E30 Zone

How long should a fully charged 12V battery stay charged if it is left in storage.

I'm sorry but that's an impossible question - I have an old Bosch (at least 10 years old, outer casing is dark green plastic) that I can leave for months and it still hold charge, but it's the only battery I've ever had that does.

if its warranty purposes it should be recharged atleast once a year....some have lable on

odd question,why?

if dis charged for around 6 months and a lead battery dies and you cant use it again as the plates get to covered up.

I've got a optima yellow top in my lock-up that's just been sitting there for well over a year - still test 12v with a meter

I've also got another yellow top that's been there the same amount of time and is proper dead

Car batteries always seem a bit random to me!!

miniblob wrote:I've got a optima yellow top in my lock-up that's just been sitting there for well over a year - still test 12v with a meter

Yes but how are the amps? (If Im thinking of the right thing).

Our boat battery was left for a winter in the boat (my mistake). It still tested at 12v, but even after a charge it couldnt crank the engine over. Had it tested properly and it showed around 12v but totally dead when cranking.

If youre storing a battery, dont leave it directly on a concrete floor - seems to drain them for some reason. A nice block of wood does the trick, sections of 2x6 flooring joists come in handy.

Just gonna go and move it off that concrete floor now!!!!
The dead one was on the concrete and the other was on top of some other stuff actually - weird!!

No idea how good it is yet!! Gotta get off my arse and wire it in as a second battery - then when i get my sounds in i'll prob have to buy a replacement for it!! Didn't really think about that!!

Is there a proper way of testing how good a battery is??

test by sg or drop test.

use hydrometer or drop tester

Woah, something just flew over my head!!!!!

Perhaps i'll just whack it in the car and see if it starts it!!

No idea what either of those two are mate - sorry!!

drop basically a heavy load test with some kind of voltmeter/state indicator...
hydrometers check specific gravity...usually have a guage on....handy tool to have...cheap too-

http://cgi.ebay.co.uk/Battery-Hydromete ... dZViewItem


http://cgi.ebay.co.uk/SEALEY-Battery-Dr ... dZViewItem

Take it to a garage or motorfactors (maybe even Halfrauds). They should have a tester that shows it all.

jmc330i wrote:Take it to a garage or motorfactors (maybe even Halfrauds). They should have a tester that shows it all.

probably will have but they wont tell you why its failed or if your alternater is dying.....or do you have a more intelligent type of salesperson in your stores...lol

plus if you buy your own you may catch it before it lets you down....


i check charge systems and battery condition on all services i do-also look after a lot or traction batteries so ive got the above type of kit,but those ive linked to ebay are good enough for the diy mechanic..

Cheers for that, might invest in those little tools at some point!!

One of the batteries I have seems to be knackered.

I charged it up last week and its flat already 11.01V 5A
while the other is a constant 12.5V ???A

gcorky wrote:

jmc330i wrote:Take it to a garage or motorfactors (maybe even Halfrauds). They should have a tester that shows it all.

probably will have but they wont tell you why its failed or if your alternater is dying.....or do you have a more intelligent type of salesperson in your stores...lol

plus if you buy your own you may catch it before it lets you down....


i check charge systems and battery condition on all services i do-also look after a lot or traction batteries so ive got the above type of kit,but those ive linked to ebay are good enough for the diy mechanic..

Yeah, sorry I just meant taking the battery in to see if it is knackered. With our boat battery, it was fully charged, but wouldnt crank the engine and the only tester we had showed good at 12v (ish). Took it to a local motor factors who stuck their tester on it and said yes its got 12v but no amps - its dead.

Agreed those testers you pointed out will be a good idea so you can keep an eye on things, so you dont end up with a knackered battery.

i use a diesel van battery on my car due to all my ancillaries and have two 7 & 1/2 tonne truck batterys feeding my install

anyone know where i can dispose of the dead one ? (North East area)

(joking) - Grimsby High Street; no-one would notice....

(serious) - any Tip/Household waste place - down here they stack them up under cover, and send them off somewhere for proper recycling.

smithy318i wrote:anyone know where i can dispose of the dead one ? (North East area)

We get the recycling trucks come by ever other week and we can leave them out to be collected by them.

FYI

Concrete (specially new concrete) emits gammaenergy which affects the batteries. It is almost as radiating as the welding pins on those old cathode welders...

Gurgli