Battery issues

[therigsmith]

Hi Guys.

I have trouble with my battery, I replaced it last year but assumed my kids killed it charging phones and leaving lights on. I replaced it yesterday and the new one already seems to be loosing starting power. No one has left anything on this time and the battery is supposedly better quality than the last

Anyways for the last year I have been charging my battery around every two or 3 days. I had to bite the bullet and get a new one because if I drive at night I can not have lights on for long.

I think the Alternator is working but not sure how to test that. I see the voltage rise a bit when its running I will check again when the vans home. But what voltage do I expect for healthy alternator. is it possible to blow a phase or have it part working.

Is there anything else I should check. I was thinking of trying to brake the battery wire, insert amp meter, with the key out and check for excessive Amps that might be draining over night. What kind of idle current do I expect.

The new battery this time advised to me in store 130euros Bateria VARTA E38 Silver Dynamic 74 Ah - 750 A

[vanfox]

Check your battery terminals. If showing signs of green rot replace them. Check the battery earth to the starter motor bolt for tightness and cleanliness. If you think it's draining overnite fit a fully charged battery and fit your ammeter between ground and battery.You should just see the current draw for the radio and pats etc. Hardly anything. You can't "kill" a good battery, only discharge it then recharge it. Engine running should show about 14 volts, engine off, just over 12volts, approx.
Check battery terminals first. Try starting a few times, if they get hot they need replacing.

[gotgcoalman]

supplier of the battery had your trousers down I'm affraid.

By about 40 euros

as said check the wiring first for something obvious.

Healthy battery 12.6v or more.
healthy alternator 14-14.4v

Check charging with tester across the battery and from the alternator to an earth point.
parasitic drain test (this was the easiest to follow)

http://www.wikihow.com/Find-a-Parasitic-Battery-Drain
or video
https://www.youtube.com/watch?v=KF1gijj03_0

[transitjack]

these alternators can charge a bit but not fully once the brushes wear bad
happened to me the other month,i too nearly bought a battery because it was showing a charge but not under load ie lights on
the brushes pack unbolted from my alternator and cost about £8 from ebay,unfortunately i broke one of the brushes halfway down fitting it in but even so full charging has been resumed

[baxi]

i did have an alternator which let the battery down overnight , had to start pulling battery terminal off at night when i parked up . found out it was a diode inside , cheap part but needs a sparky ? .