Regarding chargers, we have several.
We have this charger from Deltran
http://www.batterytender.com/Charger...er-12V-2A.html
Also if you get a Deltran, search online. The street price is about 500 bucks, much less than list price.
Using this Deltran charger has given us stunningly good results in maintaining batteries in a very good fashion and maintaining a long life. The 2 AMP charge rate is ideal for the types of 18AH batteries we use. Frankly I think it is the best and works great for competition if you have enough batteries to manage the longer charge time.
Our other battery support system is essentially identical to the one
here except we use a different battery charger.
This is the charger that we use
It has a 5 AMP peak charge rate. I don't have scientific evidence but my feeling is that the 2 AMP Deltran is much better at helping the batteries live a long life. The reason we have this system ( 14 chargers @ 5 AMPS ) is to support 8+ hour long multi-robot public demos. It is hard on robots and batteries.
A picture of the system is
here.
It has been updated to have a mid-rail plug mounting system like Team 900's.
As for the Schumacher chargers - I just don't like them, at all.
One more time - we REALLY like how the 2 AMP Deltran takes care of batteries.