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Curious why you are concerned about startup voltage? Unless you plan to run them all in series in one string at higher voltage, which I wouldn't recommend. Shade on just part of any one panel will shut down the whole string. I have 2 parallel strings of 2 in series. One pair at the front of...

I had recently bought a newer version with the larger connectors. I sent Louis my older version SBMS0 with the smaller connectors. My understanding is that logically they are the same.

Electrodacus SBMS0 users, I have been in touch with @Louisvdw about a Venus OS driver for SBMS0 and I have sent him a unit to use for integration and testing. If you have interest or input on a driver for SBMS0 please reply. @Louisvdw would you like the SBMS0 discussion to be in a separate...

Actually you misquoted me, that question you quoted me as saying was from @APhoton. I’d still like to hear from him on it. Dacian’s DSSR solar charging is completely optional, his BMS works fine with MPPT. So that is not a constraint. I use a Victron MPPT in my system. I find his BMS to...

That's pretty vague... who are the "some" and what are their objections?

Any news on SBMS0 integration with VenusOS driver?

Just saw this... yes you have to download the Two-Signal BMS Support to use it. See this app note: https://www.victronenergy.com/uploa...battery-systems-to-Multis-and-Quattros-EN.pdf

It only introduces a single point of failure if you choose to design your system that way. Totally up to the system designer. Before commenting more on that, I'll just note again that I design for the BMS to have primary control of normal charging--like Cal, who I originally got that idea...

Remember this is in Vehicle Mounted Systems, this is not about Romex with 90C insulation in a house. At least I know my local building dept. doesn't care what I do in an RV. That said, I do like to reference both ABYC and NEC. What it is about is safety with margin (ampacity, insulation...

Here's a good article from same guy on AC wire sizing in boats. Need to factor in bundling etc. https://shop.pkys.com/Sizing-wire-for-AC-circuits_b_45.html I bought the Ancor 10/3 for my 30A main shore power wire and 12/3 for 20A circuits.

Have you looked at Blue Sea info? They have some good material. I like their Ampacity table, includes insulation temps and also bundled or not. They also have a calculator that factors in both ampacity and voltage drop. Other good resources too, but I use these two things all the time. Edit...

I have not yet used my new electrical system yet. I've had it working on my bench with the Electrodacus BMS for some months but now moving into the van. But I don't think an automatic diversion system is needed for a van. You'll probably be turning off your inverter when not using AC anyway...

This looks very similar to my own system. I think you'll be happy with the Electrodacus BMS. A couple observations: You need to power the DEXT16. There is a "+" and a "-" terminal that need battery power. On your diversion water heater--not sure what you're using, but the two elements...

I was just running with your example which had 3.2V. At 3.4V it wouldn't matter too much, the battery is basically full at that point. My second plot attempted to illustrate a 50C rise. And yes it seems like it would be in the 4-5A range if you also shifted the battery IV curve 1.6V to the...

Just to check, I extrapolated from the 25C and 50C curves to guesstimate a 75C curve. Temp coefficients are linear so I just drew a curve shifted down by same amount. I guesstimate 6.0A at 75C, still not a trickle charger.

Yes I'm an electrical engineer... @Cal, I think you're missing two points I'm making. First is that Dacian is not designing for maximum power out of a panel on a hot summer day at noon. He is designing for highest integrated total power over the course of a day, and weighted toward winter...

The 14AWG 70ft quote from Dacian came after my post. Personally I'd put that in the class of long cable runs for wire that thin. To be clear I'm not yet sold on his DSSR theories but am curious and do plan to test in my van at some point. 2 panels on DSSR, 2 panels on Victron MPPT, side by...

Dacian lives in the Canadian prairie so he optimizes for winter when sun angle is low. In summer there is excess solar so efficiency is less important for him, and not too many 100F days up there. He does say if you're in a warm climate and long cable runs then maybe go with 72 cell.

I'm also in the upstream camp, and this is one good example of why. Here's another: what if you had an AC short to your DC negative return. The "downstream" design would disconnect the hot DC negative from safety ground. I can't see any good that will come from that. I know this thread is...

I bought this one for $45, I had needed one a few times already for other reasons so was time to buy one: https://www.tekton.com/1-4-inch-drive-dual-direction-click-torque-wrench-trq21101 While 10 in-lb is the lowest major increment, with the vernier has 1 in-lb markings and you can go a bit...

I ordered online from Lee Springs. After looking at spring rates, I ordered two different ones to try: LHL 625D 03, $3.97 each LHL 500D 03, $3.40 each You have to balance having enough pressure to get desired compression against having enough travel to accomodate any expansion/contraction...

Here's another option on springs from my post back in May... https://www.leespring.com/compression-springs-hefty?search=LHL625D I did buy some but never did install. Maybe I'll try them now.

I can help on part of your questions... One observation though, when you say A I think in general you are meaning Ah, right? Amp-hours not amps. Also, check out the electrodacus forum, you can access it from the web page. 1) I'll defer to others here. 2) Whether to change your SCC is a...

Yes on the sense leads from the shunt. Series R followed by shunt C. Depending on the input circuit if you want to keep it balanced you could put a series R on both sense lines (same value on each lead) and then a shunt C after the two Rs. BTW after my earlier post I looked at the...

Yes that's right, for 2P it is simple. As long as you connect positive to one of the two cells and negative to the other cell, it will be balanced. Plus I'm guessing you'll have equal-length bus bars joining the 2P cells. The bus bars will be much lower resistance than say 8' long cables...

A couple other points on the 24V topic. I started out designing a 12V system and ended up with 24V. Main reasons: 1) It lets me use the full surge capability of a Victron 3000VA Multiplus inverter. For 24V, Victron specifies a 300A fuse, for 12V a 400A. Ideally there would be a 2X...

A few months ago I was looking at this and came across the same article. I was looking at undermounting four Battleborn batteries, two on each side of the van. Using the cable lengths and sizes I would need, I saw variation of up to 6A charging between batteries on a 100A overall charge (i.e...

They are optocoupler outputs with two output pins, so it depends what you connect. Outputs are connected when enabled, open when disabled. You can't invert the logic in SW in the device, which I think is your question. What would you be driving with it? Not sure of your background or if you...

Dang, I thought about the surface area! Actually I meant total emission factoring in area! Er... Anyway, not trying to be too flippant. I do get that there are insulated boxes and in true continuous high current applications you want to be careful. In my own application I'm about 4X...

Yes that's right, in my 1P8S setup there are 7 bus bars so there would be a total of 17.5W of heat sinking into my 100 lb pack, about 1 cubic foot, if I was actually running 445A continuous. 17.5W in that volume is not that much. Unless of course you put it in a hermetically sealed highly...

That's exactly my point. A cell is a lot bigger with more mass and more radiating surface than an LED. It will feel less warm than a 2W LED bulb much less an LED. Well we'll just disagree. A marine environment is the most hostile and unforgiving there is, outside of spacecraft. I'm...

I understand resistance vs length. My point is that models may assume a long bar as a simplifying (and conservative) assumption. However, when you have a 3" bus bar heat sinking into large battery bank, those models will overstate temperature rise. In the real world, 2.5W will feel hot to...

You don't have to buy a roll. From the marine wire sources that @Dzl listed above you can buy by the foot, specify your length, and even have the (tinned) lugs crimped so you have finished cables at a pretty reasonable cost. And then you have tinned cables with tinned lugs that will do a lot...

Plus it is tinned

OK so let's do some power dissipation. 4/0 wire has 107mm^2 area and a resistance of 51mhom/1000ft. So for a 3" bus bar length, the resistance is about 13uohm. ABYC rated current of 445A means power dissipation would be 2.5W per bus bar. I don't think that's going to get very hot. Edit...