Originally Posted by chooch
Mainly we had problems because we were using deep cell batteries and were newbies and did not understand that we weren't supposed to let them drain all the way down. Also we did not store them properly in the winter. We are learning as we go and are convinced that there are some better batteries out there we just don't know for sure what to do.
Lithium are certainly better for several reasons but if you mistreat them your cost is higher to replace. You will need to remember to store them at around half-capacity and make sure no loads are on battery when stored. They can get very cold stored but will have to warm up before placing a charge on them. Some are sold with heaters built in and some use heat pads. I went with the built in heater option and it runs from the charge when needed. That avoids placing unnecessary draw on the batteries with a heating pad.
As with all batteries you should know the specs of the battery and set charging properly.
The lead-acid (or AGM) are over a century old technology that has and still is doing people well. They can be damaged in same cold temperatures as Lithium, contrary to popular belief. If left discharged they can freeze. As you have discovered lead-acid cannot be discharged based on their listed capacity without damage.
-can discharge safely to rated capacity
-charge at high rate up to full capacity (quicker)
-much easier maintenance
-might need different equipment if converting over from lead-acid
-have to warm up to charge in very cold weather
-cost (but long term cheaper)
-can only discharge to around 50% of rated capacity safely
-charge takes much longer by charging at full rate then slowing for several hours to get up to a full charge (longer gen run time, longer solar time)
-heavy (more than double the weight of a same rated capacity lithium, quadruple the weight at usable capacity)
-lots of maintenance unless sealed AGM but still replacing much more
-any charging system can handle
-no need to warm to charge
-cheaper (but long term more expensive)
I always liked 2-6V “golf cart” batteries but after making the switch to Lithium I’ll never go back! I have one 300AH LiFEBlue Lithium with built-in heat and it works great in my motorhome.