best gel charger and how to test a used one?

[woodygb]

The industry standard for battery capacity is calculated using 20 HOURS as the baseline ... I do not know the logic behind this decision.

Here is a graph showing a battery rated @ 51 Amp Hours ....So this means that it can supply 51 ( Amps ) divided by 20 ( Hrs ) = 2.55 Amps continuously for 20 hrs.

BUT the batteries Amp Hour capacity reduces if you take more than the 2.55 Amps given by the above calculation.

[Burgerman]

This only happens with lead batteries.

[yeshelp]

Ask if you dont understand any of it.

http://www.wheelchairdriver.com/MK1.pdf

What is C²⁰ please? In the top left of the table. (Sorry I can't make subscript with this keypad.) Always made me wonder, never held me back from learning how to charge my lead batteries.

hi i understand some of it other parts i dont ;

like the dod im not used to that concept even if i read the definition it is new
like i dont know how many cells are in a battery
likethe optional accelerated thing
and those 2 i dont get
:This step is generally unneeded if (1) zero load is present when device is not in operation, and (2) device duty cycle does not include periods of non-use exceeding 3 months.
To compensate for battery temperature not at 20°C, subtract 0.005 V/cell for each 1°C above 20°C; add 0.005 V/cell for each 1°C under 20°C.
Applies to East Penn’s 8G product line.


i fell like i understand more the big lines of max 30amp bulk charge wich stop when 2.3v per cell is reached .at wich point it is the beginning of absorbtion wich will last max12 hours or until o.1amp charging difference or less is reached comparing the end of an hour to its beginning.

[woodygb]

6 Cells in a 12v lead acid battery .... NOTE:- The battery is called 12v for convenience but it isn't... a 100% fully charged battery voltage is higher.

D.O.D. = Depth Of Discharge.....
Running the batteries until they are completely exhausted ( 100% D.O.D. ) is not good for them.... 80% is the recommended MAXIMUM.

[Burgerman]

i fell like i understand more the big lines of max 30amp bulk charge wich stop when 2.3v per cell is reached .at wich point it is the beginning of absorbtion wich will last max12 hours or until o.1amp charging difference or less is reached comparing the end of an hour to its beginning.

2.35V bulk ends. Called Constant Current stage since the charger is doing its max power. Trying to reach that 2.35v. Since 6 cells, thats 6x 2.35v = 14.1V per battery. And thats all you really need to know.

Accelerated finishing? Instead of waiting while the 14.1V charge at CV ends as the current falls to a super low value, or 8 to 12 hours at CV, you stop sooner. And then apply a CONSTANT CURRENT for X amount of time. This is all about speed. Its less accurate and less good for the battery. But say an airport floor scrubbing machine or fork lift truck or whatever has an overnight 8 hours only in order to get a full recharge then its faster...

FULL charge which is essential can be achieved 4 ways.

1. 2 stage charge, CC is first, where CV stage is continued for 8 to 12 hours/or current falls to 1500/1000thC at which point its charged 100%. This is the best way and almost the fastest.

2. 3 stage where the charger stops CV stage at say 1A or 2A or 3 to 5 hours, and then a float stage at a CV of 13.5V is used indefinitely. This takes around 60 to 24 hours to complete.

3. Float charge. Mostly used for almost full or full batteries to keep them 100% and if used in a deep cycle application would take around 36 hours to complete a charge...

4. Accelerated end. Same as 2 above. Except that instead of float a fixed low current (amps) is used for a specific short time period. This pushes the voltage higher and rapidly charges the slow last part of the charge. The current is choosen so that the gassing is within the levels that the internal recombination can cope... But this produces heat and shortens service life some. But if you need it charged faster than the normal methods you dont have an option.