House Battery Not Holding Charge , Bad Battery or Converter Issue?

Perfect time to move to a Lithium battery. If you are a senior you may never need a replacement and the new “compact” Lithiums are super small. My son in law had to lift out my old Trojan T125s but I sent him home and installed the Lithium alone and easily in 2023. No water fills, no cleaning, no gas etc. 

Yeah, a battery that won’t hold a charge is a dead battery. If you really want confirmation, take it to the nearest AutoZone/Advance Auto/O’Reilly’s and ask them to test it. Bet it fails.

So whatever you do, do not waste money on one of those 70-80 Amp Hour “marine” batteries. Lead/acid batteries have a lifespan of 300-500 charge cycles, max, and that assumes you discharge it only 50%. Currently (as of the date this is being written) the way to go is to buy the best built and cheapest LiFePO4 battery on the market which I am seeing for $549 online via Amazon or the WattCycle store: the 314 Amp Hour Mini. Cheaper, but lesser quality, $339 for the Dumfume 300 Amp Hour (rated 4,000 charge cycles). Will Prowse has tested both batteries and torn them apart to examine quality of construction, and he recommends them for those applications needing 12 volts. The WattCycle battery is rated for 6,000 charge cycles, should be charged to 100% capacity and can be drained to 20% (for that max life) which will give you 18 years of daily cycling between 20-100%. You can drain it to only 10% and you will still get lifetime service out of it.

Charging your phone doesnt make a drop of difference on a wet RV battery or Lithium. 

benjaminfoster​ been smoking a little too much of the devils lettuce and can’t function any bette than his chitty Walmart lawnmower battery in his camper I think!

what kind of battery and how many, have you run it down to where the lights started dimming befor and how many times, and how old is the battery?  

all good info to include for this kind of situation

Typically a battery that won't hold a charge is a bad battery, either from age or being discharged so low the capacity is diminished. But yeah, you'll have to have it tested. 

You just asked the same question twice. Save a little power from charging your phone by not repairing yourself?

You really need to get a battery tester to start, it's more than just voltage, need to check on a load and see what the condition of the batteries are...