diy solar

diy solar

13 kWh Lishen van build

I noticed the specs on the Victron 3000 Watt too about significantly less capacity with higher temps. Like you, I'm hoping to be able to juggle loads to keep everything going. My biggest loads are a washer/dryer combo, the A/C, and microwave. Would also like to be able to do induction cooking. Obviously something has to give!

If worse comes to worse I'll purchase a 2nd 3000VA Victron inverter, parallel them, and problem solved.

For your DC low battery disconnect, I've been thinking about that (you've obviously thought this through very well) and wondering if perhaps that isn't necessary in my case as the BMS will disconnect the batteries if they got too low. But perhaps not relying on the BMS is best? I'm probably missing something here. Let me know, and thanks again for sharing!
 
For your DC low battery disconnect, I've been thinking about that (you've obviously thought this through very well) and wondering if perhaps that isn't necessary in my case as the BMS will disconnect the batteries if they got too low. But perhaps not relying on the BMS is best? I'm probably missing something here. Let me know, and thanks again for sharing!
Not necessary, but my opinion is that a bms cuttoff is a last line of defense to avoid cell damage. My inverter is smart enough to shut down before voltage is critical and I’d argue that the dc load bank should be smart enough as well. That’s what the batter protect is.

If you let your bms’s disconnect, you have zero dc power. Many solar chargers won’t start charging again until they have power from the battery, so you are stuck without a way to generate dc power with some jumper cables or shore power charger. I also like keeping dc power so the cerbo and smart shunt can alert me that there is an issue and I can see what’s going on. Final nice feature with the battery protect is you’ve got a handy switch via Bluetooth to turn the dc load center on and off.

Again, not required, but serves a purpose
 
Great build....looking forward to how this operates once you get out there!
 
Great build....looking forward to how this operates once you get out there!
Thanks. I definitely have a long way to go, but I'm already enjoying the electrical system and using the van. I'm a pretty serious cyclist and it's already been to a bike race a couple hours away and the AC was nice. I've also been using the van as home base for a couple other local cycling outings and I've been using the AC quite a bit. Some of that is just system testing more than really needing it, but the system is working really well so far. The Orion chargers are now wired in and I can charge from my alternator and solar when driving. I just installed a composting toilet and fridge (somewhat crude temp installs), so I can sleep, eat, and relieve myself. Other than running water, it's fully operational. We have a trip to colorado in August and I'm looking forward to the first big shake-out trip. I'm planning to get more insulation and some partial temp walls/ceiling up before the trip. Part of my plan is to use the van a bit before finalizing my layout and design, hence the temp install of the fridge, toilet, and walls. Pic below of the final system layout with Orions wired in and some of the wiring cleaned up. I decided to flip the Cerbo on it's side because I haven't considered how far some of those connections stick out. I also wired in a voltage converter to the lynx distributer, so now I get a cool green "ok" light for good connections and it will go red on the appropriate circuit if I blow a fuse. It's not really a feature I needed, but it seemed like a waste of good electronics not to enable it and it was only a $5 part.

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Update on battery performance - We completed our trip to Colorado and the van worked great, including the electrical system. We had a cabin for most of the trip, but had several overnight stays in the van in hot and cold weather. Running the AC overnight in Texas was no problem and I also had to run the heat pump for our first night in CO when it got down into the 30's. Other than my cerbo unit locking up once (requiring a reboot), the system worked perfectly. I still have one cell that seems to top off around 3.4v and never goes higher, but the pack performs well and stays balance everywhere else in the range. I'm seeing good charging performance when driving via the Orions + Solar and never had to plug in during the trip. I also did an overnight trip this past weekend for a bike race and ran the AC in very hot weather for 14+ hours and zero issues. So far, the electrical system is doing everything I wanted out of it, couldn't be more pleased with capacity and performance of the DIY batteries.
 
ase let us know how the dual orions go and if you are adding another alternator. My setup is similar but I only have one Orion and 544ah. In the winter with the espar s3 running and several days of no sun the batteries get pretty low. So I have considered adding another orion.
The dual Orion’s are working great off the stock single alternator. No problem pushing 700-800 watts continuous, even when just idling. These things do get really hot though and that appears to be the limitation on them. From startup, they are usually pushing 800+ amps, which is higher than they are rated for. Once they get hot, they seem to throttle down into the mid 700’s, sometimes slightly below their rated output. There is no way to limit the output amps via configuration, so the Orion’s are always going full gas if the batteries aren’t full. The Orion’s get almost too hot to touch, I’ll probably add some fans when I build out my permanent cabinet.
 
The dual Orion’s are working great off the stock single alternator. No problem pushing 700-800 watts continuous, even when just idling. These things do get really hot though and that appears to be the limitation on them. From startup, they are usually pushing 800+ amps, which is higher than they are rated for. Once they get hot, they seem to throttle down into the mid 700’s, sometimes slightly below their rated output. There is no way to limit the output amps via configuration, so the Orion’s are always going full gas if the batteries aren’t full. The Orion’s get almost too hot to touch, I’ll probably add some fans when I build out my permanent cabinet.
Awesome DIY battery build. Did you check you alternator Temperature after using dual orion charging especially on idle?
I build 560ah 24v 8S2P using similar 280ah battery for sprinter with 220amp alternator and 680w solar when driving or 1100w total possible when parking in right location when I can use 2 extra panes that are slide out . I am also planning to use 2 orion dc to dc.. Do you think it would be better to enable one orion at the time ? and using 2 orions while driving highway?
Thank you you mansion about how hot they get .I will design it with a fan in mind.
 
Awesome DIY battery build. Did you check you alternator Temperature after using dual orion charging especially on idle?
I build 560ah 24v 8S2P using similar 280ah battery for sprinter with 220amp alternator and 680w solar when driving or 1100w total possible when parking in right location when I can use 2 extra panes that are slide out . I am also planning to use 2 orion dc to dc.. Do you think it would be better to enable one orion at the time ? and using 2 orions while driving highway?
Thank you you mansion about how hot they get .I will design it with a fan in mind.
No alternator heat checks. I'm trusting that the 80 amp limitation recommended by Mercedes is solid and that the alternator is smart enough not to cook itself. I did put an amp meter on my wire run to the alternator and confirmed that the Orions are not pulling more than 80a. They will pull up to the mid 70's at times, but that's about it. The 80 amp limit was a fairly recent change for Mercedes. They used to limit the aux connection to 40a. Depending on the year of your van, you might check what the limit is. I know a lot of people ignored the old 40a limit with no issues, but I guess that's a personal decision.

I've thought about only running one Orion (or just turning them both off) when I don't really need to charge. That would save a little gas and wear the tear on the alternator, but I've only done it once and I just leave them both on now.

Your solar setup sounds really slick. I may be looking to add more panels later. Any pics you can provide of your setup and slide out panels would be appreciated.
 
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This is my build , the second identical module will be next to this one. Still waiting for sprinter so work is done on the backyard
 
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This is my build , the second identical module will be next to this one. Still waiting for sprinter so work is done on the backyard
That looks good, really ambitious. I can't quite understand all the workings here, but it looks like you've put some serious time/thought into it. I've seen some other posts from a guy trying to productize some fold/slide out panels. If someone could come up with a reliable design that is easy to deploy, I think there is a hot niche market for this with the exploding interest in off grid RV systems. If I could hit a button and turn my 400W array into 800 or 1200 without climbing around on the roof or worrying too much about wind, I'd buy a system like that today. Automatic fold out solar panels have been used in space for decades, how hard could it be....?
 

blutow Thank you​

You right there is lots of work on this solar. I have extra time because do not have sprinter yet. The sliding panels 2x 195w is pretty easy to do operated by air cylinder and stainless slides.
The most challenge is the tilting because I do not want to be the rack too high and 4" is too little for electrical actuator to lift pretty heavy 340w panel. so the will be additional couple cylinder for lifting panels before actuator take over. Not ideal but may work.
My previous sprinter I built in 2006 had generator and lp gas, all that weight now in new sprinter 4x4 will be in solar and no more propane/generator.
 
Re-reading your build thread as I'm finally starting to put mine together.

I see you put two sets of batteries to a combiner switch. That makes a lot of sense so you can shut off half the battery banks to service while still keeping power up.

Question: for the Victron voltage sense wire, are you running that to the combiner switch? It wouldn't be the exact voltage of the batteries, but really close, and that way no matter which way you had the combiner switch rotated it would still work. Thanks!
 
Re-reading your build thread as I'm finally starting to put mine together.

I see you put two sets of batteries to a combiner switch. That makes a lot of sense so you can shut off half the battery banks to service while still keeping power up.

Question: for the Victron voltage sense wire, are you running that to the combiner switch? It wouldn't be the exact voltage of the batteries, but really close, and that way no matter which way you had the combiner switch rotated it would still work. Thanks!
Good question and something I debated. I ended up just taking system voltage from the smart shunt and not using the voltage sense from the multi. The smart shunt is right there at the battery switch, so there was really no place further upstream to take voltage for the entire battery bank. I guess I could have taken it 2" closer to the batteries by putting the lead on the output of the switch, but there isn't going to be any measurable drop across that short span of copper bus bar. The cerbo allows you to choose the voltage reference source for the entire system (except the Orions).
 
If you don't have the smart shunt or BMV right next to the battery switch, I think you are on the right track taking the voltage off the output side of the switch. It's going to be the most accurate reference point.
 
I ended up just taking system voltage from the smart shunt and not using the voltage sense from the multi. The cerbo allows you to choose the voltage reference source for the entire system (except the Orions).
I went the same way too. I think it's the best way if you have the full Victron setup.
 
Thank you for that feedback, it makes sense. Slowly all coming together in my head!

Just finished capacity test on the first 280ah 12 battery. It took a few days to charge, top balance, and capacity test. For capacity testing I'm using that same Chinese rig you used blutow. It got quite hot when pulling the max wattage of ~12 amps, so I dialed it back to 6amps where the fan doesn't run much and it's pretty cool. Of course, that's a ridiculously low c discharge (.02 c!).

For charging I'm using a victron smart charger which puts out 18 amps. I have the 3000 quattro too but it's currently being used on our boat (where I live running off old battery bank and can't afford to lose power) so I bought a separate charger just for all this testing.

While discharging, I noticed the Delta in voltage was about 0.005 volts down to the last 10% in the battery. During discharging the bottom 10% the cell voltage started spreading out all the way up to 0.090. So almost .1 volts between cells. BMS cutoff at 10volts, as advertised. As I started charging back up, the cell voltages came back to within .005 as soon as I got about 20ah of juice back in the battery.

Does this voltage differential seem normal to you? Did you see something similar? I'm not measuring internal resistance...
 
Thank you for that feedback, it makes sense. Slowly all coming together in my head!

Just finished capacity test on the first 280ah 12 battery. It took a few days to charge, top balance, and capacity test. For capacity testing I'm using that same Chinese rig you used blutow. It got quite hot when pulling the max wattage of ~12 amps, so I dialed it back to 6amps where the fan doesn't run much and it's pretty cool. Of course, that's a ridiculously low c discharge (.02 c!).

For charging I'm using a victron smart charger which puts out 18 amps. I have the 3000 quattro too but it's currently being used on our boat (where I live running off old battery bank and can't afford to lose power) so I bought a separate charger just for all this testing.

While discharging, I noticed the Delta in voltage was about 0.005 volts down to the last 10% in the battery. During discharging the bottom 10% the cell voltage started spreading out all the way up to 0.090. So almost .1 volts between cells. BMS cutoff at 10volts, as advertised. As I started charging back up, the cell voltages came back to within .005 as soon as I got about 20ah of juice back in the battery.

Does this voltage differential seem normal to you? Did you see something similar? I'm not measuring internal resistance...
Sorry, I totally missed this post/question. I'm sure you already have it figured out, but your voltage differential will grow wider and wider as you hit either end the capacity. I can't remember what % capacity it would start to grow, but I think around 2.7v and below is where I'd start seeing the separation increase. I honestly can't remember if they were getting close to .1v differential, but I'd say don't worry much about the discharge end. There is so little capacity below 12v in these batteries, there isn't much reason to go there. The most important thing is that they stay balanced at the top, so that charging can happen without having over voltage issues at the cell level. You can use that chinese tester to capacity test on each of your individual cells and then group by capacity if you want to optimize things, but I honestly don't know if it's worth the trouble. My experience after running my batteries for 6 months or so - they just work and I'm no longer constantly logging into my BMS to see how balanced they are. I still have one cell that doesn't get above 3.45v when charging and I'm planning to tear that battery back down at some point to check connections again, but it doesn't seem to be causing any issues.
 
Where are you located? I have 8 lishens 272 that I'm selling
I'm in central TX. I'm not really in the market for any more cells, but might be interested in buying 1 or 2 cells for backups if you are looking to break them up and are close by.
 
I'm in central TX. I'm not really in the market for any more cells, but might be interested in buying 1 or 2 cells for backups if you are looking to break them up and are close by.
No, I switched to 16 eve 304ah cells in my van, so I am removing the 8 lishens I have now but to sell just a 2 wouldn't make sense for me..
 
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