any one use a battery tender?

[48ford]

Hi Guys,
any one use a battery tender?
with winter coming on I'm thinking of getting one.
Your thoughts?
Thanks Russ

[Crosley.In.AZ]

I have 3 in use on a regualr basis . I buy the Schumacher brand of tender from Wally World

[slocrow]

I use the ones from Habit Freight. They work swell, all Winter and when on sale are just $4.99.......

[Okiedokie]

I use a Battery Tender, and also use the cheap "float" chargers that Harbor Freight sells for $4.99 at times. The HF units seem to work as well as the other.

[Carnut]

I've used the HF, schumacher, and sears diehard which I think is a schumacher

Had 4 of the HF's and have replaced them with the sears diehard overtime.

Think I just like seeing the blinking lights on the diehard.

Actually I've got battery disconnects on 4 of mine and have frequently left off the tender with no problems over some times with the battery disconnected.

[32coupe]

Yep best thing I ever did for my battery

[Uncle Bob]

Yup, all you have to do is save one battery with it/them and they're more than paid for.

[wayne petty]

voltages to know how charged your battery actually

this test is done with the engine off..  turn on the headlights for one minute.. then turn them off.  this removes the slightly higher surface charge.


12.65 volts is 100% charge.
12.45 volts is 75% charge.
12.25 volts is 50% charge.


with a fully charged battery... when you start the engine.. you should have 14.1 to 14.7 volts depending on the brand of alternator..   if you have less and your battery tested close to full charge.. you have a charging system problem..

the voltage numbers are for MOST types of automotive battery..  there are a few special exotic designs with slightly different voltage charge amounts for testing.


battery tender voltage should be somewhere between 12.60 and 13 volts... probably not much higher than 13.0..  just so you know..

this will be on a fully charged battery...


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

bringing back a completely dead battery requires a current limiting adjustable power supply...   hooking that to the battery.. setting it to 0.5 amps short circuit current.. an 17 volts DC.. letting the battery sit for several days at this SLOW charge...  

if you have fast charged the battery or jumped it from another battery with this one dead.. you have probably ruined it...  but long term slow discharge or several days dead... DO NOT fast charge it.. it will harden the sulfate crystals inside and it will never work again..

just thought that everybody should know...

i learned the fixing deeply discharged batteries trick from a guy who worked in a commercial battery manufacturing company.. until somebody chipped through the 2 foot thick brick wall one weekend and stole everything in the entire building..  every battery.. every empty case.. every piece of lead plate...  the owner just gave up...

[rumrumm]

I use one as well. Using one is a good idea.

[Learpilot]

I got mine from Sears for under $25.00 , works great!
Rick

[48ford]

Thanks Guys,
I got a flyer today in the mail from the freight. There cost is 5.99 so I will give it a try.
later Russ

[Mac]

I got a cheapy tender off eBay. I take the batteries out of all 3 motorcycles and the riding mower I have, bring them in the (sometimes) heated shop and rotate the tender every couple of weeks.
Would you call me thrifty?   I betcha I saved a good $15 by buying only 1 charger and another $10-$15 a year on electrisical.
:oops:

[bowtietillidie]

I hope this is not highjacking a tread ........    If so I am sorry !!!!!
But I have a question .  Can anyone on this board tell me where I can buy a 6
volt battery tender.

[Carnut]

Both my schumachers and Diehards have a 6/12 switch.

[bowtietillidie]

Hey guys....... Thanks for the quick reply. There are three auto parts stores here in town and all three said they don't make 6 volt battery tenders.   Getting hard to find a good parts counterman.  Armed with the new information i can attack from a different direction .  Thanks again