Not saying you are wrong my 20 amp smart charger takes a good 4 to 5 hours to charge my 150 amp battery at least and I do not let them get below 25% big no no I was told. I sure there is a difference between chargers just like solar panels might put out same charge just take's 5 to 6 times as long to charge. Lithium is love hate relationship for sure.My 20 amp lithium charger plug in charger charges my battery in about an hour. Why wouldn't a 20 amp solar charger charge it in 5 hours?