Concrete and battery

[johan]

A bike workshop manager told me recently, that I shouldn't' store the bike's battery on concrete floor, as it will drain/damage it.

I said, I doubt concrete does drain the battery, but he insisted.

It doesn't make any sense.

Is this a myth needed to be busted!?

[oneofsix]

A bike workshop manager told me recently, that I shouldn't' store the bike's battery on concrete floor, as it will drain/damage it.

I said, I doubt concrete does drain the battery, but he insisted.

It doesn't make any sense.

Is this a myth needed to be busted!?

totally doesn't make sense. The electrodes are not in contact, concrete is less conductive than the metal trays batteries often sit in, the case insulates it from the floor and ensures the electrolyte within the battery can not interact with the concrete. Wonder if his experience has related to damp sheds with concrete floors where the concrete floor is just co-incidental to the damp conditions that are allowing the charge to leak from the battery?

[george formby]

totally doesn't make sense. The electrodes are not in contact, concrete is less conductive than the metal trays batteries often sit in, the case insulates it from the floor and ensures the electrolyte within the battery can not interact with the concrete. Wonder if his experience has related to damp sheds with concrete floors where the concrete floor is just co-incidental to the damp conditions that are allowing the charge to leak from the battery?

Cold & damp.:yes:

[johan]

Cold & damp.:yes:

How is cold and damp on concrete floor different from cold and damp sitting in the bike?

[oneofsix]

How is cold and damp on concrete floor different from cold and damp sitting in the bike?

if it just the cold and damp then none but in the bike the battery is connected to the electrical system so the electrodes aren't open to leaking to the damp atmosphere. Also your expectations of a battery in a bike are different to one sitting on the floor. It is more likely you would expect the one on the floor to be as charged as when you first put it there. This could all lead to the creation of the myth that it is the concrete floor that is bad.

[Maha]

How is cold and damp on concrete floor different from cold and damp sitting in the bike?

Put a rubber mat on a concrete floor for a couple of hours then lift up, you will see the amount of moisture that gets drawn up. Even a plastic bucket will have the same effect.

[nodrog]

take your pants off and sit on a concrete floor overnight, id be suprised if your ring piece isnt frozen to the floor in the morning.

[White trash]

Concrete fucks batteries and also tyres stored for any time on it. Don't know the science behind it, just know it happens having had experience myself.

[imdying]

Yeah, what he said :laugh:

It's like a big fat heat sink... it's cold, so it sucks the heat out of everything around it, including your battery. In the bike it's surrounded by air, which doesn't conduct heat.

Ignore what you've been told and leave it on the concrete if ya like :sunny:

[Max Preload]

Yeah, what he said :laugh:

It's like a big fat heat sink... it's cold, so it sucks the heat out of everything around it, including your battery. In the bike it's surrounded by air, which doesn't conduct heat.

Ignore what you've been told and leave it on the concrete if ya like :sunny:What he said.

The first cold snap of autumn also sees an abundance of overnight battery failures for a reason.

[johan]

great input thanks

[notme]

Ah, this old chestnut.

There's a buttload more info available if you want all the details, but the short version is that it's total bollocks - NOWADAYS. It used to have a basis in fact, about 50 to 60 years ago when automotive batteries were built differently, which is why the myth is sill believed and spread mainly by old timers.

With a normal modern auto battery, putting it on a cold concrete floor will actually cause it to self discharge less than if it was on a wooden benchtop due to the concrete heatsink effect :-)

[Paul in NZ]

Ah, this old chestnut.

There's a buttload more info available if you want all the details, but the short version is that it's total bollocks - NOWADAYS. It used to have a basis in fact, about 50 to 60 years ago when automotive batteries were built differently, which is why the myth is sill believed and spread mainly by old timers.

With a normal modern auto battery, putting it on a cold concrete floor will actually cause it to self discharge less than if it was on a wooden benchtop due to the concrete heatsink effect :-)

Erm - define a 'normal' battery?

[notme]

Erm - define a 'normal' battery?

Yeah maybe bad wording on my part - what I mean is a standard off the shelf battery - just trying to cover myself for the one guy on KB who has replicated a 1930's technology battery and says that it does discharge on a concrete floor (which it will!), or the guy who is running a 380VDC electric bike and says that his battery discharges on the concrete floor (which it miiiight just barely).

So a standard, off the shelf, 12V automotive battery, of any chemistry.

EDIT: more ass-covering - it also only applies to a battery with less than say 500AH capacity (if lead acid chemistry). i.e. a typical bike/car starting battery.

[notme]

It's like a big fat heat sink... it's cold, so it sucks the heat out of everything around it, including your battery.


Which is a good thing - it slows the discharge rate. It'll discharge slower than sitting in the bike!



The first cold snap of autumn also sees an abundance of overnight battery failures for a reason.

It does - and that reason is that the typical automotive SLI battery performs worse as the temperature drops. This is realted to the self discharge rate - the same mechanism that slow the self discharge when cold is what's responsible for the battery being able to deliver less start current on a cold morning.

[imdying]

Empirical evidence would suggest otherwise, but you can look after your battery any way you see fit. I fixed the problem by fitting batteries that don't discharge themselves.

[notme]

Empirical evidence would suggest otherwise

The suggestion is correct, the misinterpretation that concrete has anything to do with it is where the flaw lies.


but you can look after your battery any way you see fit.
Thanks for that - I will continue my current practices of looking after batteries based on science, not witchcraft, voodo, superstition, or old wive's tales :facepalm:



I fixed the problem by fitting batteries that don't discharge themselves.
I'm guessing LiFePO4 .... which do self discharge, its just very low (like 1.5%/month). Lead Acid's are shitters for self discharge - it can be up to 40% loss from full charge in 3 weeks!

[Flip]

Sounds like a load of rubbish to me.

Given the surface ground temperature is an average of the day and night temps I fail so see any correlation between being on a concrete floor or not. Sounds like folk don't understand the difference between temperature and thermal conductivity.

[TimeOut]

It does - and that reason is that the typical automotive SLI battery performs worse as the temperature drops. This is realted to the self discharge rate - the same mechanism that slow the self discharge when cold is what's responsible for the battery being able to deliver less start current on a cold morning.


Coupled with colder / thicker oil (harder to turn over) is why a lot of batteries fail at the start of winter

[notme]

Coupled with colder / thicker oil (harder to turn over) is why a lot of batteries fail at the start of winter

Good point - and there's also the petrol issues with temperature (evaporates more slowly which is why start ya bastard and other ether products work for cold weather starts) and what's starting to happen nowadays as ethanol is added to fuel, is that there are problems in very cold places where fuel lines are freezing and breaking because the ethanol traps water out of the fuel.

But yeah - with reference to the batteries, it's simply that lead acid SLI batteries will deliver less start current when thier little toes are cold.

[Max Preload]

It does - and that reason is that the typical automotive SLI battery performs worse as the temperature drops. This is realted to the self discharge rate - the same mechanism that slow the self discharge when cold is what's responsible for the battery being able to deliver less start current on a cold morning.It's not that there's an absence of capacity due to self-discharge that causes a cold battery to not be able to supply its stated delivery current - it's the fact that in the cold the chemical reaction that occurs does so at a much lower rate which compounds the already reduced (due to age) capacity the battery has.

[notme]

It's not that there's an absence of capacity due to self-discharge that causes a cold battery to not be able to supply its stated delivery current - it's the fact that in the cold the chemical reaction that occurs does so at a much lower rate which compounds the already reduced (due to age) capacity the battery has.

Correct - "the same mechanism that slows the self discharge when cold is what's responsible for the battery being able to deliver less start current on a cold morning. "

[F5 Dave]

So why was the battery taken out of the bike to get stored on the floor, concrete or otherwise?

Answer= because it was fuked.

Given an optimistic charge over night & gee it looks fine now, reads alright open cct.:facepalm:. Oh dear it's kuzed.


Bloody concrete. Maybe I should shag-pile.

But that might hurt & if anyone caught me. . .

[schrodingers cat]

They go flat because the mice hook their disco lights up to it having mad bastard raves night after night.

This is a fact. I researched it on the internet.

http://media.tumblr.com/tumblr_levuajxq7W1qb5qpk.jpg

[Bonez]

So why was the battery taken out of the bike to get stored on the floor, concrete or otherwise?

Answer= because it was fuked.
Untrue. It could be removed because the bike is stuffed.