New j.d. Powers reliability study

[kn5owa]

New study shows Lexus and Porsche are tops on reliability with Hyundai not doing too bad.

But what's interesting is that battery failure is a major reported problem - and has had considerable posts on this forum.

Battery failure on new luxury cars? Sounds like a throwback to the fifties when we had generators, mechanical voltage regulators, lousy tires, and yes - battery problems.

 

[Mark_888]

Battery problems are often a symptom of an underlying electrical problem with the car, where the battery is drained even when the car is shut off. Based on feedback on this forum, battery problems seem to occur more often on models loaded with electrical features, and less so on trims with fewer such features.

 

[Ragnar]

Well that's jus' Great!!😂

 

[linmk2]

RE: Battery Problems. I worked for many years in auto dealerships. Batteries were always going dead. The worst seemed to be the Acura. We had to replace many under warranty. In 1976 I bought a brand new Ford Thunderbird. When it was less than a week old, I opened the door to drive home from work (a Ford Lincoln-Mercury dealership), the interior lights turned on as they should, put the key in the ignition, turned the key and BAM! The battery exploded! The whole top of the battery was in pieces under the hood. Luckily, there was no exterior paint damage. So far, I've not had any battery or any other problems with the Genesis. I've had it about a year and a half, 16675 miles.

 

[Aquineas]

Wow, battery issues. I wouldn't have expected that.

 

[Ragnar]

It is amazing that after all the advances made in the automotive industry that we're still using the same old lead acid batteries in our we had in the 1930/40s cars,and yes they will on occasion explode on startup!!

 

[silberma]

The battery in the trunk of my Genesis looks like the AGM battery in my BMW. It should last longer but be expensive to replace

 

[kn5owa]

The battery in the trunk of my Genesis looks like the AGM battery in my BMW. It should last longer but be expensive to replace

I think it is an agm battery - the owner's manual doesnt say. But, it looks like a backbreaker to replace - as well as expensive

 

[Midnightsun]

Have a similar one in the trunk of the the Mercedes SL. AGM, big, heavy and around $250+. So far mine is a non issue going on 3 years however right now it is on a shelf stored for another month or so on a maintenance charger. In the past it has sat at airport parking for up to 3 weeks with no starting issues upon my return. Must have gotten a good one.

 

[Mark_888]

You can get a H8 AGM battery from Advance Auto Parts or AutoZone for about $185. With frequent online discounts (order online and pick up at store) you can usually get at least 20% off. Both batteries are made by Johnson Controls (who also makes Interstate Batteries). Walmart also sells a similar battery made by Johnson Controls, but not many Walmart stores carry the H8 AGM model.

I got the regular H8 Gold battery (non-AGM) for about $30 less, because it had a better warranty. There is a lot of controversy as to whether regular maintenance free batteries or AGM batteries will last longer, depending on conditions and discharge frequency. However, if one has a Tech Package or above trim level, I would go with the AGM. Both are lead acid, but the AGM holds the acid in absorbed glass mat cells, and the regular ones are "flooded" cells. One big advantage of AGM is that they can be turned upside down and still not leak or have any degradation of performance. So if one lives or drives where there are steep hills or very bumpy roads, AGM is definitely the way to go.

There are videos on YouTube that show how replace the Genesis battery. The H8 battery is heavy, but not that hard to handle since they have handles on them.

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[Seejay]

I did a little digging on the net, and found a lawnmower/tractor forum that had a large thread on AGM batteries. Low-usage and maintenance storage are the issues for them, of course. One contributor stated he changed a lot of AGM batteries for BMW cars as a tech, but other contributors found great reliability in their lawn tractors.

http://www.tractorbynet.com/forums/parts-repairs/359309-agm-battery-life-expectancy.html
and
http://batteryuniversity.com/learn/article/absorbent_glass_mat_agm

One of the things I found out was that current and voltage should be monitored for charging, so a modern charger designed for AGM should be used for maintenance, but is not a requirement. Maintenance charging higher than 14 VDC for a 12V AGM battery should be avoided, and discharges greater than 60% as well. AGMs are now being used in stop/start vehicles and are recommended for cars like the Genesis. That means the annoying message on the display when we are playing the radio during a driveway moment about discharging the battery is sort of stupid if the battery is fairly new. AGMs are supposed to last longer than standard lead acid batteries.

I think Hyundai cut corners or chose a bad vendor here. It is either the environment (some wiring issue or misapplication, like a wrongly specified voltage regulator on the charging system, or some component drawing too much power while the car is parked, etc.) OR it is a bad battery. Since we are starting to get contributors telling us that their batteries are dying at the two year mark, I think the OEM batteries on our cars are crap and amazingly over-priced. Time will tell.

 

[kn5owa]

As a point of interest - my owner's manual tells how to maintain agm batteries (p. 7-42) but does not specify what is actually used.

My pdf shop manual does, however, specify an agm battery complete with photo and specs.

 

[glennk]

When changing the battery, are settings lost? Is there any way to avoid this?

 

[Midnightsun]

Food for thought. Careful on what you choose. Trunk batteries are normally AGM as no venting is required. If you replace an AGM with a wet cell then you need to figure out how you will get a vent line to the outside. That being said, older vehicles do have a vent line present so not an issue in those. May be a moot point as I do not know if there is a vent line on the Gen 1 or 2.

 

[kn5owa]

When changing the battery, are settings lost? Is there any way to avoid this?

Easy on the G2 - connect a 12 volt power source to the "under the hood" front terminals - a small 12 volt storage battery would do the job. Also, a 9 volt dry cell battery would probably work. Then swap out the main battery in the trunk - may need a back brace there, though.

They also sell gadgets to keep the computer/car settings memorized - check ebay/amazon ***. Ebay has a raft of gadgets that plug into the OBD port. But a 9 volt dry cell and some clip leads would be cheaper, easier - esp. with the available terminals easily accessible under the hood. I think some of the commercial gadgets actually use a 9 volt batt.


*** search on "auto memory saver" if you insist on spending money.

 

[Mark_888]

Food for thought. Careful on what you choose. Trunk batteries are normally AGM as no venting is required. If you replace an AGM with a wet cell then you need to figure out how you will get a vent line to the outside. That being said, older vehicles do have a vent line present so not an issue in those. May be a moot point as I do not know if there is a vent line on the Gen 1 or 2.

There is definitely a vent line for the Gen 1.

One aspect about venting that many don't know is that most batteries that need venting have vent holes on both sides (to fit various cars) and one of the holes has to be plugged, while the other takes the vent tube. Batteries like that should come with a vent plug that is molded into one of the plastic covers that hides the terminals before installation.

 

[lobsenza]

I thought all trunk mount batteries need venting via tubes. Do AGM batteries not need venting?

 

[Seejay]

I thought all trunk mount batteries need venting via tubes. Do AGM batteries not need venting?

A standard lead acid battery produces and releases hydrogen gas when it is being charged.
In normal operation, an AGM battery does not produce hydrogen gas. Like most trunk-mounted AGM battery equipped vehicles, I am pretty sure the Genesis has an emergency vent tube for the battery. Most automotive AGM batteries have a "popoff" pressure relief valve that should be connected to the tube. If pressure builds up in the case, the valve opens and vents hydrogen gas through the tube.

 

[Ragnar]

When changing the battery, are settings lost? Is there any way to avoid this?

When we installed my lighted door sills we disconnected the battery for 1 1/2 hours and after reconnecting found we had lost no settings either to the audio or navigation. Suprised and pleased at that!!

 

[Mark_888]

A standard lead acid battery produces and releases hydrogen gas when it is being charged.
In normal operation, an AGM battery does not produce hydrogen gas. Like most trunk-mounted AGM battery equipped vehicles, I am pretty sure the Genesis has an emergency vent tube for the battery. Most automotive AGM batteries have a "popoff" pressure relief valve that should be connected to the tube. If pressure builds up in the case, the valve opens and vents hydrogen gas through the tube.

I don't claim to be an expert on batteries, but after doing some research I believe that AGM batteries are lead acid also. Here are a couple of quotes I found (at two different sites):

"AGM batteries differ from flooded lead acid batteries in that the electrolyte is held in the glass mats, as opposed to freely flooding the plates. Very thin glass fibers are woven into a mat to increase surface area enough to hold sufficient electrolyte on the cells for their lifetime."​

"AGM technology became popular in the early 1980s as a sealed lead acid battery for military aircraft, vehicles and UPS to reduce weight and improve reliability. The sulfuric acid is absorbed by a very fine fiberglass mat, making the battery spill-proof. This enables shipment without hazardous material restrictions. The plates can be made flat to resemble a standard flooded lead acid pack in a rectangular case; they can also be wound into a cylindrical cell."​

As mentioned in the above quote, non-AGM batteries are frequently called flooded cell batteries. Many of the newer flooded cell ones are also sealed and maintenance free, and therefore cannot have water added, but not sealed to the same extent as AGM. Also, due to the glass mats holding the electrolytes, AGM batteries can be used at any angle or even upside down.

What you said about the emergency relief valve on AGM batteries is correct.