Chas B. Wolfson, SASS #11104 Posted November 19, 2025 Posted November 19, 2025 (edited) As if I need another project, replacing the travel trailer batteries are on the list over the winter. I currently have four 100AH AGM batteries installed that have gone way past their advertised life span. The trailer has a convertor/charger and a separate 1500W inverter. We use two portable 400W solar panel arrays mounted on 50' of cable=800W total and an Onan 4000W Emerald GenSet. I am seriously considering going the lithium route. I have found many that would work, especially one that is basically the same dimensions as my current AGM unit but produces 300AH/battery, 1,200AH total. I would also replace the convertor and inverter with a single inverter/charger, rated at 3000W or maybe a 4000W unit. Also have a fixed 180W solar panel that might go on the roof giving a total of 980W. So my main question is aimed at primarily someone that has made the switch to lithium batteries. Pros and cons please comparing the older style to the new. Also would like to hear from those that have strictly had lithium. This will be a fairly costly change out if done. Have to change my solar chargers also due to the required higher charging voltage of the lithium style battery as well and all my cables to a heavier gauge, batteries and new inverter/charger. My research to date shows that with the four 300AH batteries and the amount of solar I have available, I could run the RV AC unit without the generator running for the most part and all the interior circuits would be active without the generator running. IE: At a match or NASCAR race and being able to turn on the coffee maker before 6:00A.M. Thank you in advance for any informative replies. Chas B Edited November 19, 2025 by Chas B. Wolfson, SASS #11104 Quote
Eyesa Horg Posted November 19, 2025 Posted November 19, 2025 I put 2 of the inexpensive Dr. Prepare 100ah Lifpo4 batteries in my camper. Moved them to under the bed. Added a 2K inverter with remote start so I can make coffee without a generator. I'm tickled with it! I have 250 watts of solar and on a good sunny day at the range, I'm back to full charge by 11:30. My camper has one of those 12 volt only fridge which has been an issue since new. It will use about 25 to 30 percent overnite. If it's overcast for the weekend, I'll run the generator and a 40amp charger to bring them back up in a few hours. Used to run it everyday for 10 plus hours to bring lead acid golf cart batteries back. The beauty to me is the lithium are light and you can safely run them way down without issue compared to lead acid. Only issue I had was that the built in charger won't charge them all the way. So I just just turned it off and put a charger in with the batteries and plug it in right next to the bed if needed. Was about the same cost(actually a little cheaper)as upgrading the camper charger/converter and I get the benefit of having a portable charger. Which I've already used to help out fellow campers! I did upgrade the cheap camper wiring as well when I did a couple years ago. 1 1 Quote
Happy Jack, SASS #20451 Posted November 19, 2025 Posted November 19, 2025 After living "off the grid" for 30+ years now I have a LOT of history with batteries, wet, agm, nickle/iron, and lithium. A currently have 1 set of nickle/iron and 1 set of lithium. The inverters are not a problem BUT lithium batteries are VERY particular about charging. A typical battery charger or the one in most RV's are not suitable for correctly charging lithium batteries. I'm running 600amp hours at 48Volts at both sites. 1 Quote
Sedalia Dave Posted November 20, 2025 Posted November 20, 2025 Biggest con is LiFePo4 batteries need special care when it drops below freezing. Charging them when the temp is below 32F will permanently damage them. Their capacity is significantly reduced when they are cold. Quote
WIld Weasel Posted November 20, 2025 Posted November 20, 2025 Happy Jack has the best set up. Run both so if the temperature drops you don't suffer and insulate/heat them well. On another note try to put them ANYWHERE but under your bed or near the exit route. FIRE is the biggest threat and rewire anything that was stock connected to it. The connections are key and use thread compound on them so they don't corrode or loosen. Check the connections at least twice a year. 4 times is better with a torque meter. I took care of our MRI and CT battery back up systems and that was drilled into our brains at the schools. But watching the RV and battery YT videos as well showed me more as I was researching off grid living. Remember you only have seconds to get out of that traveling coffin if fire starts. Treat that gen set and fuel carefully and have a suppression system and extinguisher handy by both sides of the bed as well as the door. Seconds count. A lot of the trailers have the batteries by the steps and such. RUn good HD copper wire and I'd go 1 guage size larger (smaller #) than they say. Keep everything neat and tidy use insulated standoffs as well and check for chafing after your trips. Extra time installing means less time along side the road or in the campsite repairing. Use good quality connectors and crimping tools, insulate the terminals and heat shrink carefully. It took me a long time to rewire ours just to sell it after one camp out but the guy I sold our 20' to had only 1 functional outlet left in his 34' unit. He wanted to downsize and loved all I did to ours. He bought a Predator 3000 watt quiet generator and 2 120 gal propane tanks to set up at the park for emergencies. Had to use it for a couple times the electric went out in the park. Happy boy. Can afford his lifestyle now. Other people at the park helped him insulate the bottom of the trailers with foam blocks. So it's doable in the 20's as well as the 90's here under the tree's with the A/C. Quote
Eyesa Horg Posted November 20, 2025 Posted November 20, 2025 9 hours ago, Sedalia Dave said: Biggest con is LiFePo4 batteries need special care when it drops below freezing. Charging them when the temp is below 32F will permanently damage them. Their capacity is significantly reduced when they are cold. From research I did back a couple years, Lifpo4 are not flammable and won't explode. No damage from charging in the cold as the internal BMS just shuts them off. It also doesn't get that cold inside the camper when we're using it. When I winterize, they are stored at 80% charge in a heated garage for the winter. I'm surely no expert, just basing my decision on what the battery company informed and others experience. I upgraded the wiring to #4 copper from the factory #6 aluminum. Also ran a separate negative to each power point. I.E. the front corner of the trailer and behind the converter. Bonded the negative to the frame as well. With that damn 12v fridge, this was best upgrade I've done. Haven't had any issues and the Lifpo4 batteries were cheaper than Trojan golf cart batteries and weigh a third as much! And I'm loving being able to make a cup of coffee or chocolate whenever I want without starting a generator! 1 Quote
Sedalia Dave Posted November 20, 2025 Posted November 20, 2025 47 minutes ago, Eyesa Horg said: From research I did back a couple years, Lifpo4 are not flammable and won't explode. No damage from charging in the cold as the internal BMS just shuts them off. It also doesn't get that cold inside the camper when we're using it. When I winterize, they are stored at 80% charge in a heated garage for the winter. I'm surely no expert, just basing my decision on what the battery company informed and others experience. I upgraded the wiring to #4 copper from the factory #6 aluminum. Also ran a separate negative to each power point. I.E. the front corner of the trailer and behind the converter. Bonded the negative to the frame as well. With that damn 12v fridge, this was best upgrade I've done. Haven't had any issues and the Lifpo4 batteries were cheaper than Trojan golf cart batteries and weigh a third as much! And I'm loving being able to make a cup of coffee or chocolate whenever I want without starting a generator! Personally I think they are a great upgrade and I will be installing them in my next RV. I just wanted to point out that use in below freezing temps needs some consideration. Some of the ones I looked at had internal heaters controlled by the BMS to prevent damage in freezing temps. There also seems to be a big disparity in prices. Still researching the why seeming similar batteries have such different costs. 1 Quote
Chas B. Wolfson, SASS #11104 Posted November 20, 2025 Author Posted November 20, 2025 Nothing set in stone yet but this product is high on the list: 12V 300Ah MINI LiFePO4 Lithium Battery, Bluetooth Lithium Battery, 200A BMS, up to 15000 Cycles, Max.3840Wh Energy with Low Temp Cut off, Perfect for RV, Solar, Trolling Motor - 4Pack Visit the PUPVWMHB Store 4.6 4.6 out of 5 stars (180) | Search this page $1,236.00 with 7 percent savings -7% $1,236.00 List Price: $1,336.00 List Price: $1,336.00 Price history Or $56.61/mo (36 mo). Select from 3 plans Get a $250 Gift Card: Pay $986.00 $1,236.00 upon approval for Prime Visa. No annual fee. Delivery & Support Select to learn more Ships from Lifepo4 Battery - US Non-returnable. Transportation of this item is subject to hazardous materials regulation Customer Support Style: 12V300Ah - 4Pack 12V200AH Bluetooth $289.00 $289.00 12V300AH Bluetooth $309.00 with 11 percent savings $309.00 $349.00 12V300AH - 2Pack $618.00 with 7 percent savings $618.00 $668.00 12V300Ah - 4Pack $1,236.00 with 7 percent savings $1,236.00 $1,336.00 12V330AH Self Heating $389.00 $389.00 24V100AH $299.00 with 9 percent savings $299.00 $329.00 Brand PUPVWMHB Product Dimensions 13.58"D x 7.48"W x 9.64"H Terminal M8 Automotive Fit Type Universal Fit Manufacturer Vehicle Service Type ATV, Boat, Golf Cart, RV Voltage 12.8 Volts Battery Cell Composition Lithium-Phosphate Item Weight 59 Pounds About this item 【APP monitoring】Our lithium battery has listened to the suggestions of many users, so we have developed a special battery with communication function so that you can easily monitor the status of your battery in real time. This includes current, voltage, temperature, cycle, etc. Just download our APP to the phone according to the instructions. 【Advanced Technology】PUPVWMHB 12V battery is based on industry-leading technologies and manufactured using advanced industrial technologies. This model 300Ah LiFePO4 has excellent and reliable performance with sufficient battery capacity, the capacity of the monomer is still greater than 80% even after 2000 cycles. Lithium 12V can therefore be used immediately after charging, regardless of the charging status. 【Max. 61.44kWh Perfect for solar system】PUPVWMHB LiFePO4 battery 12V300Ah can be connected in series and parallel to achieve larger capacity (max. 1200Ah) and higher voltage (max. 51.2V). The max. Energy is 61.44kWh, the max. load power is 40.96 kW, which is easy for you to use anytime and anywhere, and makes LiFePO4 300Ah perfect for solar battery home system, stand-alone system, home power supply 【200A BMS & Safety & Environmental Friendliness】The stable chemical structure of lithium iron phosphate ensures that the LiFePO4 battery will not burn or explode even under high temperatures, short circuits, shocks and falls. Maximum safety based on the UL test certificate for the cell in the battery. And it contains no heavy metals and rare metals and is more environmentally friendly. 【5-year warranty】Since the lithium-ion battery contains no acid, you can safely mount it in any position. This makes Li-ion batteries perfect for boats, motorhomes, camper vans, caravans and off-grid applications! All PUPVWMHB batteries come with a five-year warranty. 24 hour friendly and professional › See more product details Quote
Chas B. Wolfson, SASS #11104 Posted November 20, 2025 Author Posted November 20, 2025 Possible inverter/charger AIMS Power 3000 Watt 12 VDC Pure Sine Inverter Charger 120 VAC Output 100A Charger 30A Transfer Switch PICOGLF30W12V120VR Visit the AIMS Power Store 4.0 4.0 out of 5 stars (384) | Search this page Amazon's Choice $1,120.89 with 15 percent savings -15% $1,120.89 List Price: $1,323.00 List Price: $1,323.00 Price history Or $51.34/mo (36 mo). Select from 3 plans Get a $50 Amazon Gift Card instantly upon approval for the Mercury Visa Signature Card. Learn more Delivery & Support Select to learn more Ships from Autoplicity ✅ Returnable until Jan 31, 2026 Customer Support Size: 3000W 1000W $682.00 with 8 percent savings $682.00 $741.00 FREE Delivery Saturday 1500W $815.00 $815.00 FREE Delivery Sunday 2000W $942.00 with 7 percent savings $942.00 $1,017.00 3000W $1,120.89 with 15 percent savings $1,120.89 $1,323.00 4000W $1,412.00 $1,412.00 FREE Delivery Mon, Dec 1 4000 Watt Split Phase $1,492.00 $1,492.00 Bundles with this item Brand AIMS Power Electrical Output Waveform Pure Sine Wave Recommended Uses For Product Home, Office, RV, Cabin Power Source Battery Powered Wattage 3000 watts About this item POWERFUL: 3000W continuous, 9000W surge for 20 seconds, 25 amps, 120VAC pure sine clean power, low frequency, auto transfer switch and 100A smart battery charger for 8 different battery technologies including Lead, Gel, AGM, LiFePO4 and more. PROTECTIONS: Overload, over temp, high voltage, low voltage, short circuit, internally fused, low and high voltage alarm, cooling fan, and isolated ground neutral. FEATURES: GFCI Outlet, AC direct connect terminal block, charge current control dial, dip switches to set priorities, auto gen start, conformal coated, power save mode and battery temp sensor. Only one set of cables needed. Optional remotes available. APPLICATIONS: Ideal for applications going back and forth from shore/generator and inverter power automatically, offgrid and back-up power. Homes, boats, RVs, solar, mobile business & work trucks. 12 Volt more efficient and can use smaller cables. TRUST AIMS: Buy with confidence. In business for over 20 years. All tech and warranty support in Nevada. Quote
Sedalia Dave Posted November 20, 2025 Posted November 20, 2025 9 minutes ago, Chas B. Wolfson, SASS #11104 said: Nothing set in stone yet but this product is high on the list: 12V 300Ah MINI LiFePO4 Lithium Battery, Bluetooth Lithium Battery, 200A BMS, up to 15000 Cycles, Max.3840Wh Energy with Low Temp Cut off, Perfect for RV, Solar, Trolling Motor - 4Pack Visit the PUPVWMHB Store 4.6 4.6 out of 5 stars (180) | Search this page $1,236.00 with 7 percent savings -7% $1,236.00 List Price: $1,336.00 List Price: $1,336.00 Price history Or $56.61/mo (36 mo). Select from 3 plans Get a $250 Gift Card: Pay $986.00 $1,236.00 upon approval for Prime Visa. No annual fee. Delivery & Support Select to learn more Ships from Lifepo4 Battery - US Non-returnable. Transportation of this item is subject to hazardous materials regulation Customer Support Style: 12V300Ah - 4Pack 12V200AH Bluetooth $289.00 $289.00 12V300AH Bluetooth $309.00 with 11 percent savings $309.00 $349.00 12V300AH - 2Pack $618.00 with 7 percent savings $618.00 $668.00 12V300Ah - 4Pack $1,236.00 with 7 percent savings $1,236.00 $1,336.00 12V330AH Self Heating $389.00 $389.00 24V100AH $299.00 with 9 percent savings $299.00 $329.00 Brand PUPVWMHB Product Dimensions 13.58"D x 7.48"W x 9.64"H Terminal M8 Automotive Fit Type Universal Fit Manufacturer Vehicle Service Type ATV, Boat, Golf Cart, RV Voltage 12.8 Volts Battery Cell Composition Lithium-Phosphate Item Weight 59 Pounds About this item 【APP monitoring】Our lithium battery has listened to the suggestions of many users, so we have developed a special battery with communication function so that you can easily monitor the status of your battery in real time. This includes current, voltage, temperature, cycle, etc. Just download our APP to the phone according to the instructions. 【Advanced Technology】PUPVWMHB 12V battery is based on industry-leading technologies and manufactured using advanced industrial technologies. This model 300Ah LiFePO4 has excellent and reliable performance with sufficient battery capacity, the capacity of the monomer is still greater than 80% even after 2000 cycles. Lithium 12V can therefore be used immediately after charging, regardless of the charging status. 【Max. 61.44kWh Perfect for solar system】PUPVWMHB LiFePO4 battery 12V300Ah can be connected in series and parallel to achieve larger capacity (max. 1200Ah) and higher voltage (max. 51.2V). The max. Energy is 61.44kWh, the max. load power is 40.96 kW, which is easy for you to use anytime and anywhere, and makes LiFePO4 300Ah perfect for solar battery home system, stand-alone system, home power supply 【200A BMS & Safety & Environmental Friendliness】The stable chemical structure of lithium iron phosphate ensures that the LiFePO4 battery will not burn or explode even under high temperatures, short circuits, shocks and falls. Maximum safety based on the UL test certificate for the cell in the battery. And it contains no heavy metals and rare metals and is more environmentally friendly. 【5-year warranty】Since the lithium-ion battery contains no acid, you can safely mount it in any position. This makes Li-ion batteries perfect for boats, motorhomes, camper vans, caravans and off-grid applications! All PUPVWMHB batteries come with a five-year warranty. 24 hour friendly and professional › See more product details Note that several people complained that the dimensions are in accurate. Battery is 15.125" not 13.58" Quote
Texas Joker Posted November 20, 2025 Posted November 20, 2025 Look at will prowse on you tube. He explains, tears apart and tests all forms of batteries 2 Quote
Oak Ridge Regulator Posted November 21, 2025 Posted November 21, 2025 A couple of hints for your upcoming project. I have been off grid and grid tied for more than 35 years and ran my own solar business for 17 years specializing in off grid homes. I have worked with nickel iron, flooded lead acid, agm, gel cells, LiFe and LiPo battery banks. You’re making a good choice. Start off with a good name brand battery, stay away from the cheap batteries because you get what you pay for. If it has lithium in its chemical makeup it WILL burn under the right circumstances so keep an appropriate fire extinguisher handy. All these batteries have a BMS system which means there is basically a tiny computer in each one so getting cheap batteries means cheap components. Make sure when you get your batteries to charge each battery individually to full before you combine them in a bank, the BMS system needs to see the same state of charge in each battery from day one or the batteries will be out of sync. The battery heaters are a good option if you’re going to need to charge them in a cold environment but if it’s 50 and above they use up power. And one last tip….if you run the batteries flat you will have to jump start them with a battery of the same voltage before they will start charging again just like you jump start a car because the BMS has shut down and it won’t allow your charge controller to charge the battery. I saw a guy try to use a battery charger and it fried the BMS, not sure if every battery charger will do that or if he was using the wrong charger so I stick with a battery. your really going to love these batteries especially compared to lead acid ! Good luck and enjoy them 1 2 Quote
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