connect that in series with the 275ah battery.
It would only run as a 250Ah 24V battery. but you could then just use a 24V DC to DC charger and have much less losses.

[chrisreynolds]

I would imagine to get the best efficiency, put 3 similar batteries in series to get 38.4 nominal and feed it into the charge controller in place of the solar panels and let the MPPT deal with it.

[timlochner]

To bad the batteries weren't the same so u could series them . And use a victron dc to dc charger I wonder if that would be mote efficient . Just was curious about your growatt install is going ? If your interested In grid tie with limiters at all. I could send u some pics of my system.

[CanadianTank]

Victron makes a good DC-dc charger. And there are a few other DC-DC chargers if you want to save a buck

[hustlazk]

good video and experiment there. theres too many process to get to the 24v system... inverter... charger...fuses... (replace fuses with circuit breaker) and the wiring is quite long too. shorter is better...the killawatt meter contribute a loss too... the better way is dc-dc converter. it reduce most of the process. there were cheaper on ali or amazon.

[opless]

You’ll get more efficiency from a DC-DC converter. Though I don’t know of any that do 12-24v!

[farside]

Not sure why you wouldn't just series connect a couple 12v batteries to make a 24v battery, and add that to your 24v system. It sounds to me that it would be more efficient that running your 12v batteries through an inverter. You already proved the inverter is a power drain, remove it from the equation.

[istvanhideg]

How about using a DC-DC buck converter?

[matthewknight]

I watch a lot of your videos. Im needing advice on how i could use my 24 volt nissan leaf battery ive built alongside my 24 volt lifepo4 14 kw battery i built from 280 grade a eve cells. My 16 eve cells are actually 29.2 volts max and my leaf battery is 25.1 volts max. Id like a way to use both. Ive spent so much money on building both batteries and i hate to see my leaf batteries just sitting here not being used. Its 24 modules 6s8p while my lifepo4 is 2p8s

[petertomas]

Great video once more ! I would like to ask about opinions on something that came up to my mind yesterday allthou its not relevant with the subject of this video but i think its important. We all know that we should never give power from solar panels to the Mppt charger before we first connect the output of the charger to the battery for two main reasons. First the charger needs to detect in what voltage our battery bank works and second charger may be damaged. So here is the scenario. Its a nice bright sunny day and the charger is charging the batteries at full power and for some reason suddenly....poof...the fuse on the positive cable of the charger's output blows off, or the breaker pops off (whatever we have). In that case the charger is not connected to the battery anymore but the input power from the solar panels is still connected. Isn't the charger in risk to get damaged ? Im very interested on hearing your opinions.

[sophiafunworldatthepark]

Hello, I recently bought a 110 watt 12v solar panel and I have a 24v 100ah battery. Can I charge my battery with that solar panel? Base on my calculator, It will take 3.32 days to fully charge it. 2560 watt battery (25.6vx100ah) and 2560watt/110watt is 23.27 charge time, assume peak 7 hours each day. Thus, I need about (23.27 charge time/7 hours) 3.32 days to fully charge.

[vinniec]

I don't understand why the 500 watt inverter did not work. Did you try it again later? I am wondering if there was a loose wire or plug.

[jasonbroom]

I was really hoping you were going to show the losses from multiple inversions, then show running a boost converter to take your 12v DC source and bring it up to around 28 volts, which you run into the "solar" input on your system. Instead of a 28% loss, you'd probably be around 10%.

[jay.powerstroke]

Some batteries say no more than 4 in parallel and not safe to do more. Why is this? Yet I see many people do more than 4. Long as I make sure once and awhile that they are at equal soc should it not be ok? Just got 4 12v batteries and would like to add a 5th. All connected to victron power in buss bar with equal length cables and fused separately. Cant see why this would be unsafe

[harryspence]

Why not wire two 12vdc battery's in series for 24vdc. Then use 24vdc group's in parallel? No conversions.

[hanshonstatzky]

Why would you connect the batteries to a fuse box not just in parallel. That's is from one positive to the next positive and so on.