So I'm on my 4th battery in 7 years, the last one lasted only 18 months.

Obviously I talk with other UK H2 drivers and it seems to be a familiar story, batteries just don't seem to last.

Usually at 1st a new one is a joy, my radio stays on during cranking, but after a couple of months that is the 1st thing to go.

It's not always a daily drive, but it does go out a couple of times a week, usually further at weekends.

BTW the UK battery supplier is trying to duck-out the warranty, so no surprise there, the problem seems I've not been using it and it just needs charging

So is this normal, is there an inherent problem with Hummers or do I have a real issue?

It could be a little too much parasitic drain, though when the battery is new it can stand for a couple of weeks ( e.g. holidays) no problem, so no real evidence of a drain (only the radio is aftermarket)

It could be the alternator over/under charging or just a general OEM issue with charging, but for sure if I drop a new battery in it will be fine for at least a year+ so whatever it is, it subtle.

Batteries and charging is a complicated subject involving alternators, cranking amps, battery technology, load, shock & vibration, temperature, etc, etc and of course cost.

The last one was a 75A 800CCA side terminal, not easy to find over here and expensive, $180+ my previous one had both side and top terminals and lasted 3 years.

Currently looking at this one (note this link gives the specs which look good, I can get it for around $345) it should fit and is dual terminal.

It would be very interesting to get your collective feedback/views on this...

(What on earth does a Hummer EV battery cost? )

 

You have fully disconnected all of the Onstar stuff right? I'd even go as far as to make sure the modules in the dash are unplugged in addition to the VCIM fuse. Of course unless yours was upgraded to the newer digital Onstar and you actually use that in which case you might want to keep it. I have a couple of vehicles that are infrequent use but they stay outdoors. On those I bought a solar battery maintainer that plugs into the cig lighter socket (has to be one that is always powered) that sits on the dash and keeps a decent trickle charge going.

Other options are permanent install a trickle charger and keep that plugged in when you are not using it. The last battery I had in my 03 H2 was over 5 years old and still going but in the last year it had gotten to where it was quite sluggish starting if I had not run it in more than a week (but would still start it and be fine once I drove it some). I've seen others add a battery disconnect but the pits there is of course most all memory functions get lost like in the radio.

Another I might check, if I remember right, your has an aftermarket propane setup, would be to check that nothing in that setup is constantly drawing power when off.

Of course a parasitic draw test might find things as well which you are of course quite capable of with your electronics background.

On battery longevity though. That does vary by brand. I know here there are dozens of brands of batteries but realistically they all are made at about 4 different places and are just labelled different. They are expensive here as well. I typically get at least 3 years or more out of a battery. I do also tend to go for the premium versions though as those have better warranties but also supposedly use thicker plates internally. Most places here will have the same battery in 2 or 3 "levels", economy, standard, and premium.

I did try one of the newer AGM type batteries many places offer these days in a pickup we had. It lasted about 18 months - rubbish. I think the charging system in a vehicle is not really proper for the AGM batteries and I've heard many stories of people trying them and going back to a traditional flooded or gel type battery. AGM batteries require a different voltage for proper charging - probably why many of the chargers these days have a specific setting just for an AGM battery, yet vehicles do not.

 

Thanks MixManSC you're always on the ball...

There's no Onstar coverage here in the UK, so was never fitted for genuine GM imports.

BTW would that be the "INFO" fuse under the hood, it seems to the one on the 04 wiring diagram.

The solar charger is a great idea, I'll look into that. I have a friend with a "disconnect" like you say the radio needs re-programming afterward which seems crazy in this modern world. Why radios can't record either is beyond me.

The aftermarket LPG is another good point, however I'm not aware that it runs with the ignition-off, certainly no activity on it's little key pad, I'll look at that too.

Looking into it, your comment about AGM seems well founded, that one I listed is AGM and despite their data-sheet, other info sources advise against for the same reasons you quoted.

One idea I have is to get some "side-terminal to top-post converters" which opens-up more market possibilities/options, for example BOSCH over here has a good reputation, some investigation is called for I think.

I get the feeling 18 months is bad, 3 years OK sort-of, 5 years+ would be good.

Good job I asked the question, in the meantime I've put my old battery charging on repair-recovery-mode nothing to loose I guess. Just looking for converters, not so common over here.

Thanks again MixManSC !!

 

DISCHARGED BATTERY SHORTENS THE LIFE OF THE BATTERY!
Monitor the voltage. Keep in mind short trips does not fully charge the battery. I use a cheap

LED Digital Voltmeter

LED Digital Voltmeter

that plugs into the cigarette lighter to monitor voltage. When the volts dip low, I connect the battery charger and give it a few hours on a 2amp charge.



Car Batteries Are Made to Die

Why Is Discharging a Car Battery Too Far So Bad?

Even though 80 percent of the capacity remains when a car battery dips to around 10.5 volts, the battery is considered to be fully discharged because taking the cycle any deeper will cause irreversible damage to the plates through excessive sulfation.

While normal sulfation is reversible, excessively draining a battery, or leaving it in a state of discharge, will allow the soft lead sulfate to crystallize. At that point, charging the battery will still cause some of the sulfation to reverse, but any crystallized lead sulfate will remain on the plates. This sulfate cannot, under normal circumstances, return to a solution in the electrolyte, which permanently reduces the available output of the battery.

The other detrimental effect of allowing crystallized lead sulfate to form is that it effectively shortens the lifespan of the battery in an empirically measurable way. If too much of this crystallization is allowed to occur, the battery will no longer be able to provide enough amperage to start the engine, and it will have to be replaced.

 

Thanks hummerz , actually I have one of those, pretty much the 1st thing accessory I ever bought, funny thing was I thought it might be that draining my battery.

Of course I'm aware of sulfation (more than this forum spell-checker for sure) but the truck never gets left idle that long, no more than any other of my vehicles.

I have battery booster-pack (which is truly amazing) which I keep in the truck for emergencies, it's rescued me many times.

Actually I designed battery monitoring systems and power supplies for my last client, so I'm familiar with discharge/charging rates etc, it just seems the Hummer is battery sensitive.

For example I have a VW Golf TDI which I use less often, probably 10% these days, sometimes it's been left for a couple of months, it always starts, never hard to charge it.

I'll get to the bottom of it, I'll run through the GM parasitic Load tests again and see where the mA are (no more than 25mA if memory serves) but I think we've all been there in the past.

 

 

Interesting technique, good for narrowing it down, makes a lot of sense, neatly demonstrates how fuses work.

Thanks for that!

 

Hey Buddy. So I live in the same climate as you @oceanbrave .

My OEM battery was changed after 10 years, not because it was dead, but because I was sure it would go dead soon.
I bought another OEM battery, and now with the vehicle 15 years old, that battery is 5 years old. I expect to get another 5 years out of her.
I do not have an aftermarket stuff on the car, except for a 2nd high-mounted backup camera, that displays thru the NAV screen.
In addition to the OEM slide-out-camera integrated into the mirror (which I never use).

I normally expect to get 7 years out of a GM battery. Or an Optima red-top. Or other AGM.
Battery manufacturers are not in the business of giving away $$ on warranty claims.
So the battery should normally last just bit longer than the warranty period.

If you rig is eating batteries, there is something wrong with the brand or the truck. Definitely not normal.
And every other GM vehicle (many, over decades) we have owned got at least 6 years off a GM battery, or any other quality battery like an Optima. So this is not isolated to a battery series (size).

Don't you have a GM/Opel/whatever/Delco dealer in the UK, that can get you a proper GM branded battery?
At this point, if you eliminate any issues with the truck, the high cost of a GM battery could be worth the peace of mind. (and save money on tows or boosts).

Someone must be shipping all of the batteries that do not pass Quality Control to the UK :0

Cheers.

 

Are you getting the proper group 79 sized battery? a group 78 is a bit smaller and more common in parts stores. I have had great luck with AGM batteries, but lately it seems batteries have not lasted as long as before, instead of 4-5 years, I see batteries lasting 2-3 years. I think any battery over 3 years old could shoot craps at any time.

 

the battery in my 03 has read 11.9 volts standing for 4 years the battery is from 2014. starts perfectly fine no slow cranks. my digital autel battery tester states it still has 74% health left in it. my cigarette lighter voltmeter/BT interface states with engine running the voltage is at 14.3