rando/Vic,
I have been searching, downloading and reading numerous industry as well as numerous scholarly articles on vehicle lead acid batteries trying to find data on failure rates and causes.
With one exception all of the information appears to be analytical model based. Because manufacturers and the battery industry give information on expected battery life that is shorter than the analytic models predict I suspect that there are proprietary data out there that is not readily accessible. I hoped to run across some of that data in the academic papers but I did not.
The one exception I found is a JD Powers report summarized as follows:
- New to the top 10 list of problems reported in 2017 is battery failure. In fact, 44% more owners report a battery failure this year than in 2016. Batteries are the most frequently replaced component not related to normal wear and tear in 3-year-old vehicles at 6.1%—up 1.3 percentage points from 2016.
http://www.jdpower.com/press-releases/2017-vehicle-dependability-study
This is attributed to chronic undercharging due to the newer "smart" vehicle electronics.
Here is a link to an article based on the JD Powers study:
https://www.forbes.com/sites/jimgorzelany/2017/03/01/why-jd-power-reports-44-more-car-owners-are-having-battery-problems/#5eefb723323c
Indeed, shorter life due to chronic under charging is exactly what rando has asserted and is consistent with data from Vic on his vehicle.
The disappointing part is that I searched for "real world" lead acid battery failure information using multiple search terms which variously included "vehicle", "car", "fleet", and "service use". I found lots of links to industry data and academic research on failure modes, failure analysis and failure prediction but no data on real world failure rates in vhehicles or campers/RVs besides the JD Power study.
I did find one "real world" academic study on valve regulated lead acid (VRLA aka sealed or SLA) battery performance in stationary utility applications. I am not sure it is very helpful except to underscore the susceptibility of VLRA batteries to under or over charging.
http://www.sandia.gov/ess/publications/SAND2001-1110j.pdf
The Sandia study does conclude, among other things, that "Inadequate float-voltage setting may be an important life-limiting factor for VRLA cells in float duty". For real world use in vehicles and campers I think that can be reasonably interpreted to be improper or perhaps inadequate float stage charging.
It may be possible to use google trends to analyze search terms and related information but that is a large task. I did try a search on google trends analyses for batteries but I did not get any definitive hits. There are a lot of google trends data pertaining to batteries out there however. I think it is a big research and analysis project to try to use that data.
All we are left with is model based predictions coupled with manufacturer and industry information and claims along with anecdotal data. We each have our own experiences and there are lots of on-line comments by others, but collecting all that information and doing a statistical analysis is beyond my time and interest.
So I will summarize, with all due respect, that some folks get long life from their batteries and some folks do not. The reasons why some do and some don't are not clear and after searching I have found no data to better understand that except anecdotal accounts posted on the web - most of which have poor actual data content and as a result have low signal to noise relative to understanding why their batteries failed.
All the analytical studies show that valve regulated lead acid batteries (SLA, AGM and Gel) are just as susceptible to pre-mature failure from chronic overcharging as they are from chronic under charging. The only vehicle related study I found (JD Powers) suggests that undercharging may be more common than overcharging. However, based on the JD powers and Sandia studies incorrect charging is a reasonable generalized characterization of these failures.
It is interesting that the range of expected life for a starting battery given in the industry and manufacturer sites ranges from a low of 3 - 4 years to a high of 6 - 7 years with the most common lifetime expectation given as 4-5 years. This is several years shorter than the lifetime that the analytical battery models would suggest so it is clear that real world use is not well modeled and is highly variable.
Similarly, the industry numbers for deep cycle VLRA battery life ranges from 7 - 10 years with analytical studies showing years longer.
All of these lifetime estimates are tied to specific use scenarios relative to depth of discharge, frequency of DOD and temperature as well as charging through the various stages. Clearly there are many factors which can diminish usable battery life. However, my assessment from my reading is that the most common primary reason VLRA batteries fail pre-maturely is related to undercharging and perhaps close behind, overcharging.
So I return to the thought that instrumenting batteries to understand the state of charge and charging stage is important if one wants to be able to maximize battery life. Coupled with that is having battery charging equipment installed that provides the proper charging through the charging stages.
In the end the pre-mature failure consequence of not properly charging a VLRA battery will probably not be realized for several years and it may be difficult to ascertain the cause of pre-mature failure post-facto unless one has been monitoring the battery condition regularly along the way. Further, it is not al all clear how much life is lost with a pre-mature failure in a given application. I could be several years and it could be much less than that.
For those of us who have expensive batteries whose life we want to maximize I think it prudent to instrument the battery(s) with a battery monitor and to make sure that the batteries are charged appropriate with the specific battery manufacturer recommendations. This will not guarantee longer battery life because there are other battery life limiting factors such as temperature as well as deep discharging and frequency of deep discharging that varies significantly from installation to installation, but it seems to me it is the best we can do and it is reasonable to do.
All reading this please understand that I am NOT trying to ring any alarm bells and I am not claiming that simple battery charging installations are a problem. Indeed, many people use solenoids to control multi-battery installations and many of them seem to be happy with these devices. However, there is no way to know if they are getting the maximum life out of their batteries or not.
So all I am saying that if one wants to take measures to maximize battery life there are things that can be done (as I have documented in this topic). Whether or not those measures are worth the trouble will only be known when the battery fails (hopefully many years later) and it is possible that spending the time and money installing this equipment will not yield much additional battery life but unfortunately there is no way to know ahead of time. In that regard I guess it is somewhat akin to buying insurance vs being self insured. Whether one goes to the cost and trouble of installing this equipment to maximize battery life is a personal decision.
I hope all of this is clear, understandable, and informative.
My path forward because of the cost of the batteries in my truck and camper is to:
- instrument the the truck and camper batteries so I can monitor the charge stage and the charge state (SOC/DOD)
- use an ACR and the manunal switch to control the bulk charge to my house battery bank from my truck when driving and allow manual connection to charge or jump start the truck battery from the camper battery bank
- rely on my solar system to properly finish charge and maintain my camper battery bank in the appropriate absorption and float stages
- use a wall powered battery maintainer when the solar system is not working (i.e. whenever the camper is stored or placed for a prolonged in a way that blocks the solar panels from the sun)
If there were a device that would allow charging my multi-chemistry battery system with automatic stage charging as well as provide a way to jump start my truck battery from the camper batteries then I would seriously consider buying and installing it, but as far as I have been able to determine such a device does not (yet) exist for consumer use.
Quick Glossary:
Flooded Lead Acid - FLA (aka capped, vented ==> the traditional car battery)
Valve Regulated Lead Acid - VRLA (also known as sealed lead acid)
Sealed Lead Acid - SLA
Absorbent Glass Matt - AGM
Gel
Ref:
http://batteryuniversity.com/learn/article/lead_based_batteries
http://batteryuniversity.com/learn/article/absorbent_glass_mat_agm
http://batteryuniversity.com/learn/article/bu_201b_gel_lead_acid_battery
Regards,
Craig
P.S. Reminder that all of this was stimulated because I had an expensive valve regulated lead acid (sealed) AGM battery in my truck which failed at just over 4 years and which I decided to replace with a much cheaper OEM Flooded lead acid (FLA) battery. That created a complication in that I now have an FLA battery in my truck and my camper house batteries are expensive VLRA AGM as batteries which have different manufacturing charging requirements than my truck FLA battery.