Originally Posted by Caffeinated
.... For the longest time, Airstream installed single stage chargers in the trailers. Those single stage chargers charged the batteries with a high voltage, which is great whe the batteries were run down, but not so great when the batteries were closer to fully charged......
Sorry but this just bugs me:
A single stage charger would have only operating mode (a single stage). A two three or four stage charger has two three or four operating modes.
So if it has only a single mode, that would have to be fixed voltage at infinite available current or constant current at infinite available voltage. Both are impossible.
A normal two stage charger starts out at a limited current and maintains that current to a fixed voltage point. It has a spec on it like "55 amp charger". If you look at the spec sheet on any charger in any RV I've ever seen, it's got a current number on it.
Bottom line is that even the most basic charger you would ever buy is a "two stage charger". You can look at the descriptions on three and four (five ... six ...) stage chargers, the first two stages are always the same. If we are going to talk about three or four stage chargers, then we need to at least talk about all the devices in the same way.
Note that this is completely independent of the debate over the value of the third stage on the current crop of stock chargers ....