Changes

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.

All of the above types are available in flooded or sealed sub-types. Flooded batteries are an older design. Internally they emit oxygen from the positive electrode and hydrogen from the negative one. This has to be vented to the outside to release pressure, i.e., they lose water and you have to top them up regularly. They have a relatively high internal resistance, which causes them to lose their charge by as much as 1% per day. During charging, they can lose 15-20% in heat losses.

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.

[[Category:BatteriesGeneral]]