I bought 2 of the 100AH Group 31 size 12V batteries for my RV in February 2014. They do all that they claim. I now have a full 200AH at my disposal for a fraction of the weight and in the same physical size of my old AGMs. I also bought the dual 15amp charger they sell because my old charger never put out more than 13.4V and thus would not fully charge the LiFePO4s. SmartBattery had the manufacture install their LiFePO4 algorithm in the charger for nothing extra. I have nothing but very high praise for this company. I peppered them with tons of questions over the better part of a month and they were quick to respond and researched what they didn't know for me. When I did buy them, they shipped them out quickly and I received them within 3 days. The charger came even faster and arrived the next day. I had some followup questions and their responsiveness in answering them was just as fast and thorough as before I bought them. Here's a little about my early experience using them in my RV for others who may be interested: Some things are quite different with the LiFePO4s. With my 15 amp circuit at my house, it takes 2 cycles to fully charge them as my new charger shuts off after 16 hours and it needs longer than that to charge from a deficit of some 150AH out of my 200AH capacity. I haven't had it on a 30 amp circuit yet. To start charging, I have to disconnect the shore power, then connect again for the charger to start again. No float. I had a trickle charger that shunted a few amps to the engine battery to top it off when I was on shore power but the higher voltage from the LiFePO4s made it think it was on shore power and sipped power from the batteries. So that is disconnected now. My engine alternator charged them nicely while driving but just like on shore power, the BMS shut off the charging when they were full. No floating. Short driving periods resulted in some charging each time but it wasn't long enough to fill the batteries. My trimetric battery monitor shows the AH used after being off charging but while charging, it reverses and shows far fewer AH without me resetting it. That is, I use 150AH but when the batteries are full after a charge, it shows 4AH an hour or so after it is done. I guess it is measuring the deficit from full. I never saw that with the AGMs. When the batteries are full, the charger gets shut off and won't start again no matter how long or how much juice is used unless it gets disconnected from shore power and then reconnected so I have to pay more attention to the charge levels when plugged in.

Can't go wrong with Lithium Ion. Bought six 100amp batteries and they've been in continuous use for over a year. I'm still getting about 100amps out of each of them. Look forward to continued use for years to come.

I bought my first deep cycle lithium ion battery nearly two years ago from Lithionics and it has performed flawlessly, weighing in at only 28lbs for a 100amp that last all day and then some and recharges in under 3hrs. Its finish and build quality are good, but I just received a new 100amp deep cycle Lithium battery from Smart Battery for the same price, which I bought so I can have 24V trolling. The build quality is outstanding, the first one looks like it was built in a workshop with a riveted top section and battery posts that flex the top plate housing when you apply force to tighten them. The Smart Battery is jet black one piece case that does not flex and comes with a carrying strap with brass and stainless posts, and is smaller in size than my first one. The whole package is extremely solid and professionally finished compared to the first lithium battery I bought. This battery really looks the part of a top quality product that is a super lightweight and powerful deep cycle battery alternative to the lead acid equivalent product that can cost $2-300 and weigh as much as 80lbs and take over 10hrs to charge, I love it. The posts can be adapted for marine use by going to Auto Parts store and buying two M8 1.25 double threaded studs, this then allows for the use of a wing nut to accommodate easy removal of your electronic devices. My boat used to suffer from loss of speed with just one lead acid battery, not to mention how my lower back would suffer when I picked up that much weight. By the end of a hard days fishing I would be crawling along as the lead acid battery had lost so much of its charge. Now I have 24V goodness that zooms me about with no noticeable loss of performance as lithium batteries don't drop off in power like a lead acid and last from sun rise to sunset. Even just running the main engine starts to recharge the lithium battery between spots that was not noticeable with the lead acid.