I have an '06..29K miles..original battery..Cable ends have been changed. The truck gets driven about once a month. I keep a Deltran battery tender on it.. I drove it yesterday..about 80 miles..Back in the garage..hooked up the tender...This afternoon I noticed the green charging light was flashing..but the red light was still on..Only thing I can think of is the battery is on it's last legs..Any thoughts from the experts ?..Thanks...JV..

 

before starting my batt reads under 12v and drops a little on crank. then goes to 15 volts for a while, then drops down to 13-14? from memory!
unhook the tender, measure to see how yours does. drive a while and let it sit an hour and repeat without the charger. see what happens.
it usually goes to 15 for a while,few minutes.
see how far it drops when sitting for an hour. around 12v is ok. it should start without the tender.

 

hmmm... That battery is about 9 years old, that could be your problem.

 

As a precaution, I put the Deltran that I keep on my 450SL on the H3 last night. I had one of these tenders fail after 2 years.. This morning it showed a full charge...but it took 36 hours to do it. My first thought was to replace the battery..which I will do today. It is old...and the aggravation of my wife calling from her favorite Mall...(60 miles away) is not worth the gamble. Think I'll get an Optima. I have a red top in my F-150..NEVER a problem...Thank you for your comments...jv..

 

Can someone tell me the exact Optima RedTop battery that an '06 H3 takes..Optima site does not list one..Local Oreillys doesn't know..thanks..jv..

 

First, I no longer use Optimas as I have had for chit experiences with 3 of them now. One leaked, one bit the dust from a shorted cell, and the other lasted no longer than a cheap no brand.

Next, they do not list one for the H3 because the do not fit without modification to your battery box. https://www.hummerforums.com/forum/h...install-23485/

 

Get an Ever Start Maxx size 86 at Wally world.

$115 3 years free replacement...

 

Never been an Optima fan.

We went with old school style rectangle batteries but upgraded to AGMs and haven't had a single issue since. Higher CCA, great reserve capacity for winches and other accessories), much better for rigs that get wheeled (no plates to crack or dislodge) and excellent for vehicles not driven everyday.

 

AGM is the way to go.. soon that will be the only battery available..

East Penn Deka battery is the way to go.. The ONLY American made battery out there and they have been around for a long time.. They sell batteries under different names, Including the Sears DIEHARD(within the last 2 years). You wont find their battery at WALLYWORLD NOR AUTOZONE, however many other auto parts stores carry the DEKA made battery including NAPA.

Don't be cheap on the battery, as it is wayyyyyyyyyy to important and a defective battery can cause alot of damage. GL

http://eastpennmanufacturing.us/default.aspx?pageid=4

 

every diehard i had "died hard " in about 35 months. i dumped them 25+ yrs ago. no more.
i had one off brand batt replaced since then.
wally is fine with me, the biggest one that fits in!