Originally Posted By: 1 FMF
be careful with the harbor freight $5 float chargers,
I've bought a few over the years and 50% of them were dead out of the box, you wouldn't know it unless you used them on a good battery and used a volt meter to make sure they held at 13v or higher.
I bought three of them. Not sure why, but it was a $5 coupon special. They were also all different, with different part numbers, different packaging (plastic vs cardboard), and different power supplies. The box regulating the output seemed to be the common part. I think those are also extremely weak - maybe a 0.6A output and probably not something complex like a pulse charge. They say don't hook it up except for a known fully charged battery.
You can use something like a Schumacher 1.5A maintainer to charge a battery. The older ones don't care, but I heard the newer ones (like mine) will time out if it doesn't reach green after 24 hours or some other set time. I do prefer my SpeedCharge SC-1200. I'll just set it to 3A and leave it there until it's done.