My 24v 24kw Blueprint

[GLC]

I don’t have a 12volt battery charger. Is there other ways or i need to order one?

Yes, kind of a redneck way. Do you have a car with booster cables? Still disconnect each battery. One at a time with your lowest voltage battery first, connect your jumper cables to you car battery and then to your battery. DO NOT CROSS WIRE YOUR CONNECTION AND DESTROY YOUR BATTLEBORN, POSITIVE TO POSITIVE, NEGATIVE TO NEGATIVE MAKE SURE. Charge just enough to get each battery to 11 - 12 volts. Then reconnect to solar setup. Just FYI, do not rest your batteries on the concrete floor. Piece of wood, carpet, mat will work. We will still need to upper balance them once the batteries start charging from the controller but for now lets just get them firing the controller. Closer volt readingon each one the better when you are charging them on your car.

 

[yambine]

Your cars alternater would work, in a pinch.

I think I’m gonna just order one on Amazon. Anything i need to watch out when charging them? What will be optimum voltage level? I will get back to you once balanced

 

[timselectric]

14.4 volts is full charge, for a lifpo4 12v battery.

 

[GLC]

Your car will work, trust me, I have done it on mine once. No need to wait for a charger. You want just enough voltage to fire the controller. It will not take much. If you are looking for something in a 12 volt charger just to fire the system any small trickle charger will work. If you are wanting to by a charger for the future, call battleborn for recommendations on a 24 volt charger. Just not to shock you, they are pricy.

There is one more way that will fire your setup instantly. Rewire your batteries to 4P, disconnect your inverter. Now your setup is 12 volts. Just for a second, connect your booster cables to your car, it will read 12 volts on your controller and the controller will start charging at 12 volts. Once batteries are slightly charged IE 11- 12 volts, kill your system again and reconfigure to 24 volts and re-check all of your wiring. Connect batteries to controller and fire it. Controller will now read 24 volts now and continue charging.

 

[GLC]

Just FYI, your controller will work on 12 or 24 volts. No setting needed, It does this automatically when it senses voltage. Just connect the wires.

 

[yambine]

Your car will work, trust me, I have done it on mine once. No need to wait for a charger. You want just enough voltage to fire the controller. It will not take much. If you are looking for something in a 12 volt charger just to fire the system any small trickle charger will work. If you are wanting to by a charger for the future, call battleborn for recommendations on a 24 volt charger. Just not to shock you, they are pricy.

There is one more way that will fire your setup instantly. Rewire your batteries to 4P, disconnect your inverter. Now your setup is 12 volts. Just for a second, connect your booster cables to your car, it will read 12 volts on your controller and the controller will start charging at 12 volts. Once batteries are slightly charged IE 11- 12 volts, kill your system again and reconfigure to 24 volts and re-check all of your wiring. Connect batteries to controller and fire it. Controller will now read 24 volts now and continue charging.

Wait i thought i need to charge all of them and balance them to 14.4v or am i just trying to jump start the controller? My friend has a 12v charger i will swing by when I’m heading home. If just to jump start do i just keep the current 2p2s wiring going and connect the 12v charger clamps to the positive and negative battery terminals?

 

[yambine]

Yes, kind of a redneck way. Do you have a car with booster cables? Still disconnect each battery. One at a time with your lowest voltage battery first, connect your jumper cables to you car battery and then to your battery. DO NOT CROSS WIRE YOUR CONNECTION AND DESTROY YOUR BATTLEBORN, POSITIVE TO POSITIVE, NEGATIVE TO NEGATIVE MAKE SURE. Charge just enough to get each battery to 11 - 12 volts. Then reconnect to solar setup. Just FYI, do not rest your batteries on the concrete floor. Piece of wood, carpet, mat will work. We will still need to upper balance them once the batteries start charging from the controller but for now lets just get them firing the controller. Closer volt readingon each one the better when you are charging them on your car.

Sorry i guess i missed this post. I have attached the jump start diagram. Let me know if you see any issues I don’t wanna destroy my batteries. Also I remember two of four batteries are above 11vol, should i still charge them?

 

[GLC]

Wait i thought i need to charge all of them and balance them to 14.4v or am i just trying to jump start the controller? My friend has a 12v charger i will swing by when I’m heading home. If just to jump start do i just keep the current 2p2s wiring going and connect the 12v charger clamps to the positive and negative battery terminals?

First things first. You have two options. 1. Buy a charger, disconnect all batteries from system, charge all batteries to full state of charge individually at 12 volts and then hook them to your system verify that they are all top balanced equally and go from there. 2. Jump starting your solar controller to charge your batteries at 24 volts instead of charging individually at 12 volts. You will still need to top balance your batteries because they are starting out at different voltages and will all move together up and down. This way just you are using the panels to charge your batteries vs charger.

As far as hooking up your friends battery charger while your setup is still wired at 24 volts. This is what you do, you will connect your battery charger to an individual battery starting with the lowest voltage first. Remember if your do not disconnect wires to batteries/inverter, you still need to be charging each battery as an individual not as a group. You do not hook up your charger to the + and - wires going to your inverter. Those wires are wired 2P/2S and are 24 volts not 12.

Remember, your goal is to get your controller working again whether you are using your panels or a charger to get enough volts to start your controller.

As batteries get close to being topped off, you will need to top balance. You can do it two ways. Individually charge batteries with a charger to bring a particular low voltage battery up to match the others in a higher state of voltage or attach a device to pull volts out of your higher charge batteries to get closer to your lower charge batteries. You may need to do this a couple of times until all batteries are within .1 or .2 volts when batteries are at the top register of the charging cycle.

 

[GLC]

Sorry i guess i missed this post. I have attached the jump start diagram. Let me know if you see any issues I don’t wanna destroy my batteries. Also I remember two of four batteries are above 11vol, should i still charge them?

Your drawing is correct to jump / charge batteries. Although, you have the car/ battery and the charger being used. You can do one or the other meaning using the car battery or the charger not both at a time. Is the battery still in the car or are you taking it out of the car? If using your car, you would take the individual battleborn batteries out to your car one by one and charge with your car running with booster cables.

Also I remember two of four batteries are above 11vol, should i still charge them?

See my previous post.

 

[HRTKD]

All four batteries should be at the same state of charge before reconnecting them. This is especially important for the batteries in series because if you have one at 95% and the other at 60%, once the first battery's BMS sees 100% it could trip the over voltage protection, which would then prevent the second battery from getting fully charged.

 

[yambine]

Your drawing is correct to jump / charge batteries. Although, you have the car/ battery and the charger being used. You can do one or the other meaning using the car battery or the charger not both at a time. Is the battery still in the car or are you taking it out of the car? If using your car, you would take the individual battleborn batteries out to your car one by one and charge with your car running with booster cables.

Also I remember two of four batteries are above 11vol, should i still charge them?

See my previous post.

Ok I’m just going to do it like in these photo without the car battery. Btw I just measured voltages for all batteries again they are 10.64, 11.44, 11.50 and 12.63. So I’m gonna charge the first 3 individually to around 12.62-12.64 then fire the 2s2p up again. Let me know if you see any issues. Thanks!!

 

[HRTKD]

Voltage isn't an accurate measure of state of charge for LiFePO4 batteries. If you actively monitor the amps, once they fall off (less than .5 amps?) then the battery is likely charged. But that old school battery charger doesn't have many amps in the maintain mode. Boost is closer. But a good quality charger that understand the LiFePO4 charge profile is best.

 

[yambine]

Voltage isn't an accurate measure of state of charge for LiFePO4 batteries. If you actively monitor the amps, once they fall off (less than .5 amps?) then the battery is likely charged. But that old school battery charger doesn't have many amps in the maintain mode. Boost is closer. But a good quality charger that understand the LiFePO4 charge profile is best.

Are you sure “boost” mode is safe? The maintenance mode is taking forever

 

[HRTKD]

Are you sure “boost” mode is safe? The maintenance mode is taking forever

No, I wouldn't say safe. But it's closer to the number of amps you want to use. 2 amps is going to take for ever. 10 amps will take less time.

I see the potential for a less than optimal charge here. The BMS will protect the battery, so you could switch to the 10 amp charge and assume that the BMS will keep anything bad from happening. If you go that route, keep any eye on the voltage.

Battleborn has put in their BMS as a firewall to keep people from doing bad things to the battery. I wouldn't rely on that 24/7, but in this case for a short term charge, it may be acceptable.

Optimal is to use a charger that understands how to properly charge a LiFePO4 battery.

 

[GLC]

Ok I’m just going to do it like in these photo without the car battery. Btw I just measured voltages for all batteries again they are 10.64, 11.44, 11.50 and 12.63. So I’m gonna charge the first 3 individually to around 12.62-12.64 then fire the 2s2p up again. Let me know if you see any issues. Thanks!!

Yes, it looks good. All you need to do is a slow charge to get your volts up. Like i said, try to get them as close as possible the same volts. At least all around 12. Then hook them back in the 2s/2p. Controller will fire back up. Or if you want do a slow charge till around 13.7 where they will basically go into a float charge voltage. You call either way will work fine. Slow charge is the way to go.

 

[yambine]

Yes, it looks good. All you need to do is a slow charge to get your volts up. Like i said, try to get them as close as possible the same volts. At least all around 12. Then hook them back in the 2s/2p. Controller will fire back up. Or if you want do a slow charge till around 13.7 where they will basically go into a float charge voltage. You call either way will work fine. Slow charge is the way to go.

The system is fired up! All four batteries started around 12.70v. Since today is overcast the panels are charging very slowly. After about an hour, the voltages for four batteries are 12.97, 12.94, 12.94 and 12.92. So how do I proceed? Thanks.

 

[GLC]

Looks good, let them charge out and go to float without using any power. Keep an eye as they top out. Verifying that they go up within .1 or .2 volts of each other. If they do, you are good to go. Unless the battleborns were bought at different stages of your build, they should top balance pretty much the same. If for some reason they do not, its not the end of the world. We will just need to top balance them. I listed the steps in a couple of posts ago. For now, let it run and see what happens.

 

[yambine]

Looks good, let them charge out and go to float without using any power. Keep an eye as they top out. Verifying that they go up within .1 or .2 volts of each other. If they do, you are good to go. Unless the battleborns were bought at different stages of your build, they should top balance pretty much the same. If for some reason they do not, its not the end of the world. We will just need to top balance them. I listed the steps in a couple of posts ago. For now, let it run and see what happens.

So all voltages are the same which is good news. But why are the voltages dropping? Around 2:50pm each was measured at 13.34 but now 4:15pm they are all 13.31. And yes I’m still charging them with the panels but its overcast again today so its about 50-100w. And is fully charged voltage 14.4?

 

[GLC]

Guessing that you are not pulling power out, correct? Inverter is not on? My batteries settle down after charging to around 13.3 volts or 26.6 volts on 24 volt system. By voltage check, that is around 90 percent. Bear in mind checking voltage reading does not necessarily give full info on what state of charge really is. Lipo4 batteries has a very flat line depletion rate. So even though by volt meter they may appear low, they are actually fully charged. Just fyi, batteries will never stay at 14.4 volts. They will top out and then float back down. Also 50 to 100 watts of charging is not very much at all. At that rate it would take a very long time to see any effect at all.

 

[WYtreasure]

Hi Rmaddy,
I have completed most of the wirings. Can you take a look at the attached configuration and let me know if I’m missing anything before I start hooking up the batteries and solar panels? Thanks in advance!

Hey yambine, looks like a pretty nice setup BUT are you putting your crimp ring terminal connectors ON TOP of washers?

Battery Melt Down Narrowly Averted - Marine How To

Note The Melting of The Battery Case (originally published July 2012) The connections to your batteries matter. How you make them, how you torque them and how clean they are all matter. Not following best practices or marine wiring standards can impact your personal

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