Which lithium trolling motor battery should you buy?

A trolling motor pulls continuous current for hours, not the short bursts a solar or RV battery sees, so the battery management system inside a motor-duty pack is sized for sustained high draw and states a continuous discharge rating in amps. A general purpose LiFePO4 battery of the same amp hour rating frequently does not publish that figure at all, because its BMS was never built to be asked for it.

Yes. A lead acid charge profile either never reaches the bulk voltage a LiFePO4 pack needs to fill fully, or it holds the pack at a float voltage lithium cells should not sit at for long. A charger with a selectable lithium profile, like the Minn Kota PCL series or a NOCO GEN model with a 12V Lithium setting, solves this with one menu choice and is worth buying before the battery rather than after.

Neither brand sells its trolling motor batteries through Amazon listings that can be verified as genuine. Searching either name returns a lookalike battery whose own product title says it is compatible with Battle Born, which is a clone advertising itself against the real brand rather than the real brand's own listing. Carding that clone as though it were genuine would be worse than simply saying the gap exists.

Often, but check the specific model rather than assuming. LiTime sells the same 100Ah cell in a Group 24 case, a Group 27 case and a compact Xtra Mini footprint specifically so it drops into a tray built for lead acid without a rebuild. A generic lithium pack sized for maximum energy density rather than a standard case will not always match, so the case dimensions on the listing matter as much as the amp hour rating.

The published weights make the case better than any marketing line. The LiTime 12V 100Ah Xtra Mini weighs 19.13 lb with handles, while the VMAX MR137-120, a 120Ah Group 31 AGM, publishes a weight of 75 lb. That is more than triple the weight for a similar amp hour rating, and moving that much weight out of the bow changes trim and handling on a small boat far more than the price difference suggests.

No. Charging voltages, profiles and how each chemistry behaves near empty are different enough that mixing them in one bank charges one chemistry wrong no matter how the charger is set. A separate bank, a separate charger output, or a full switch to lithium across the whole system is the workable path, and a multi-bank charger with independent per-bank profiles is what makes a mixed boat practical during the changeover.