How to recondition a battery - PeachParts Mercedes-Benz Forum

turbobenz · #1 07-10-2008, 06:53 PM

The battery in the sd has really been below par lately. It turns the car over just slow enough to not start. Even hot. And since these things im guessing are like 100 bucks new how can I get a little more life out of it? I know its not the alternator as I put my 300d's battery in it and its been good for about a week. What about slow charging? Say an amp or so? Do battery's actually need to be "refilled" with water or is that just something from the 70's?

And how much more is the white battery than just a standard autozone battery? I want the white one

t walgamuth · #2 07-10-2008, 07:13 PM

Most batteries can have liquid added. Usually though if they are very low they are not long for this world.

Tom W

Hatterasguy · #3 07-10-2008, 07:29 PM

If cash is short get the Autozoo battery, I paid like $70 for mine. Don't know what MB is charging for the white ones. I paid around $105ish for mine 4 years ago. I guess I'll find out this spring when I get a new one.

You should check the water in your battery.

tangofox007 · #4 07-10-2008, 07:37 PM

Quote:

Originally Posted by turbobenz

And since these things im guessing are like 100 bucks new how can I get a little more life out of it?

Trying to squeeze a little additional service out of a weak battery is false economy at its finest. Possible unintended consequences include damaging your alternator and starter, damaging to the vehicle due to excessive outgassing and boilovers, and getting stranded at an inconvenient time or place.

A typical battery has a monthly cost of that is less than the cost of a couple quarts of diesel fuel. Not exactly great savings potential; even less if the battery is covered under a prorated warranty.

barry123400 · #5 07-10-2008, 07:42 PM

In general once a battery has seen better days thats usually about it. You can usually remove the sealing caps and if the battery is pretty dry deal with it and charge and check it.
A poor battery does make your alternator work too hard. There can be false economy here as mentioned. Unfortunatly I have several batteries on their way out. It is not the best solution but occasionally an auto wrecker has some cheap batteries that checked out well. It's up to you to decide on the credability of the seller.

Johnson Chan · #6 07-10-2008, 08:17 PM

The thing I want to know is how old is the battery? A lot of batteries have 2-3 year free replacements.

Before winter starts, take the battery out and take it to autozone or advance, etc. where they have the free battery testing and charging service. Make sure it works or replace it.

Trying to squeeze a little out of a battery is not good. It can leave you stranded and waiting for AAA, etc. Sitting in a car in 20 degree weather waiting for a jump is NOT my idea of fun.

BTW, Mercedes 1-800 number does offer free jumps and I have used this before like 10 years ago. Its free, but you still have to wait and I tip the tow truck driver.

Mercedes makes a BLACK battery that is gel filled and a lot like optimas. It fits perfectly, looks nice, etc. but also has a heavy price tag. I have been using one for 2 years and it does work great.

There are smart battery chargers you can buy that desulfates the battery and trickle charges it, etc. For a good quality one, expect to pay $100 maybe more.

They kind of work, but kind of dont, it depends on how wore out the battery is, don't beleive the marketing and hype that you can "revive all old batteries", etc. for me, it only worked on 1 out of 4 junk batteries I had. Then the smart charger broke and I had to return it, lol.

They do make stuff that you can pour into a old battery and it supposedly desulfates it and revives it, BUT on the Mercedes black batteries, there is a label that clearly tells you not to remove the caps ever and you cannot remove the caps without breaking the label. so much for that idea....

But I agree with tango. Batteries are cheap and easy to replace compared to starters or alternators.

probear · #7 07-10-2008, 08:58 PM

If the battery has or is discharged, the correct method is to charge is on a charger. That takes a lot of stress off of the car system components. Idling will not fully charge a battery.

First, before charging, I would check the voltage between each cell. A wide variance could indicate an internal short or shorted cell. Not good. If it has been boiling off water, then you also need to check the charging system.

What ever you do, make sure to check it prior to trying to charge it. They can and will explode. I have the experience to back that statement.

Fortunately, the battery was out of the boat at the time.

Using a weak battery can cause you a multitude of headaches, including starter issues.

babymog · #8 07-10-2008, 10:43 PM

First, be sure it is full. Use distilled water to bring it up to the bottom of the fill tubes, most batteries do have removeable caps although they're a bit more difficult than the old days.

Leave the caps off for charging.

Then charge at 13.4vdc at a high-amperage if necessary, until it is drawing only an amp or two.

Now you can charge at a 14.3vdc equalization rate for an hour to 12hours. Best to do this in a cool environment, and monitor battery temperature. If it gets too warm it will warp the plates and ruin the battery.

This can recondition a battery that has become weak from partial / incomplete charging, and remove much of the sulfate from the plates. Results will vary, some batteries bounce back better than others.

You should be aware of and take all necessary precautions around the battery, the sulfuric acid will boil during equalization and hydrogen (explosive) is produced during charging and discharging.

turbobenz · #9 07-11-2008, 04:49 AM

I took the caps off the cells and am not sure if they are filled to the correct level. There was liquid visible but when I took a piece of wood and stuck it down there to check the level it was only about an eight inch deep. This may be alright though as this may just be the top of the lead and copper plates. Anyone know anything about the fill level?

Recently in the 300SD the starter failed. I replaced it and now Im having this battery problem which leads me to expect that the previous dying starter was drawing a huge amount of current thus destroying the battery. It has enough CA to start a car so I put it in the young car to see if I can bring it back to life (easier car to start and probably a better charging system)

turbobenz · #10 07-11-2008, 04:52 AM

Quote:

Originally Posted by babymog

First, be sure it is full. Use distilled water to bring it up to the bottom of the fill tubes, most batteries do have removeable caps although they're a bit more difficult than the old days.

Leave the caps off for charging.

Then charge at 13.4vdc at a high-amperage if necessary, until it is drawing only an amp or two.

Now you can charge at a 14.3vdc equalization rate for an hour to 12hours. Best to do this in a cool environment, and monitor battery temperature. If it gets too warm it will warp the plates and ruin the battery.

This can recondition a battery that has become weak from partial / incomplete charging, and remove much of the sulfate from the plates. Results will vary, some batteries bounce back better than others.

You should be aware of and take all necessary precautions around the battery, the sulfuric acid will boil during equalization and hydrogen (explosive) is produced during charging and discharging.

Whats the bottom of the fill tubes? As they just a tube leading to the individual cells? If so then I believe that these are at the correct level. I have an old 3 amp charger and a ammeter so I try that tomorrow.

Cervan · #11 07-11-2008, 05:09 AM

take the caps off and fill it with distilled water, make sure its distilled and has no minerals added. minerals will destroy the battery quicker than with no water. its not as bad as everybody else deems it to be, my battery came with my mercedes had allmost no water, i filled it up with water, best battery ive ever owned now.

vstech · #12 07-11-2008, 09:00 AM

Why do you want the white battery?
my local advance auto sells both the black and the white battery. side by side comparison, the black has 1000CCA the white 950 the black has a 3 year replacement the white has a 3 year replacement, the black has an 875 duty cycle, the white has a 750 duty cycle... aside from difficult to use flip up handles that fold down neatly into the battery and the white color... why get the white one?
it's also $50 more... 74 for the black one, 124 for the white one...
I am seriously asking. I want to know why the white one is more desirable. the store clerk could not tell me why it's more expensive, or why it would be better... I still wanted to get it.... I resisted. but I wanna know why it's better.

JCSC2 · #13 07-11-2008, 01:02 PM

Quote:

Originally Posted by vstech

Why do you want the white battery?
my local advance auto sells both the black and the white battery. side by side comparison, the black has 1000CCA the white 950 the black has a 3 year replacement the white has a 3 year replacement, the black has an 875 duty cycle, the white has a 750 duty cycle... aside from difficult to use flip up handles that fold down neatly into the battery and the white color... why get the white one?
it's also $50 more... 74 for the black one, 124 for the white one...
I am seriously asking. I want to know why the white one is more desirable. the store clerk could not tell me why it's more expensive, or why it would be better... I still wanted to get it.... I resisted. but I wanna know why it's better.

The white battery isn't better. It cost more money to make the white plastic than the black. Mercedes and BMW still require the batteries to be made in white if they are being sold at dealers. Years ago all European size batteries were white. But not so much anymore. I've seen some white ones that are made in Spain. That could also cause the cost to increase for shipping as well.

vstech · #14 07-11-2008, 01:56 PM

YOU'RE KIDDING!!!!
it's the white plastic that is so expensive???

tangofox007 · #15 07-11-2008, 02:01 PM

Quote:

Originally Posted by JCSC2

It cost more money to make the white plastic than the black.

Then no wonder a white battery costs $50 more than a black one!!! Pink plastic must be really expensive, because all of the pink batteries that I have purchased were pretty expensive.