transformer vs charger

[lars56ca]

I picked up a small transformer style charger for a 12V 7aH battery that I have. It's rated for 12V 1A. After looking at it, I started wondering what the difference would be (if any)between a charger and a transformer, aside from the wire and alligators clips

[ady]

Zip

All chargers require a transformer to bring the 110 down to a useable level then a voltage rectifier/regulator to turn the ac current to dc. Then the difference comes for different chargers, the more expensive ones monitor and change the current for better charging and can also supply more than 1 amp. Cheap ones just turn off when the current draw drops to a predefined level. Google away and look at the different chargers and battery types, you need to understand this stuff to maintain your battery and get maximum performance out of it. There have been many good posts on this topic over the last few years.

[mikemicropterus]

Imagine a charger as a device that PUSHES electrons(amperage) into a battery. This pushing of electrons causes the plates to corrode and that produces electricity. If the charger is stupid it will keep trying to push electrons into the battery. This increases temp and causes the fluid in a lead/acid battery to boil and evaporate. Continued use of this kind of charger will deplete the electrolyte and cause the plate to be exposed and the battrey will lose it capaciyt very quickly.

Smart chargers monitor the push and when it falls below 1 amp the charger shuts off and just tops off the charge when needed.

Ady is correct when he says the charger has a transformer which take the 120 vac to 12vac and the rectifier changes the ac to dc, the regulator keeps the amperage at a level to charge the battery.

A deep cycle battery needs to be charged at a max of 10 amps for whatever time it takes to fully recharge the battery.
A starting battery can take up 50 amps or more when being charged and the battery can accept that amperage. A deep cycle being charged at 50 amps will overheat quickly and the heat can distort and then short the plates, leaving that cell dead.

Your tansformer is just stepping down the voltage(transforming) and not changing it to dc so it will not charge the battery and if the battery was half charged a 1 amp charger not transformer will not have enough PUSH to overcome the existing charge. Thats how chargers work by overcoming resistance of the static charge in the battery.

Rule of thumb, If you use the battery for 5 hrs it will take that long to recharge it. 2hrs use 2hrs charging 3 hrs use 3hrs charging etc