If you are looking at the first one, it has an automatic charge setting and can charge up to 3 amps depending on the packs ability to take currant. I do not trust the packs enough to use a auto detect and set currant. Too easy for something to go wrong and cook a battery. Try scrounging up the cash to get the GP Poly charge 4 or an equal brand to be able to set charge currant while doing multiple packs. Along with one balancer with adapter plugs for the batteries you have, for the occasional rebalancing needed.
You will be buying a charger like it before very long anyway so bite the bullet now and not have to do it twice.