Hi everyone, so i got my hands on a Bosch S4 from one of my dads company vans, it was fitted in April last year then the van blew its engine in july and has not turned a wheel since, the battery was flat when i went to remove it and it reads 11.45 volts on my multimeter, currently have it hooked up to a maintenance charger.

Is it worth swapping it for my 300A 61Ah oem battery which is about 5 years old and showing signs of slow starting on cold mornings.

And what is the best way to determine battery health and how best to recover it.

maintainence charger is best way to recover it. VERY low amp charge for a long time.

If it physicaly fits then there is no issues but if you cant get it to float to 12.6v i'd steer clear of using it

I have exactly same thing but i think mine is a Bosch S4 005 (sticker on front) Athough Eurocar Parts lists the part for my car as 027 when you put the reg in i would check yours using the reg checker. I think from memory diesels need a bit more oomph from the battery to start than a petrol.

http://www.eurocarparts.com/ecp/c/Skoda_Octavia_2.0_2006/p/car-parts/car-electrics-and-car-lighting/electrical/car-battery/?444770277&1&aa67f1c7188b4a36f7d349dc908afd3df48ac965&000020

My car is still on the original battery (7 Years +) so im going to wait till it stops working until i fit this S4.

Read here:

http://www.briskoda.net/forums/topic/262596-what-ah-battery-does-your-fl-octavia-vrs-have/

and here:

http://www.briskoda.net/forums/topic/258992-is-the-octy-vrs-cr-170-diesel-battery-not-up-to-the-job/

Yep i saw those posts.

I do between 200-300 miles a week, dont have heated seats or anything with huge battery drain.

Ok guys, i just checked the battery, its up to 11.8 volts and its been hours since i put it on charge, pretty much the same time i started the thread.

Is this battery past it

how do you mean up to 11.8v?

do you mean you've taken it off charge and let it drop to its float voltage?

No, its still charging, i was checking it. I was expecting 12.6V upwards

how does your charger work?

It should be charging 13v+. My ctek charges at 14.4v normaly, 13v in power supply mode and 14.4v but really low amps in recond mode

Im not sure exactly how it works, its my dads.

it should slowly increase the voltage to 14.3v and it will automaticaly change to charge verification stage

http://www.tecmate.com/pdf/TM151%20OptiMate%203+%20User%20Manual.pdf

Regular lead acid batteries really, really dislike being left on their own. If removed from a vehicle or on a layed up vehicle they should be supported by a maintenance regime. Or disposed of responsibly.

Batteries will loose charge over time, a sort of entropy artifact. As the cells discharge, the H2SO4 becomes more dilute, the acid breaking down into H2O and elemental sulphur. If left, sulphation of the plate occurs, where the sulphur from the acid precipitates and hardens over the plate surface, reducing the effective plate area and hence ability of the battery to deliver current on demand ie knackered. Mild cases can sometimes be recovered, bad examples, it is the end.

The active ingredient is lead peroxide which is pressed into the plate grids and if left gradually loosens, falls out and shorts out the cell, killing the whole battery.

Charging at too high a rate will also cause the plates to disintegrate, which is why Ryan recommended the maintenance charger.

There are alternative lead acid technologies which will survive this sort of treatment, such as AGM - Absorbed Glass Mat.

Obviously more expensive, but cheaper than two ordinary batteries, cue the bunny.

Yeah I know its not in the best condition, if only I had known it had a new battery fitted a few weeks before the van went bang I would have jumped on it then.

I have still got it on charge and we are up to 12.15V thats after 24 hours on charge. Anything else I can do, fit it in my car and go for a long run maybe? I have a big battery charger but its for fast charging, I can only imagine this would ruin the battery more.

just leave it charging mate.

Your car will not be able to charge it anyware near aswell as the charger.

Its set to slowly up the voltage as it charges. Its a wierd way of doing it but its how it works. My Ctek XS7000 took 5 days on a mates battery once to fully recondition it as it was very poorly

Dont use a fast charger, it will damage it more as you say.

O well here comes the long wait, I might sneak it into the office to save on the electric bill :think: