Most reacted posts

Got LiFePO4 batteries to install and a new inverter charger on its way for my motorhome. Now I hear lithium batteries don’t “like” to be charged to 100%, more like 90%, and certainly shouldn’t be stored above 90% but rather 50%. Is this true? And, if so, can I program a Magnum MS 2012...

Thanks, The way I plan to wire the panels and looking at their ratings will be OK for the Victron 150/100. 220w panels, series parallel. Vmp 22.42, Voc 24.9, Imp 9.37, ISC 9.85.

I’m curious why a fuse should be put on eac battery rather than the one on the main cable attached to battery closest to the inverter/charger? Also, the protection from the solar controller, a Victron Smart Solar MPPT 150/85-Tr VE.CAN, is provided by a 100a CB close to the controller. Any...

I’m getting closer to installing my LiFePO batteries. I just read something I hadn’t thought of before. Actually, in a way the subject did come up. Previously, the issue arose that lithium house batteries may not be very useful to help the chassis batteries if they are too low to start the...

I’m installing 4 12v lithium batteries in parallel. Simple enough to to set them side by side in a row with equal lengths of cable between them. Then attach the main positive cable off one end of the set and the negative off the other end. Now, with some rearranging I can add a 5th battery if I...

I don’t have that capability.

Is that amp output rating of the solar charge controller, not the amp output of the panels?

Just watched Will Prowse’ comparison of 12 vs. 24v systems. He had me convinced to go 24v except for a couple of things. He is opposed to charging from the engine alternator. He said there were other options but didn’t say what they are. I think using the alternator guarantees fully charged...

Great information. Exactly the things I need to know.

In my motorhome I have 2 SK12V206 lithium batteries charged by a Magnum MS2012 inverter with the ME-ARC remote display and a ME-BMK battery management kit. I am thinking of installing a Victron BMV-712 Smart battery monitor with Bluetooth. I understand it might be more accurate especially in...

Three of these panels are about my limit, spacewise. I can fit 6 of the 210a Continuous Reasorces ones though which would only be 13.5% more wattage than 3 of the 370w units.

When using a wire size calculator which solar panel volt and amp measures should I use? Vmp or Voc? Imp or Isc? And what percent voltage drop should I shoot for? Is it worth it to use 4 AWG to get 1% drop if 6 AWG is 1.5%?

That’s 1500 watt hours and less than 40% of capacity based on time of year and latitude.

3 Santan $644.66 pickup at dock. W&S $1355.42. 4 210w CR $776.00 w/free shipping(I think). During most of day should be no shading issues from items on roof. I like the tech of the W&S but over twice the price of Santans?

With the 4 210w panels it looked like a no brainer to go series/parallel. 3 WS panels, all series, I think. Santans? Not sure.

Thanks. Great information. My installation is on a motorhome. The distance from the combiner box to the charge controller is no more than 25’ so 50’ total cable. An online wire calculator just asks for voltage and current so your answer helps a lot. Ed

I watched a webinar about solar systems on RVs. It was mentioned you can be less careful about running your batteries low if you have a generator. I wonder about this. My generator uses the house batteries for starting so you have to not let them get too low. I assume this is especially true for...

4/0

Thanks Rocketman. You read between the lines and deduced what I shoulfpd have said, the batteries will be in parallel. I have 2/0 wiring from the factory, which has been sufficient, although I have never touched for temperature after generator start. Your point about fuses is well taken. This...

I presently have 2 SOK 12v 206ah lithium batteries wired in parallel. They are a little over 2 1/2 years old. I’d like to add another one next spring. However, it seems I remember reading in the past that lead acid batteries of different ages should not be mixed. Don’t know if having them in...

Your right about scale. I miscounted the squares on battery 5. I’m not quite following the lines. Where is the positive connection for the top two batteries. Same for positive and negative ones for the middle. And what does cable 2 connect? Negative to negativ, I assume and not the positive of...

I apologize, should have added this to the original post for clarity. I think my questions have been answer but this might help if there is more information. I will be using 2/0 wires. Many thanks to you all. Ed

I followed the advice of a van systems solar internet guru and installed a 250a MRBF fuse in a fuse holder directly to me positive terminal on a SOK 12v lithium battery bank. He said in light of the scarcity and prices of Class T fuses that would be acceptable. Since then another forum thread...

I don’t think I was clear. Yes, put a fuse as close to the battery as possible but why put a fuse on EACH battery positive terminal rather than just the one on the downstream battery attached to the cable to the inverter/charger? The upstream battery of the two is attached to a very short cable.

OK 12v lithium batteries in parallel. Max charge current 70a, recommended 40a. Max continuous discharge current 100a each, peak 200a(3sec). I believe I will put a MBRF or ANL fuse on the positive terminal or close to it of each battery. What size should it be? I’ve read 120% of either max or...

OK 12v lithium batteries in parallel. Max charge current 70a, recommended 40a. Max continuous discharge current 100a each, peak 200a(3sec). I believe I will put a MBRF or ANL fuse on the positive terminal or close to it of each battery. What size should it be? I’ve read 120% of either max or...

Thanks

I replaced my 4 6v AGM batteries with two SOK LiFePO4 12v 206ah batteries with no other chamge to the system. There is 4/0 cable from the inverter/charger to the batteries through a cutoff switch with no fuse in the line. There is a 2/0 cable from the cutoff switch to the house items, as best I...

BTW the batteries are connected in parallel.

Good point. Thanks