Topping up a battery

[steve singh]

Hello Chaps,

I've got a battery which has a "charge" indicator window - currently that window is completely clear which I believe indicates that the electrolyte (sp) levels are low (a good battery would have a "green" window).

The car still starts fine but I'm guessing the battery is on it's way out - it's just a matter of time?

Also if a battery is described as "low maintenance" is it possible to still top it up - the manual suggests a replacement battery is needed if the electrolyte levels drop off?

ETA: It's a battery in a mk5 GTI

Cheers

Edited by steve singh on Thursday 23 December 09:39

[steveo3002]

chances are its a sealed battery

doesnt the magic eye indicate low state of charge rather than low electrolite level?

id maybe whack it on trickle charge over night and see what the light says , all the gizmos full on with the cold weather wont be helping it

[PoleDriver]

The 'window' indicates charge state, not electrolyte level.

Even 'sealed' batteries can be topped up, they will have a removable cover somewhere on top which will give access to the fillers. Bear in mind that once you remove said cover there will no longer be a warranty and the battery will not be fully sealed.

[steve singh]

Thanks guys - IIRC the manual suggested the window was used to assess charge & electrolyte levels but I may have got that wrong - I'll double check tonight and report back.

I tried to charge it yesterday but it didn't take a charge - I'm not sure however if my battery charger is fully working as it's quite old - might try the charger on a different battery tonight to rule that out.

In terms of top up points, I can see some covers on the battery under lots of stickers - I guess that's the top up point if I wanted to break the seal - is there a downside to doing this as it's not in warranty?

Also I guess I have to use distilled (not mineral) water?

Appreciate all your help.

[PoleDriver]

steve singh said:

In terms of top up points, I can see some covers on the battery under lots of stickers - I guess that's the top up point if I wanted to break the seal - is there a downside to doing this as it's not in warranty?

Also I guess I have to use distilled (not mineral) water?

Appreciate all your help.

Correct on all points!

If the battery has been allowed to sit for a long period without charge it may have died! Leave the charger on at high current setting for an extended period of time!

[r11co]

steve singh said:

I've got a battery which has a "charge" indicator window - currently that window is completely clear which I believe indicates that the electrolyte (sp) levels are low (a good battery would have a "green" window).

Clear/black - low electrolyte. White - low charge. Green - OK.

Just ditched a battery that was showing black. Ever after a top-up and good overnight charge it was still pretty poor at cranking for more than 2 or 3 seconds - I have no idea how long it was running with the electrolyte low.

£45 for a new batt and no starting problems since (even in -18c).

[steve singh]

Thanks for all your help PoleDriver and R11co - it's appreciated.

If I do need a new battery, is there any places that are particularly cheap?

Cheers

[r11co]

steve singh said:

Thanks for all your help PoleDriver and R11co - it's appreciated.

If I do need a new battery, is there any places that are particularly cheap?

Cheers

If you have a costco membership (or know someone else who has) then get over there and bag yourself a Bosch S5. Not the cheapest but great value as their prices for the Silver range match just about everyone else's price for the Bosch Blue (S4) range. S5 means 5 year guarantee BTW.

Failing that then try performancebatteries.co.uk. Their 'Alphaline' own brand batteries are excellent value and are manufactured by Varta (who also make Bosch batteries incidentally as the parent company is the same).

Edited by r11co on Thursday 23 December 18:42

[TheLurker]

Eurocarparts has always been cheep for me, and they have a decent range too.

[r11co]

TheLurker said:

Eurocarparts has always been cheep for me, and they have a decent range too.

I can't say they were competitive when I was looking around recently - they were one of the sellers doing Bosch Blue for more than a Bosch Silver from Costco!

[steve singh]

Thanks - Costco it is !

Edited by steve singh on Friday 24th December 09:00

[PaulG40]

If you've a halfords trade discount card, try them. It may surprise you.

[Ozzie Osmond]

steve singh said:

The car still starts fine but I'm guessing the battery is on it's way out - it's just a matter of time?

I've always found the green magic eyes hideously unreliable. By which I mean the battery can have years of useful life left when there's no green showing.

If you want peace of mind about your battery go to a specialist battery centre and get them to do a high current drain test. This is the only way to check a battery properly. If you want a DIY check get the battery indoors (charge it if it's not been in regular use) and leave it to stand for a few hours, preferably overnight. Then check the voltage with an accurate voltmeter - the battery must be at normal room temperature for this. If you get less than 12.4 volts your battery is ready for replacement.

Perfect condition = 12.66 volts
75% charge = 12.45 volts
50% charge = 12.24 volts
25% charge = 12.06 volts
Dead = 11.89 volts

[steve singh]

Thanks Ozzie - that's very useful.

I might take it to these free battery testing places.

My thought process was that the battery is fine today, but if the electrolyte levels fall further I'll end up doing some permanant damage to the cells.

[giggity]

+1 for Costsco and the Bosch S5 battery,

Cheapest place I've seen for an S5 and its the top end battery that simply works. Costsco are great if you have any problems too...