why does my battery sometimes go flat in the rain?

About 6 weeks ago I went on a 50k round trip. When I left it was raining, I got home unloaded the car and went in. Next morning the battery was flat as a pancake.

Yesterday I did the same trip. Today I went about 1k to the shops. It was raining slightly.
When I tried to start the car, the radio came on but the engine just went click. I tried a couple more times and the radio went dead. I waited a minute or so and the radio came back on but still no start, just the clicking. The radio went dead. When it came back on I tried the lights but they were not working although the dash panel lights were on. Conclusion not enough juice to power lights but radio and panel yes.

I can take the battery home and charge it but I don't want this to happen again and don't know what to look for.

Never heard of rain causing a battery to go flat.... sounds like alternator on its way out. Cause ur travelling a longer distance and the battery isnt getting enough or isnt charging then this is why it dies. I would be starting there first

No the rain per say wouldn't cause the battery to go flat but it could help to short it out somehow.
The fact the radio would be dead and then come on again when I turn the ignition off but with loss of settings means one minute there is power and then the next none. Not the sign of a flat battery surely, more sign of a short somewhere thus causing the battery to flatten?

I am going to go get the battery and bring it home and put it on charge. At least then I will know if the battery is actually flat or not.

I got the battery home (a friend pulled up just as I was about to walk home, it must be xmas or something) and put it on charge. It isn't totally flat like last time but it isn't fully charged.

I was just wondering if the starter motor or solenoid is stuck one can tr turning the engine over by hand to release it. I just used to put a thumb on the fan belt and turn the fan but can't do that on this as there isn't one. S do you put a wrench on the big nut on the alternator to turn it over?

Are both battery terminals good and clean and the connectors that go on them must be clean and tight too.
Check for good connections where the negative connection screws on to the body, and where the positive wire connects to the solenoid..

Well the battery was half charged when I got home and put it on. That isn't enough to start it I know from the last time.
This morning I put back in the car and it started first time as usual.

I still think it is something to do with the rain shorting it out because the last time this happened was 6 weeks ago and in between I do a two or three small trips almost every day so if the battery wasn't charging or holding the charge I would be having this problem every couple of days.

Oh well it's working now so wait till next time and hope I am close to home again.

how old is the battery

one thing i learned was a battery can have 12 volts but no cranking amps

have a trusted mechanic do a battery load test
then check the alternator charge
go from there

i had a battery that showed 13 volts would charge to that
but could only get one good crank out of it
i just went ahead and got a new battery to save me stress

Battery capacity decreases as it ages. I had a battery once that cranked and started the car fine, but if I had the headlights on for a couple of minutes first, it wouldn't start the car. It's a good test to do to see if your battery is getting to end-of-life.

Being a cheapskate at the time I carried a spare good battery around while I waited for the tired battery to die. lol Took a couple of weeks.

A multimeter across the battery while the lights are on will show rapidly decreasing voltage. Something else to look for.

Such a low capacity battery will appear to charge up really quickly, too. Something to watch out for as well.

A couple of short trips a day should keep the battery charged, as long as the alternator and battery are in good order.

Thanks for the tips Magna Buff and Mad Max. That was my next question how do I check if it is battery or alternator.

I have had the car for about 2 1/2 years but it's only been on the road for 1 year. I always thought if the battery were going flat it give me an errr errrr errrr umph sound when trying to start it but nope.

The reason I have a battery charger is because you need one when you are driving old second hand cars lol. I always had one when I lived in the UK and bought this one thirty years ago when I got to Aus. I have only used it about a dozen times but without it life would be a lot more expensive.
It's another reason I only like to drive manuals, at least you can bump start them easily. Not the magna though. Trying to push it without the engine going is like trying to push a bulldozer.

What do ou gus think of one of these http://www.ebay.com.au/itm/BRAND-NEW-PORTABLE-12-VOLT-900-AMP-CAR-BATTERY-JUMP-STARTER/251336595623?_trksid=p2045573.m2042&_trkparms=aid%3D111000%26algo%3DREC.CURRENT%26ao%3 D1%26asc%3D27%26meid%3D3686243201255730857%26pid%3 D100033%26prg%3D1011%26rk%3D3%26rkt%3D4%26sd%3D261 152185378%26

Are they as good as they sound?

Yes, that sounds pretty reasonable for the price..Get the waterproof model though !
And if you still have to push it, at least you can pump the tires up first :D

Thanks for the tips Magna Buff and Mad Max. That was my next question how do I check if it is battery or alternator.

I have had the car for about 2 1/2 years but it's only been on the road for 1 year. I always thought if the battery were going flat it give me an errr errrr errrr umph sound when trying to start it but nope.

The reason I have a battery charger is because you need one when you are driving old second hand cars lol. I always had one when I lived in the UK and bought this one thirty years ago when I got to Aus. I have only used it about a dozen times but without it life would be a lot more expensive.
It's another reason I only like to drive manuals, at least you can bump start them easily. Not the magna though. Trying to push it without the engine going is like trying to push a bulldozer.

What do ou gus think of one of these http://www.ebay.com.au/itm/BRAND-NEW-PORTABLE-12-VOLT-900-AMP-CAR-BATTERY-JUMP-STARTER/251336595623?_trksid=p2045573.m2042&_trkparms=aid%3D111000%26algo%3DREC.CURRENT%26ao%3 D1%26asc%3D27%26meid%3D3686243201255730857%26pid%3 D100033%26prg%3D1011%26rk%3D3%26rkt%3D4%26sd%3D261 152185378%26

Are they as good as they sound?
My missus bought me one of those from same same seller, it crapped itself within 3 months, got a replacment after many arguments via email which crapped out in 2 weeks, maybe I got the ones that were made on a monday, but never again.

My missus bought me one of those from same same seller, it crapped itself within 3 months, got a replacment after many arguments via email which crapped out in 2 weeks, maybe I got the ones that were made on a monday, but never again.
Thanks Harry, That's what I was thinking. I just thought something like that would be nice to have in the car next time I go fishing cause I wouldn't like to walk miles to find a bus stop.
I won't bother with that particular model now though.

could we fix the problem so you dont need a battery charger

new readers might think second gens magnas
have something wrong with them
we all know different .....they are fixable

buy the jump starter locally keep the reciept so you can take it back

sarah asks how to know if its battery or alternator.

To check alternator:
with the car idling at normal idle speed, note the sound of the engine and its speed. Then, turn the headlights on full beam, and if the engine slows down, then you can be sure the extra loading of the engine is caused by the alternator supplying the head lamp load. If however, the engine doesnt slow down, AND the dash board lights dim slightly, then you can be sure the alternator is not supplying any load to the head lamps, and is therefore faulty.

With batteries, they can stuff up within 24 hours for NO apparent reason. BUT, when an engine seems 'difficult to crank', it is not always due to a dodgy battery. Fault finding in this situation needs some reasonably good knowledge of how to proceed. The simplest way to check a battery, is to measure the terminal voltage with a voltmeter WHILE THE ENGINE IS BEING CRANKED. The voltage should be more than about 7 to 8 volt. This test is best done with an analog voltmeter. A digital voltmeter may give readings which are difficult to interpret.
Hope this helps.

could we fix the problem so you dont need a battery charger

+1

I junked my jump cables for this reason. I'd rather fix any problems before a charger or jumper cables are needed.

5 minutes with a multimeter is all I need to find out if the battery and alternator are 100%.

(I do have a charger, does 20A --> 3A --> trickle charge, very useful for a battery in storage.)

Thanks everyone for the tips. Yes magnabuff I would prefer to fix the problem but that is going to take money I don't have. I don't own a multimeter and wouldn't know what I was doing if I did own one. That means someone checking the alternator and battery and they won't do it for free will they?
I don't have money to spend buying the battery only to find it was the alternator. I need to get it right first time.

I was talking about the battery starter because I thought it would be a good thing to have when I am out miles from anywhere. It's like insurance, if you have it ou don't usually need to use it.

When you buy a second hand car you rarely know how old the battery is or when it is going to go which is why the charger. If it does go a charge is enough to pick the car up and get it home. Like I said I didn't get a warning it just went but after a charge I am still driving it, just not too far from home. Payday is soon and now I have to choose between flea treatment for the dog, a battery or an alternator.

But yeah I love my car, these things that are going wrong are the same things that go wrong for any car of a similar age. People look at it from the outside, all scratched and a sun faded roof and bonnet. But it's like when someone enters the Tardis for the first time. It's bigger on the inside than it looks on the outside, and very comfortable. More leg room and head room and very comfy seats.

dont want you to get ripped off

this is a start hope you can afford this.... and the dog flea treatment

http://www.ebay.com.au/itm/LCD-DIGITAL-MULTIMETER-AC-DC-VOLTMETER-OHMMETER-AMMETER-ELECTRICAL-TESTER-/321254585900

how to use one

http://www.doctronics.co.uk/meter.htm

if you have any questions at all just post ok

dont want you to get ripped off

this is a start hope you can afford this.... and the dog flea treatment

http://www.ebay.com.au/itm/LCD-DIGITAL-MULTIMETER-AC-DC-VOLTMETER-OHMMETER-AMMETER-ELECTRICAL-TESTER-/321254585900

how to use one

http://www.doctronics.co.uk/meter.htm

if you have any questions at all just post ok

Well that's not a bad price at all, won't hurt, but come on homework? I failed physics 44 years ago but I can change a plug.
The diagrams don't mention anything about alternators but I did see the word battery once or twice. I am sure I will have more questions but not 'til Thursday at least.

Thanks guys have a good one.

if you go to buy that multimeter instructions are as follows, plug the red cable in to the bottom port of the multimeter, then plug the black cable in the middle port of the multimter. turn the dial to the left of "off" to 20, start car, put the pointy end of the red lead to the positive of the battery, and the pointy end of the black lead to the negative side of the battery. should read 14.4 or there a bouts, if it reads 13.5 or under your alternator/regulator is at fault. turn the car off, get a friend to then start the car again while you look at the multimeter, if it drops under 10 when the car cranks the battery is no good.

the unit needs a battery .... mine uses a little square 9 volt battery
should already be fitted

if one comes with it and not fitted
all you need is a jewelers screwdriver
to undo the two screws in the back if the tester
you cant muck up the polarity it only fits one way

the red cable goes in to the top hole on the right
the black cable goes just below it
you then put the dial to V 20 thats a few clicks to the left

the numbers 0.00 will come up

if you can fit spark plugs you can definatly do this test for your self

the tester is ready to use

read post above

it will give you the numbers as volts

post us the numbers you get

after use ......make sure dial is in off position (battery in tester may go flat)

I have been using the car with no problems since the last post. Even went fishing again a few weeks ago and haven't needed to charge the battery since returning.
But didn't need the lights on when I came home.

I am posting because when I have the wheel almost on hard lock and accelerate there is a screaming noise seems to be coming from the alternator.

Any ideas?

Most probably the power steering drive belt is a bit loose and needs adjusting or if worn/split replacing.

Cheers

on a four cyl
the alternator above the power steering . use the same belt
if no better after adjusting tension or replacing the belt

use a screwdriver or a stick place it on the pump and the alternator in turn
saftley(dont get hair/hands in the way etc )
put other end to your ear....... what do you hear

car working better ..you scared it
no tester needed
I didnt get invitation to fishing trip
:yeahthat:

I didnt get invitation to fishing trip
:yeahthat:
Well now the kids are back at school again I was going to go today until the clutch went yesterday :(