Lead acid to lithium batteries

[sanda]

Hi there
I have researched this forum and other information via google and still have questions on the conversion to lithium as it applies to my situation.
I am replacing two 12 volt acid batteries with two 100 ah lithium.
My converter is set up for lithium charging.
I have a 1500 watt inverter that powers the outlets in the trailer.
I have 330 watts of solar panels. These panels will charge at 14+ volts and step down to 13.3 volts float. (sunny day)
I will not be running a/c or fridge through the inverter.
Do I need to install a shunt for this conversion?
Do I need to install a dc to dc charger?
I have read that the battery cables must be the same length to assure even charging. Is this true?
I am concerned about cold weather charging as we camp in sub-freezing conditions sometimes. Seems the batteries that have internal heating are very expensive.
I'd appreciate any guidance from those who know more on this issue.
Thanks

 

[John Burke]

I put my Lithium batteries inside my closet that is up in the front. I did build an insulated box with a 12 RV water tank heater under them just in case. I would not go with two 100 batteries. For about the same price and weight go with 1 200 amp, or even better 2 200 amp ones. Never heard anybody complain they had too much battery. With 400 amps you can run your fridge also. Your solar panels will help a lot. You should get around 15 amps per hour, if you have 6 hours of good sun you have put 90 amp hours back into your battery bank. If you use 120 amps a day that is a 30 amp loss a day. That is not bad, In a 5 day period you will use 600 amp hours, you will get 450 from your solar and the rest from your battery bank. With 200 amp battery you would be good for those 5 days. Depending on how much you boondock I would consider adding moe solar. You need to figure that out. My convertor is set up for Lithium also, goes to 14.6 and solar will go to 14.5. With the solar you would not need a DC-DC charger. With the two batteries I hooked them together a few inchs away from the battery and used a buss bar for all my charging and power draw sources. Made my cables from the batteries the same size and lengths. Makes for more even draw and charging. Should not need a shunt, but up you. I would really look at going with more battery capacity and solar/ Down the road you will probably want more, and it is a lot easier and cheaper to do it all at one time. Like I said, you never hear somebody go " wish I would have gone smaller". I have been very happy with my setup in my RV. I also did the same in my cabin just with a larger batteries.

 

[sanda]

Thanks for your response . All good points and will follow your suggestions