Stress-resistant battery has a casing (10) with compartmental walls (21 - 25) partitioning electrochemical cells each having interleaved negative and positive plates and a cover (40) with a bottom portion fitting into the casing including cover bosses (80), integral with, and protruding from, its inner bottom portion. Baffles (34) snap fit into the inner bottom portion (43) of the cover and make an interference fit with the electrochemical cells when the cover is fitted to the casing. Cast-on straps (90), each including a seating boss (91) connecting with one of the cover bosses, are welded back to back in pairs through each of the compartmental walls so as to form an electrical connection in series from one electrochemical cell to the next. A positive terminal connector (82) has a threaded elongate end extending out over the cover to make electrical connection with one side of the load and a platform attachment means at the other end welded to a positive plate group. A negative terminal connector (85) has a threaded elongate end extending out of the cover to make electrical connection to the other side of the load and a platform attachment means welded to a negative plate group.    Also claimed is a method of constructing a stress-resistant battery as claimed above.    USE -   Battery is intended for use in motor-cycles, jet skis, and other small recreational vehicles where resistance to vibration and mechanical stress is needed without increasing battery size or weight or degrading battery performance.    ADVANTAGES -   Relatively inexpensive, light and solvent resistance materials are used to construct the battery but a relatively greater number of positive and negative plates can be packed per electrochemical cell. The large plate density improves output voltages and currents and provides longer periods of peak voltage delivery to a load in comparison to other batteries of equal size and weight. External vibrational stresses are reduced by using both external casing reinforcements and a novel cover assembly design. Internal vibrational stresses are reduced by novel cover assembly and plate strap designs.