The batteries are all similar except in two areas.
One is simple and that is the amount of energy they contain. On all the batteries you will see something like 2000mah or 2200mah. This means that over a period of an hour one battery can give you 2000 miliamps of power and the other can give you 2200. Higher number is more. If you are sitting at home and run out of juice you can pop the battery on the charger and put the next one in, you should have at least 2. However, if you are out and need just that little bit to get you home the 2200 would probably be the better choice.
The second is a little more complex, and with the 134 simpler. That is the amount of current that the battery will deliver. If you have a mechanical mod, nothing more than a tube with a switch, it is possible, easy if you do not pay attention, to ask a battery to deliver more current than it can. The battery does not like this and will try to hurt you by expelling hot gas.
The 134 is a regulated mod and that means that the electricity from get battery goes through an electronic circuit. In the case of the 134 the circuit will stop you form doing bad things to the battery. It will never ask for more than 5 amps and if it breaks there is a 7 amp fuse. I don't know of a battery that will not handle that.
If you do get into mechanicals or high wattage regulated mods you will need to find information from the manufacturer about how much current a battery can provide, but that is a problem for your future.
PS one more thing the 134 will do is turn off when the battery runs down. If you keep using a battery after it has run down it will hurt the battery and the battery will not hold as much energy as when new and you will end up having to replace it. Regulated mods also look out for you here.
