Xuba has to be making a killing, just on orders from forum members.
Have fun with the cells.
Have fun with the cells.
600w solar, DIY 280ah 24v LIFEPO4 build thread for travel trailer.
- Thread starter Jusbechillin
- Start date
Jusbechillin
New Member
Here we go, top balancing the cells now. They all came in at 3.3v but I put them in parallel for 24 hours for good measure. Now I’m charging them up to 3.65, will let them sit an hour and then check to see if they stayed at 3.6 or not.
This weekend I plan on making a lot of progress on the system!
This weekend I plan on making a lot of progress on the system!
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Jusbechillin
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Actually I bought mine from ShenzhenLuyuanTechnologyCo
Jusbechillin
New Member
It sure does take a long time to get the cells from the 3.32 they started at up to the 3.6 for top balancing. I’ve been at it for about 12 hours and I’ve only moved up to 3.36. I had the power supply set at constant voltage of 3.45 which was only supplying 5 watts at 1.5 amps. Now I have it turned up to 3.6 and it jumps to 13 watts at 3.7 amps.
I wasn’t confident leaving the battery charging at the higher rate over night while I was sleeping. I don’t want to risk the over voltage protection on the $100 power supply I bought failing and overcharging the batteries. So, I’ll keep it at the higher rate only while I can be close by to keep checking the voltage of the cells. This part is the pits. I want to get this hooked up!
I wasn’t confident leaving the battery charging at the higher rate over night while I was sleeping. I don’t want to risk the over voltage protection on the $100 power supply I bought failing and overcharging the batteries. So, I’ll keep it at the higher rate only while I can be close by to keep checking the voltage of the cells. This part is the pits. I want to get this hooked up!
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I didn't leave it alone overnight either. Trust but verify. Can't do that in my sleep. 
My voltmeter goes to three decimal places. Is it really that accurate? Maybe. It did help to see that though.
My voltmeter goes to three decimal places. Is it really that accurate? Maybe. It did help to see that though.
Jusbechillin
New Member
Jusbechillin
New Member
Would upgrading my 10amp power supply to this allow time to top balance much faster?
TekPower TP1540E DC Adjustable Switching Power Supply 15V 40A Digital Display https://www.amazon.com/dp/B015QHVJP6/ref=cm_sw_r_cp_api_i_VUcvFbMVA6RSA
TekPower TP1540E DC Adjustable Switching Power Supply 15V 40A Digital Display https://www.amazon.com/dp/B015QHVJP6/ref=cm_sw_r_cp_api_i_VUcvFbMVA6RSA
Tball
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- Joined
- Mar 30, 2020
- Messages
- 140
Trust me, it will get to 3.6 faster than you think. I followed @FilterGuy guide and they charged and top balanced like a champ!
I think Victron specs the installation of their MPPT as being in the vertical position. The "other" vertical position. You don't want it 90°. The fins on the back need to allow heat to go UP the fins.
On the cable between your switch and the circuit breaker, the mounting points are at different heights. If you rotate the lug 180° on the cable you gain about 1/2", which may allow your cable to be level instead of at an angle. If you leave it an angle, there is stress on the stud where the lug is attached.
I left the battery connections until the very end. That way, when I fumbled something, it was no harm, no foul.
You don't want it 90°. The fins on the back need to allow heat to go UP the fins.On the cable between your switch and the circuit breaker, the mounting points are at different heights. If you rotate the lug 180° on the cable you gain about 1/2", which may allow your cable to be level instead of at an angle. If you leave it an angle, there is stress on the stud where the lug is attached.
I left the battery connections until the very end. That way, when I fumbled something, it was no harm, no foul.
Jusbechillin
New Member
For the victron, that’s an easy fix, thanks for Pointing that out!I think Victron specs the installation of their MPPT as being in the vertical position. The "other" vertical position.
On the cable between your switch and the circuit breaker, the mounting points are at different heights. If you rotate the lug 180° on the cable you gain about 1/2", which may allow your cable to be level instead of at an angle. If you leave it an angle, there is stress on the stud where the lug is attached.
I left the battery connections until the very end. That way, when I fumbled something, it was no harm, no foul.
None of the connections are tight at this point, just seeing how everything goes together. And, I won’t connect the solar wires into the victron or connect the batteries until the end.
I’m also going to add heat shrink to the lugs/wires.
I have a double pole circuit breaker upstream of the charge controller. So I connected everything nice and tight. Only when I was really ready did I throw the breaker into the ON position.
One thing to be aware of is that heat shrink adds stiffness to the wire. You won't be able to flex the wire quite as much. If you have plenty of room and plenty of wire, it's not a big deal.
One thing to be aware of is that heat shrink adds stiffness to the wire. You won't be able to flex the wire quite as much. If you have plenty of room and plenty of wire, it's not a big deal.
Jusbechillin
New Member
Jusbechillin
New Member
I’ve made a lot of progress today:
- battery cells charged to 3.65v for top balancing
- Ran 10/3 Romex from shore plug to inverter/charger
- Ran 10/3 romex from the inverter/charger to the RVs power distribution system
- Ran 10awg wires from the distribution blocks to the location where I’m mounting the buck converter
I ran the same gauge wire for my negative that I did for my positive. So both are 2/0.
Jusbechillin
New Member
Making progress!
First of all, I had a bunch of help from a very patient member on the forum. We changed some equipment and came up with a new wiring diagram.
Im on hold for a a few days while I wait for a part or two to show up.
In the meantime, I zip tied and did some wire maintenance, and wired a bit of the system together. I also got the battery all wired up with the BMS, cell checker, and the Victron battery sense. Unfortunately all of the leads barely reach, so the top of the battery is a rats nest. It looks like a diy bomb you might see in a movie...
Tomorrow, the negative bus bar should be here which is one of the things holding me back from finishing the wiring. I bought two fuses bus bars, and then learned that you don’t fuse the negative wires! Well, we all have to start somewhere, at least I’m learning now!
And the best part, my daughter came out and helped me!
First of all, I had a bunch of help from a very patient member on the forum. We changed some equipment and came up with a new wiring diagram.
Im on hold for a a few days while I wait for a part or two to show up.
In the meantime, I zip tied and did some wire maintenance, and wired a bit of the system together. I also got the battery all wired up with the BMS, cell checker, and the Victron battery sense. Unfortunately all of the leads barely reach, so the top of the battery is a rats nest. It looks like a diy bomb you might see in a movie...
Tomorrow, the negative bus bar should be here which is one of the things holding me back from finishing the wiring. I bought two fuses bus bars, and then learned that you don’t fuse the negative wires! Well, we all have to start somewhere, at least I’m learning now!
And the best part, my daughter came out and helped me!
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Jusbechillin
New Member
- Added inline fuses to the solar panels
- Finished all connections including running a chassis ground connecting to the negative bus bar.
- Tested the BMS and the inverter/charger to make sure all of the cutoffs (over voltage and under voltage protection) work as promised
- I decided to leave one lead acid battery on the tongue of the trailer and kept the existing dc system in tact to charge the battery and operate the breakaway system. I omitted the dc buck converter from the setup for now. If the house dc converter is too inefficient, I will but a quality DC 24>12v converter to add to the system by victron. I regret buying the low end buck converter from amazon that I had planned to use
- I added to vents to the bed box for airflow
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Jusbechillin
New Member
I looked at your pictures a couple posts back showing how you ran the PV wires. I managed to get all my wires hidden in the walls. You might be surprised to find out how much dead space there is in the walls. I got lucky and the entire panel in a closet was held on with just screws. That gave me great access to pull the wires down the wall. The area above the refrigerator was wide open and that's where the wires came in from the roof.
SomebodyInGNV
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- Joined
- Jun 3, 2020
- Messages
- 182
How easily can you source the fuses if one blows while you're traveling?
Always buy a spare, no matter how expensive it is. And don't lose it!
