I finally got my battery pack and charger for my Pool Blaster. The old one died and it turns out part of the problem is the wall wart charger ends up overcharging the NiMH batteries. Anyway, rather than deal with Watertech and buy a flawed system again I decided to look for an alternative.
What I got was a 5000MAH capacity battery, which is double the capacity of the original. I also got a smart charger that shuts off when the battery is fully charged which takes about 5 hours. I had to do some soldering because I ordered the wrong ends but it works perfectly. So twice the capacity and a better charger for a few bucks more (~$70). Makes sense to me.
I asked the owner of the company if he would manufacture a plug and play kit for TFP members and offer a 10% discount. I asked for this and have no idea if it infringes on the site policies so that's all I'll say about it now. Suffice it to say if its OK I'll work on getting a link set up if anyone is interested. I have no affiliation with this person and will gain nothing but he was the one who manufactured it for me so I thought I'd ask.
Here are some pictures. The install is a joke with a single phillips screwdriver.
Comparison between new battery on left to old battery on right
Battery installed in Pool Blaster
and the charger,