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After much research, design and building my 12v LifePo4 upgrade to replace my two 6v AGM's in my RV is now complete and ready to install. I am very happy with the result and it will be interesting to see how it does through next winters' storage monitoring. I've attached my design file and...

Thanks for that link. Very helpful starting point for figuring out heating levels as I actually design and build the box. I also agree that my approach is likely too complex / unnecessary but part of this process for me is having fun designing and building.

At the moment I am leaning towards the JK because Overkill only has up to 120amp and the JK seems to be the only one with adequate active balancing without adding anything. However, you input is the first I've read about quality concerns with JK. Can you tell me a bit more about the failures?

I have done rather extensive reading on the subject of heating pads for LifePo4 builds. I'm not finding quite enough specific information to complete my 12v design, hence this new thread. This build will be 12v 302aH using EVE cells. I will be using 25watt silicon heater mats that many others...

I am really impressed with Overkill. Just wish they made a 200amp BMS since I want more peak current for confidence in starting my Onan5500. The JK spec's 350amp short term.

Interesting find! Concept could be used for sure.

Thanks for that link. Great summaries of available gear. Interesting comment about cold weather charging using low currents.

I want to design an insulated box with heaters for a 12v Lifepo4 battery build. I'd like to apply just enough power inside the box to keep the cells around 40 degrees without on/off cycling of the heat. E.g. - the colder it gets below 40 degrees, the more power will get applied to the heating...

I'm close to completing design research for my 12v DIY battery. In this thread I will summarize my analysis of the heater wattage needed based on my worst-case use case of off-grid winter RV storage. I need that batteries to stay active enough to run a remote monitor system. My Requirement...

Picking a BMS is the last step in my 12v battery project. I will be using 304 aH cells from EVE. From everything I've read getting a high balance current spec (1 - 2 amps) and overall high current spec (200 amps) is my best bet. I also definitely want bluetooth connectivity. I'm trying to...

I expect no more than 100 degrees F on the pads though designing for somewhat higher will be a good idea. Maybe 150. I just ordered poron sheets from mcmaster for another application so I'll take a look through their catalog. Good suggestion.

What kind of still foam will be ok long term with direct contact of the heat mats?

I like your setup though I plan to do something different. Thanks for sharing, unfortunately it doesn't help answer my questions.

Just 12v and I will look at the inkbird type solution though the challenge is all a part of it for me since I am a retired engineer. Smiles. Thanks for responding!

I have read and researched all the normal solutions. So, yes, I do my work ahead of just asking the same questions. What makes my investigation unique is looking for a variable heat control for which I have not seen in other posts. I may give up and go with the "tried and true" if I run into...

I'm going to build a 280aH Lifepo4 battery using sourced cells and BMS. Remaining concern is cranking power for the ONAN5500 genny in my RV. The cells can do 2C (560amps) for 30 seconds which exceeds the expected 350amp max cranking amps that the 5500 might want. Anyone have experience with a...

I won't be heating the cells past 45-50 degrees F. The wattage of the heat pads will be around 20 watts total spread across the sides and bottom. I don't want to create hot spots which is why my original questions focus on use of an aluminum plate in contact with the heat pads. I think its...

Thanks. That is a pretty handy calculator, but I'm not certain I understand how to use the number. The text says to multiply by wattage of the solar panel but how does that make sense. The chart gives kwh/m2/day. If I assume 15% solar efficiency of the panel, and the panel is 58"x 26" that...

Thanks. I did find many of those search link but your query has a couple more. The Overkill BMS documentation is great. The only think I'm concerned about is that it uses passive balancing. The JK uses 1 or 2 amp active balancing which is desireable from what I've read? Can I get your...

Yep, that particular controller is all wrong for the battery application. A PWM approach to controlling heating pads would definitely work but the control circuit likely not worth inventing. So....I'm convinced to keep it simple and ordered my heat pads and temp controller. But doing...