<VV> Re: Battery Tenders

[FrankCB at aol.com]

I use a Deltran "Battery Tender Plus" (a thoughtful  gift from son Jim) which 
is in the $50+ price range.  It has 3 rates of  charge and switches 
automatically from the 1.25 amp max rate, through the  intermediate rate to the final 
float rate as indicated on the LED lights.   This unit enabled my original 
Delco "Dustbuster" battery to last 11-1/2 years  before I had to replace it.  I 
use it regularly on all my cars, especially  the Corvair that sits in the garage 
for many months at a time.
    The secret to any "float charger" is that is should  maintain a 13.5 volt 
charge on the battery which is high enough to keep it from  deteriorating and 
yet not so high that it causes overcharging and loss of  electrolyte.  Even a 
good lead acid battery will lose about 10%  of its charge per month if left 
off a charger.  And if it stays too long at  a low charge, the plates will 
sulfate and the battery will then refuse to take a  full charge.
    Frank "likes BIG batteries" Burkhard
       
In a message dated 1/19/2007 1:28:12 AM Eastern Standard Time,  
slowboat at mindspring.com writes:

You're  correct about the name "battery tender", but it seems like it's
becoming  the generic name for these devices. Sorta like "Hoover" applies to
all  vacuum cleaners. Anyway, I have one of the Sears Craftsman devices,  and
curiously enough, it looks identical, except for the labels, to the  last
$19.95 one I recently bought at Harbor Freight. They're both made in  China,
and seem to work really well.
Also, I had a couple of responses  regarding how long is "long term" storage.
Personally,
when my show cars  or infrequent drivers are not being used, they sit with
"battery tenders"  (float chargers) attached. That's just me, I suppose,  but
batteries
definitely last longer if kept at float voltage during  dormant periods.
I do the same with the boat, because golf-cart house and  8D start batteries
are expensive to replace (not to mention the strain on  my back getting them
out of the engine room!), so I take extra good care of  them. 12 years and
counting on these, so far. The boat charger is what they  call a "smart
charger". That is, it provides a bulk charge to a depleted  battery and then
switches to "float" when the batt is fully charged. These  are a bit
expensive to have one for each car, though, and probably overkill  in that
application as well.
As always, YMMV
Andy  Clark