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@F1uxCapacitor The 7-pin 12-volt line maxes out around 2 Amps which can only feed ~30 watts. I tried that and it's a non-starter. I definitely want to get the full 50 Amps/600 watts pushed to the RV batteries. When I tried using the 7-pin last weekend, it was a disaster and could hardly keep...

@F1uxCapacitor I have 2 100 watt folding panels that I've been using as well and may add some flexible solar panels to the top of the camper to charge via solar while driving. But there will be times when there's no solar charging so it can do the full 50 Amp via the TV if no solar charging is...

I have not yet set up the BMS, but I presume it would be able to handle 2 batteries. The manual outlines how to configure the BMS for the group of two. http://www.thunderstruck-ev.com/images/companies/1/VC1-Manual-20201014.pdf?1602695771461 I do not see a specific option to set the number of...

So I plan to run two U27-XPs in parallel with a Xantrex Freedom 2000 controller/inverter. How much benefit will I get from using the Thunderstruck BMS with this setup verses not? The Xantrex controller/inverter will give me high/low temp and voltage protection, but would not balance the cells...

That's a fair question. Ultimately I just don't want a capable carrying a high amperage outside the car and exposed to the elements on the undercarriage of a car. I also don't want it exposed to that much heat if available. It may be possible to do it, but it's not my top choice.

If anyone has expertise in the quality of used Valence U27 XPs, I posted the diagnostics for mine here and am looking for feedback: https://diysolarforum.com/threads/feedback-on-third-owner-valence-u27-12xp-quality.16351/

Thanks @Dzl I'll take a look at h/l voltage detection within the Valence internal module BMS. I hope it's there. I have a hunch it is.

@chrisski I'll write to Renogy for clarification, as this question seems to come up frequently and it is pretty crucial to determining the TV to RV amperage and wire guage.

@HRTKD I agree. I've concluded that I need 4 AWG at least. It's just the positive line though. I'm using Will's schematic and plan. https://www.mobile-solarpower.com/simplified-400-watt-fewer-wires-and-alternator-charging.html

Side note: I plan to wire these in parallel to a 12V Inverter/Controller. I understand that I'd need to use the external BMS for temp/voltage monitoring and automatic shutoff, is that correct? I plan to use this BMS: https://www.thunderstruck-ev.com/valence-battery-bms.html I may also add a...

@F1uxCapacitor I find your argument convincing. I'll feed this on the exterior with split loom.

Sorry to pile on late here, but I own a Renogy DCC50S and am considering getting something to better monitor the solar input. After all of your experiences with this, do you recommend using the DCC50S with the BT2 & DC Home app? Or should I find a 'better' solution?

Hi all. I'm setting up a solar setup with lithium battery storage and a 2000W inverter. The large inverter should be able to handle a 5K BTU Air Conditioner I have as well as a mini-fridge. I plan to use a 200W portable solar panel (Jackery is releasing one this year) and have two Valence U27s...

So, the fortunate thing about Valence U27s and likely all Valence batteries is that EACH module has its own built-in BMS for cell balancing. My inverter/controller (Xantrex Freedom 2000) has a high/low voltage and high/low temp cutoff, so that's taken care of. The only thing I would not have...

So, I've heard quite the opposite @WinnieVan and I may have been misinformed. What I have heard is that the INTERNAL cell balancing is taken care of by each module's internal BMS, however, the inter-module balancing requires the external BMS. I have not found a clear information link from...

Hi everyone. I'm a recent lurker working on a solar setup for an A-Frame camper. I plan to have a large battery bank for dry-docking. I purchased two Valence U27 XP's off eBay. Taking a risk, I assumed they had moderate use but the price was the best I've seen in a while so I snapped them up. I...

I just grabbed two Valence u27-12xp batteries as well and also plan on using the MPP Solar LV2424 as well. I've also read conflicting information on whether these batteries will have low/high voltage protection and temp protection. I'm also considering getting two Victron Battery Protect (smart)...

@chrisski check out the video. The performance is demonstrated live. It can charge at 50 Amps IF there's no solar charging. That's what it seems to show pretty clearly. The documentation and information are unclear, for sure. In the case that it IS maxed at 25 Amps, that would incentivize...

Thanks for the feedback @snoobler! I will grab that Capacity Tester and give it a go. I may post questions on using them here if that's okay. Looks like these batteries should have decent life left! I should note that these are 138AH so perhaps that lowers the discharge count a bit.

Hey folks, total nube here. I am working on outfitting my 2018 Aliner Ranger with a solar setup and large storage capacity for boondocking. I was able to grab two lightly used Valence U27 XPs (138AH) for a total of ~276AH in a 12V parallel setup. With this setup, I plan to use the Xantrex...

Thanks for the help. I'll only go with the Protect on the load side. Thanks!

@HRTKD I'm open to adjusting this. @Will Prowse suggests using the common ground, tied to the chassis, which is how mine is already wired for the solar. He also suggests the 4 AWG but perhaps that assumes a shorter run. Perhaps I'm not understanding what I should be doing with this setup.

Gotcha. Yes, by 'load', I would be referring to a 12V Fuse Block, though I do plan to use a Controller/Inverter with these batteries. The documentation on using the Victron protect is a bit confusing but I had the impression that if I had it on the 12V load side, that might give some peace of...

Thanks for sharing that @F1uxCapacitor. I came across that video and the comments helped me wrap my head around the 'common ground' connected to the chassis. Thinking about it more, I may have situations where I won't have my tow vehicle hooked up to the trailer, but may want to plug in the...

@sunshine I've decided to go with both pos and neg cables. I realize now that other systems may have bigger chassis or a different setup. I don't think the common ground to chassis will work unless my popup is connected via the hitch to the TV and I think two cables will be a more trustworthy...

Oh gosh no. This is for a small popup This is for a small popup camper. 4 would be major overkill for our needs and for the weight of the trailer.

I have two Valence U27s that I plan to use in parallel with a solar setup in my pop-up camper. I know that there is a BMS for low voltage usage of the U27s but I'm wondering if that's going to be at all necessary or helpful or worth the price. I have seen others that don't use the BMS in this...

@GSXR1000 do you have a recommendation on a solid 20amp breaker that works well?

Thanks for the feedback @Rocketman! I was not aware of the need for the Class T Fuse on this system so I've been digging into that. One thing I did find is that the Bussman MRBF Fuses are Amperage Interrupt Rated to 10,000 AMP. Would this be sufficient for the two 138Ah Valence Batteries...

@Rocketman from what I've gathered from the Valence U27-XP module user guide, they have a short-circuit current "in excess of 2000 amps"... that isn't entirely clear, but it suggests to me that it may not be higher than 10,000? I'm not entirely certain...