Consequences of Dead, DEAD batteries?

[rvrepairnut]

Originally Posted by wa8yxm

Insist on new batteries.. though the house batteries, if they are Six Volt pairs.. MIGHT recover and be good for years to come, the chassis battery is toast..

This is the biggest difference between starting and deep cycle


And even knowing that,,, I'd insist on new batteries.

there is no way for any poster here to know what batterys are good and what are bad in this OP unit he,s looking at .No where does he say what year the batterys are etc.Just because batterys are allowed to run dead does not automatically make them no good so to say the house batterys may be Ok and the chassis battery is toast is pure conjecture on your part.What if the batterys are only 6 months old? then what>? still toast?
My chassis batterys(original 31 series)) in my 08 AB got run stone dead last year.I charged them up over 2 day using slow charge and there like new as I type

[RV Wizard]

I would suggest that those wanting to educate themselves on batteries check out this:
http://www.irv2.com/forums/f54/batte...an-141070.html
There are also many other websites that can help. It is possible to ruin new batteries in one day, especially a starting type battery, as the plates are thinner and more fragile.

"Batteries don't die; they're murdered" Concorde Battery Corp.

[MattC]

Originally Posted by rvrepairnut

depends on how old they are,how many times they have been run this low etc.If there 2008 more than likely there not in perfect condition although to try and answer your question it should not have hurt the batterys just because u ran them that dead.in other words they should charge up 100%

I have been a professional doing upgrades to yachts for more than a few decades. I can promise you that the batteries are hurt by this deep discharge. If I could get there with my instruments (my own design), I could prove that the battery capacity was well below specification. I (for a fee) track clients batteries and every single time that the are discharged below 11.5 Volts, there is a loss of capacity. That loss is a very predictable function of the battery age and the discharge level.

This is personal opinion based on years of experience. If the batteries are four years old and were discharged below the power needed to crank the main engine for the chassis battery, it is toast. By the same token if the house battery will not crank the APU with the lights on, it is Real Toast.

Good Luck

Matt

[rvrepairnut]

Originally Posted by MattC

I have been a professional doing upgrades to yachts for more than a few decades. I can promise you that the batteries are hurt by this deep discharge. If I could get there with my instruments (my own design), I could prove that the battery capacity was well below specification. I (for a fee) track clients batteries and every single time that the are discharged below 11.5 Volts, there is a loss of capacity. That loss is a very predictable function of the battery age and the discharge level.

This is personal opinion based on years of experience. If the batteries are four years old and were discharged below the power needed to crank the main engine for the chassis battery, it is toast. By the same token if the house battery will not crank the APU with the lights on, it is Real Toast.

Good Luck

Matt

my 4 year old 31 series batterys(EG) were stone dead.I slow charged them for 48 hours.thats a year ago and still going strong
SG test and load test etc and checked good as new.I sold and installed thousands of car and truck batterys.in very cold winter climates.The damage incured of running a perfect battery dead is minisule.Its not a thing u want to do no doubt but it certainly does not ruin a good battery just because u run it dead now in the OP case like I said who knows what year the batterys are.maybe there no good and maybe there fine its up to him and his dealer to decide .obviously if the dealer is willing to replace them include then go for it
but like I said 4 times now if there still in good shape as maybe there not original running them dead on the lot does not instantly ruin the batterys like your saying.To run out and buy 6 new batterys every time they get run low(dead)
is simply crazy and a waste of money

[MarkofSJC]

Originally Posted by rvrepairnut

there is no way for any poster here to know what batterys are good and what are bad in this OP unit he,s looking at .No where does he say what year the batterys are etc.Just because batterys are allowed to run dead does not automatically make them no good so to say the house batterys may be Ok and the chassis battery is toast is pure conjecture on your part.What if the batterys are only 6 months old? then what>? still toast?

I did fail to mention that those were the original batteries. Unlike tires, I'm not sure if there's a way to determine their "birth" date, but it the coach is a 2008, so it was built in 2007. I did notice that the tires are 2006!

Mark

[cmpncrsaider]

Originally Posted by MarkofSJC

I did fail to mention that those were the original batteries. Unlike tires, I'm not sure if there's a way to determine their "birth" date, but it the coach is a 2008, so it was built in 2007. I did notice that the tires are 2006!

Mark

I think there's a heat stamp on the battery

[jth camper]

Originally Posted by MattC

I have been a professional doing upgrades to yachts for more than a few decades. I can promise you that the batteries are hurt by this deep discharge. If I could get there with my instruments (my own design), I could prove that the battery capacity was well below specification. I (for a fee) track clients batteries and every single time that the are discharged below 11.5 Volts, there is a loss of capacity. That loss is a very predictable function of the battery age and the discharge level.

This is personal opinion based on years of experience. If the batteries are four years old and were discharged below the power needed to crank the main engine for the chassis battery, it is toast. By the same token if the house battery will not crank the APU with the lights on, it is Real Toast.

Good Luck

Matt

What he said. You may get lucky and be able to restore a stone dead battery, but I would not hang my hat on it.
Battery technology has not changed much, even AGM have the same principal as liquid filled battery's the AGM just uses more lead and less liquid.
Stuck in the middle of nowhere with a dead battery stinks. Imo

[MattC]

It may be worthwhile to try, but I did DC electrics for a living for a number of years and even if the battery recovers from a deep (>10V) discharge, there will be a capacity loss. This may not matter much to an RV, but when there is no shore power in the future and diesel fuel is precious (it cannot be replaced mid ocean), then a lot of things matter that don't matter to land dwellers.

We this work for cruising yachts, the kind that rarely - if ever - have shore power. I modified another's design for an instrument that can determine the condition of any secondary (rechargeable) battery. We had regular clients that wanted to know when to replace batteries. When one is talking about replacing an 8D Rolls or Trojan, you are talking about changing out an expensive 170# battery. This is not something you do not want to do if you don't need to.

Several of the owners kept very good logs. Of those that reported that letting the house bank deplete to less than 11.5, all showed significant loss of capacity when next analyzed. I have found that "car like" batteries are much worse in this area than the high end types.

We are still evaluating three different "desulfators" and the results so far are mixed. Much too mixed to offer any statement.

Matt

[rvrepairnut]

Originally Posted by MattC

It may be worthwhile to try, but I did DC electrics for a living for a number of years and even if the battery recovers from a deep (>10V) discharge, there will be a capacity loss. This may not matter much to an RV, but when there is no shore power in the future and diesel fuel is precious (it cannot be replaced mid ocean), then a lot of things matter that don't matter to land dwellers.

We this work for cruising yachts, the kind that rarely - if ever - have shore power. I modified another's design for an instrument that can determine the condition of any secondary (rechargeable) battery. We had regular clients that wanted to know when to replace batteries. When one is talking about replacing an 8D Rolls or Trojan, you are talking about changing out an expensive 170# battery. This is not something you do not want to do if you don't need to.

Several of the owners kept very good logs. Of those that reported that letting the house bank deplete to less than 11.5, all showed significant loss of capacity when next analyzed. I have found that "car like" batteries are much worse in this area than the high end types.

We are still evaluating three different "desulfators" and the results so far are mixed. Much too mixed to offer any statement.

Matt

maybe but 2 different worlds and 2 entirely different situations.I firmly do not beleive that letting house batterys go under 11.5 volts will loose significant capacity.I have run my low several times over the last 2 years and all 4 still work as well as the day they were insta;lled.

[BFlinn181]

The OP is interested in buying a RV that has dead batteries as it sits on the lot. He doesn't know the past history, how old or how many times the batteries have been allowed to go below 11.5 volts. I believe his best bet is to negotiate a price reduction enough to cover new batteries. If the dealer insists in replacing batteries, he needs to make sure they are sized and rated for the coach.

[fredaevans]

Originally Posted by BFlinn181

I'd require price reduction to cover cost of new batteries. If you let them put in new batteries, they could go for the cheapest, weakest batteries and you'd hardly be better off than you started. If they insist on replacement, write down size and rating of the 'dead' batteries in coach and require comparable replacements.

+1 and ooooooh soooo yes.

[MattC]

Originally Posted by rvrepairnut

maybe but 2 different worlds and 2 entirely different situations.I firmly do not beleive that letting house batterys go under 11.5 volts will loose significant capacity.I have run my low several times over the last 2 years and all 4 still work as well as the day they were insta;lled.

You may believe that RVs (Recreational Vehicles) and RVs (Recreational Vessels) are different situations, but I can assure you that (except for the "marine" parts costing more) there are no differences that matter at all. Lead acid battery chemistry is the same regardless of where it is used.
You are very welcome to your opinions.
I will believe my instruments and the confirmed data.

Matt <www.southpointechandler.com>

[rvrepairnut]

Originally Posted by MattC

You may believe that RVs (Recreational Vehicles) and RVs (Recreational Vessels) are different situations, but I can assure you that (except for the "marine" parts costing more) there are no differences that matter at all. Lead acid battery chemistry is the same regardless of where it is used.
You are very welcome to your opinions.
I will believe my instruments and the confirmed data.

Matt <www.southpointechandler.com>

what I meant by different worlds is if your way out on the ocean and your batterys fail u may be in a world of hurt.99% of Rver,s if battery fails your either in a camp ground,at home or very near easy help
so not near near as critical

[BFlinn181]

Vast experience vs vast experience with data. Who you goin' to believe? The OP asked about dead batteries in an RV he has no history of. Should he buy with discount, have batteries replaced as part of the deal or not? The rest of this is just chest bumping.