I bought two 100s and two 50s to replace four group 27 100ah SLAs. Total weight reduction from 270 to 80 (including on-board chargers). SLAs were placed fore and aft to balance weight distribution. Now all four in back end of boat with no problem. First test drive of 2+ hours constant movement, and both trolling motors still showed all 4 lights (meaning "fully charged"). Back home 4 5-amp chargers had completely restored to 100% within 2 hours. The 50s are to run 2 Helix displays and MegaLive - separate to prevent crossover with side imaging sonar.