How to jump-start with two 24V batteries?

[JakeAnn]

Connect positive to positive and negative to negative, but note that this refers to the terminals after two batteries are connected in series to form 24V. Do not connect to a single battery. Below is relevant information: 1. Connection sequence purpose: During overcharging, lead-acid batteries may produce flammable hydrogen gas through water electrolysis inside the battery. Jump-start procedures are usually described in the vehicle's manual. The recommended connection sequence aims to reduce the chance of accidentally short-circuiting the good battery or igniting hydrogen gas. The user manual should indicate the preferred locations for jumper cable connections. 2. Battery lifespan: Car batteries typically last 3-5 years, depending on usage. Power consumption increases significantly if you frequently use air conditioning, play music/videos without starting the engine, or forget to turn off headlights.