Something is short on my van, but what?

[eccerr0r]

Re: Something is short on my van, but what?

So nobody knows how much longer? And what's the concentration needed to make a difference, assuming normal charged battery acid is around 30%?

Is it worth it if you live in a hot environment, simply draw out some acid from your battery and refill with some deionized water, instant reduction in acid concentration - reduction of battery capacity and increase of ESR. However if you're in a warm environment, reaction speeds and lower motor oil viscosity due to temperature should allow you to start even with a compromised battery.

Also not considered is if you do discharge the battery all the way, if the sulfuric acid is the limiting reagent, you'll end up with a really watery battery that cannot be recharged - forced to add more acid back to get it to conduct once more. Another drawback is with a more dilute mixture, the boiling point is lower, and water will be lost to evaporation faster, and if not refilled in time, also contributes to sulfation.

[dicky96]

Re: Something is short on my van, but what?

i have not seen a van with an underfloor engine in europe for years - only mercedes did that here anyway.
probably for safety, engines are always ahead of the firewall.

But as I mentioned earlier my Nissan Vanette Cargo 2.3D has a mid-mounted engine under the front seats. There are loads of those vans on the roads here, there is not a day I go driving without seeing at least one other, and usually several more than that. The bonnet (hood to some of you) just has the radiator, spare wheel and battery/fusebox.

Last time I checked we are in Europe (and in the EU single market/shengen zone but not the customs union)

[Curious.George]

Re: Something is short on my van, but what?

hot temps, batteries sulfate real fast.

Yup. Especially important to make sure electrolyte level is "up" to keep the plates COMPLETELY covered.

I used to get 6-8 years out of a (good) battery living in colder climates. So, when I'd have starting problems in ~3 years, it was a crap shoot as to whether the problem was the battery or alternator (I had one vehicle that would routinely blow the diodes in the alternator so learned early on to check THAT before screwing with anything else).

Here, it's easier just to pull the battery a month before the prorated portion of the warranty kicks in and bring it in for a replacement. Folks look at the date and don't even bother to bench/load test it.

I've not had to BUY a battery in close to 30 years using this approach.

[Of course, folks who need to hire someone to replace the battery end up having to incur THAT cost.]

[Curious.George]

Re: Something is short on my van, but what?

Moving the battery means lengthening the wire to the biggest load in the vehicle -- the starter. That means increasing the wire gauge

so??

It increases cost. You do realize the difference in wire lengths required to get a battery into the "trunk"/boot vs. keeping it under the hood, a couple of wire-feet from the starter AND alternator?

Have you any FIRST HAND experience designing high volume items for the consumer market? If so, then you'd realize that FRACTIONAL PENNIES are considered when evaluating solutions.

Why are batteries so many different SIZES -- instead of standardized and sized for the largest vehicle? (surely the smallest vehicle could be made to accommodate such an oversized battery! and, it would benefit from having more reserve capacity)

Why aren't all vehicles equipped with sun/moon roofs? Power seats -- driver side AND passenger side? "Navigation"? Cruise control? Surely the manufacturer would save by not having to make so many different versions of EACH vehicle! And, car salesmen would have less "selling" to do!

why do you always post dismissive responses to people?

It's a simple FACT. Does it hurt your feelings if I say "The Sky is Blue"? Or, "2+2=4"?

Stop being a f*cking pussy, for christ's sake!

[stj]

Re: Something is short on my van, but what?

How big are the engines? How many CCA required? Note that a van's engine is, already, ALMOST *in* the passenger compartment.

i have not seen a van with an underfloor engine in europe for years - only mercedes did that here anyway.
probably for safety, engines are always ahead of the firewall.

Moving the battery means lengthening the wire to the biggest load in the vehicle -- the starter. That means increasing the wire gauge

so??

why do you always post dismissive responses to people?

[Curious.George]

Re: Something is short on my van, but what?

how much longer is 'much longer'?

Diluting the electrolyte, if you can have a reservoir to keep enough sulfate ions around will end up increasing ESR of the battery. If the same volume of liquid is kept as before, capacity will be lost. In a lead acid cell, electrolyte is a reactant.

Acid corrodes. The more aggressive the acid, the more aggressive the corrosion.

Batteries are chemistry, not "electronics". So, considerably more sensitive to their operating conditions (you can't just "put a bigger heatsink/fan" to solve SOA issues). If you have to tolerate very low temperatures (chicago winters), the battery appears to shrink by a factor of four (the chemistry slows and the mechanical load gets larger). So, there's little value in trying to increase the battery's life by DECREASING its capacity! (unless you like jump-starting your car in cold weather)

CAR batteries are relatively inexpensive and inexpensive to install/replace. They also see a fair bit of EXPECTED wear. Contrast with "emergency lighting" that often sits UNCHALLENGED for years at a time! And, with much higher replacement/servicing/failure costs (it's not like you can hope that the NEXT power outage you'll be back on top of your game -- unlike starting the car, tomorrow!!)

Applications that really try to get the best performance/longevity out of a battery include things like (legacy) submarines, CO "battery", etc. There's very little incentive for a car manufacturer to have their batteries last any longer!

The same argument applies to batteries in UPSs; the manufacturer wants you to be able to QUICKLY recover from an outage -- even if that comes at the expense of having to replace batteries more often (you've likely got STAFF that can do that for you!)

[Curious.George]

Re: Something is short on my van, but what?

so the solution is to return to what Jaguar and Rover used to do and fit a sealed battery box in the trunk.
most custom/performance shops sell battery boxes for this purpose.

btw, in europe most vans and the PT-cruiser all mount the battery under the seat inside the cabin.

How big are the engines? How many CCA required? Note that a van's engine is, already, ALMOST *in* the passenger compartment.

Moving the battery means lengthening the wire to the biggest load in the vehicle -- the starter. That means increasing the wire gauge (or, expecting the starter to operate at a lower voltage/higher current).

It also places the "mess" that is traditionally associated with battery maintenance in a place that has historically been "kept reasonably clean".

[stj]

Re: Something is short on my van, but what?

so the solution is to return to what Jaguar and Rover used to do and fit a sealed battery box in the trunk.
most custom/performance shops sell battery boxes for this purpose.

btw, in europe most vans and the PT-cruiser all mount the battery under the seat inside the cabin.

[eccerr0r]

Re: Something is short on my van, but what?

how much longer is 'much longer'?

Diluting the electrolyte, if you can have a reservoir to keep enough sulfate ions around will end up increasing ESR of the battery. If the same volume of liquid is kept as before, capacity will be lost. In a lead acid cell, electrolyte is a reactant.

[Curious.George]

Re: Something is short on my van, but what?

i once heard in countries like africa they use a weaker acid solution because of the constant warm temperature and no chance of freezing and this making the batteries last much longer

Yes. Lowering the concentration increases battery life -- at the expense of capacity.

The old-fashioned "emergency lights" (with the big, transparent, lead acid batteries) were used like this.

(Note that emergency lighting is typically installed indoors -- no temperature extremes!)

[petehall347]

Re: Something is short on my van, but what?

i once heard in countries like africa they use a weaker acid solution because of the constant warm temperature and no chance of freezing and this making the batteries last much longer

[CapLeaker]

Re: Something is short on my van, but what?

hot temps, batteries sulfate real fast.

[eccerr0r]

Re: Something is short on my van, but what?

I should have tested my batteries individual cells as a I replaced them. Not sure if my climate has "extreme" temperature changes but it goes from -20C to +38C around here over the year with some outliers. The highs are not as high as some places in the world, but it does get somewhat chilly. However I do tend to get my 7 years on my car starting batteries, and it's been fairly consistent.

Also note that underhood temperatures get quite hot, though unsure if it's a straight temperature over ambient or not. Though cold is still cold for reaction speed (cold cranking amps), high temperature is bad - for electrolyte loss. Then also the other problem is vibration causing sloshing and spilling of electrolyte as well as microcracks in the plastic near the terminals causing small bits of electrolyte to leak out and cause corrosion... Make sure your battery tiedowns are tight to extend the life of your batteries!

[Curious.George]

Re: Something is short on my van, but what?

I don't think temperature stress will have much of an effect on the battery - it's under the bonnet but the van has a central mounted engine (under the front seats). Out temperature is always between 35C (95F) summer day and 16C (61F) winter night, all year unless we get a summer Calima when it can hit 45C/113F, or an exceptionally cold winter night when it can get as low as 12C/54F.

Here (AZ, USA) the heat EATS batteries. After about *3* years, encountering ANY starting problems means: "replace battery". Suppliers don't even bother to TEST the battery as they know this to be the case.

As most batteries have prorated warranties (age determines how much of the batteries cost you are credited with), the 36 month number is significant: one usually gets 100% of the battery's price refunded in this period.

OK still I wonder - the battery charged to 13.1V but the hygrometer was black. Then after a couple days of leaving the battery standing with nothing attached to it, the hygrometer went very faintly green and the voltage dropped to 13.0V

The voltage you are reading is the SUM of the 6 cells voltages. So, the cell in which the "magic eye" is placed might have a poor state of charge (low cell voltage) while the others may have a GOOD (even HIGH!) state of charge. The net result is what you see as the "battery voltage".

It's chemistry. You're making a "solution". There's nothing to "stir" the contents of the battery (electrolyte) so you have to wait for the concentration (of "acid") to come to an equilibrium throughout the battery before the "magic eye" will "see" the increased specific gravity. As the cells are physically isolated (electrolyte from one cell can't mix with that of another cell), you are waiting for electrons to migrate between cells to "distribute" the charge (which manifests as specific gravity).

Then after another day it went green and the voltage was 12.93V

Remember, voltage is only an approximate indication of "state of charge". The specific gravity is more indicative of the battery's health.

I only purchase "fillable" batteries and assume the responsibility for keeping them topped off (lots of evaporative losses, here). In return, I can look at the specific gravity of each individual cell (with a real hygrometer). I record these in my cars' log books so I can see if I'm having a problem with a particular cell BEFORE it affects the battery as a whole.

[dicky96]

Re: Something is short on my van, but what?

Sorry guys it is my wrong terminology that caused the confusion. The battery will be maintenance free then - I just called it sealed as it does not have the little screw in covers where you can add distilled water

The green thing jut looked like a faint LED at the bottom of a narrow hole to me. It does indicate green/white/black. Clearly I have now been educated otherwise

I don't think temperature stress will have much of an effect on the battery - it's under the bonnet but the van has a central mounted engine (under the front seats). Out temperature is always between 35C (95F) summer day and 16C (61F) winter night, all year unless we get a summer Calima when it can hit 45C/113F, or an exceptionally cold winter night when it can get as low as 12C/54F.

OK still I wonder - the battery charged to 13.1V but the hygrometer was black. Then after a couple days of leaving the battery standing with nothing attached to it, the hygrometer went very faintly green and the voltage dropped to 13.0V

Then after another day it went green and the voltage was 12.93V

So quite obviously, something was going on inside the battery while it was standing for three days connected to neither load nor charger - and that is what's puzzling me.

The van started again this morning first touch so it looks like the battery survived the abuse.

[stj]

Re: Something is short on my van, but what?

outside cells are more exposed to temperature swing

[eccerr0r]

Re: Something is short on my van, but what?

I would think that it's fairly equal chance for any particular cell to fail, depends on the welds and plate stabilization. However subject to random vibration I would have to agree the end cells would probably take the most stress, though marginally. The positive electrode also tends to be chemically weaker one I'd suspect, but the mechanical stress is the larger issue.

But yeah the built in hygrometer ends up on cell 2... ideally it should be on cell one near the positive terminal. And thus having the positive terminal closer to the center of the car would extend battery life ever so slightly...

[CapLeaker]

Re: Something is short on my van, but what?

My flooded lead batteries fail to 95% on the outside positive cell. Doesn't matter brand or size or where it sits in. Desulfating batteries that have a bulge seem to die either during desulfation or very shortly after.
The other 5% both outside cells had a bulge and failed to desulfate. So I quit looking at bulged batteries.

[petehall347]

Re: Something is short on my van, but what?

built in hygrometers always seem to be on the wrong cell as its always an end cell dies first .like it can be green and the battery has a shorted cell ..i can never remember which end cell dies first . only real test is fully charge it then let it sit a day or 2 then do a voltage drop test whilst observing the cells for boiling .
saying the battery supplier i use has a tester that does not put a great load on the battery and will tell you its exact status .

[eccerr0r]

Re: Something is short on my van, but what?

Are you sure it's sealed? or just maintenance free?

Flooded batteries typical of cars can be maintenance free, but cannot be sealed as they can generate gases while being used. Flooded cells can have "green/black/white" hygrometers which detect the density of the liquid electrolyte - if it's charged, the liquid would be mostly acid which is denser than water, which is what the electrolyte would be when the battery is discharged.

Green means high density electrolyte = acid = charged.
Black means low density electolyte = water = discharged.
White means no electrolyte = air = you had a leak or you spilled the electrolyte from the not-sealed battery.

If it's really a sealed leakproof AGM battery, possibly cylindrical cell, I suppose it could be a fancy unit with its own selftester but I've yet to ever see one. Since there's no free electrolyte in an AGM or gel cell, these density/specific gravity measurements won't work and you have to depend on voltage to determine state of charge.

Incidentally the hygrometers able to detect electrolyte loss is very helpful and you can only guess whether you lost too much electrolyte in an AGM cell, usually due to evaporation or overcharging.