Carl Ijames wrote:
I'm very happy with my Deltran Battery Tender Plus, had it 5-6 years now.
Smart charger that charges at 6A until battery voltage gets to a threshold
then charges at constant voltage until current drops to almost nothing to
finish charging the battery, then it floats at a lower voltage to maintain
full charge. The Jr model is 2A, the Plus is 6A max, available all over the
web for about $40. I think they were one of the first companies to offer
this type of battery maintainer but now lots of other brands offer the same
programming. No switches or meters, if those are important to you. I put
it on one battery for a few days or a week, then move it on to the next one
when I remember; never have to worry about overcharging.

I had a Deltran Battery Tender Jr, the 6-volt model. Bought new, it
never worked.

The green/red indicator lights always lied about what was going on.
Every time it was either doing nothing at all, or else actually draining
my battery, while the happy green light said it was charging.

The generous warranty period was pretty worthless. It had to be shipped
back to Florida, along with payment to Deltran for diagnosis, handling,
return shipping, etc. ... added up to much of the cost of just buying
another one.

After a year, I threw it in the trash. On the morning of trash pickup
day my Dad saw it in the bin at the curb, and brought it back. So I
smashed it real good with a hammer and threw it out again next week.