Changes

Gels and AGMs have a lower internal resistance, losing only 1-3% per month due to internal discharge. Gel cells lose 10-16% to heat during charging while AGMs lose as little as 4%, meaning that the charging system can be smaller.

All of these types are built in different physical sizes. The most appropriate size for a boat’s starter and house banks is 8D. Types cannot be mixed in a house bank, because they have different discharge and charging rates. In fact, all batteries in any battery bank (not just on a boat) should be of the same brand, type and size and, preferably, batch number. [http://lifelinebatteries.com/ Lifeline], [https://www.optimabatteries.com/ Optima®] and [http://rollsbattery.com/ Rolls Surrette] are typical AGM brands.

Lead battery lifespan is reduced at temperatures over 77 °F (25 °C), so put the batteries low and as close to the keel as possible to keep them cool. It is a good practice to have the house bank fused internally as well as externally. This will keep a battery gone bad from shorting and discharging the entire bank. Some batteries are built so you can replace individual cells.

== References ==