Charging Battery

[andygill]

Hi

If I want to charge my battery whilst leaving it in the car do I need to disconnect it from the car.

Thanks
Andy

[bmcecosse]

No - but if it's a 'high rate' starter/charger machine - they have been known to damage the alternator.

[rayofleamington]

A fast rate charger won't damage a dynamo, but yes an alternator is less robust and can be damaged by voltage spikes etc...

I use a slow rate charger on lots of cars, including moderns and Minors without disconnecting the battery. To avoid spikes it is best to connect the charger to the battery before you turn it on.

[andygill]

I stored by traveller in a garage for 5 months foolishly without disconnecting the battery.

Obviously it was dead when I came to try it.

I charged it and the car ran fine for a couple of days.

However on a couple of occasions since the weekend if I haven't used the car for 24 hours it won't start.

First time was on Saturday. I charged the batter for an hour and it ran fine.

This morning the car again wouldn't start. (I haven't charged it yet).

Does it sound like I have damaged the battery by originally not disconnecting it.

Thanks
Andy

[Stig]

The battery may well be damaged due to being left flat. I doubt disconnecting it would have made any difference unless you've got an alarm, clock etc. that takes current when the ignition's off, what it needed was charging from time to time. I did the same with my Sprite over winter and the battery's capacity seems to have suffered somewhat.

If anyone knows a magic trick/potion to revive it please tell. What about EDTA, anyone used it?

[Neil MG]

Yes it does sound like that finally killed the battery, but there are a few checks you can do before rushing out and buying a new one, if you have a good digital voltmeter. First charge the battery up fully (about 12.6V) and either leave for a few hours or turn the lights on for five minutes, turn them off and wait five minutes. Check again and you should still have about 12.5V or more.

In my experience any values that are significantly below these mean that your battery is ready for replacement.

[andygill]

Can anyone recommend a new battery for a traveller ?

[ASL642]

Any local to you motor spares shop/Halfords etc. Don't get the cheapest as it's false economy, especially if you have an alternator, and intend to drive at night with the mp3 player going and have a cigarette lighter installed for the mobile phone! Good standard 12v will do.

[andygill]

Any local to you motor spares shop/Halfords etc. Don't get the cheapest as it's false economy, especially if you have an alternator, and intend to drive at night with the mp3 player going and have a cigarette lighter installed for the mobile phone! Good standard 12v will do.

Thanks for the reply Lou

When you say don't go for the cheapest do you mean the cheapest with the same spec or go for a higher spec. Do I need a 12v 038 ?

Sorry I don't know anything about them.

[ASL642]

Sorry wasn't clear enough. I meant don't buy the cheapest i.e £30 job. An 038 should do the job It's usually listed un Old Rover in Halfords.

[chrisryder]

top tip: check the terminals are the right way around! the halfords 038 battery has the terminals the right way around for us, most other batteries are opposite. although i have killed a few halfords ones, so an 038 might not be the best quality!

general consensus i've heard is get the biggest that'll fit in the battery box. so measure your battery box, and take a tape measure when you go to buy a battery!

[chrisryder]

also, on the charging front:
[frame][/frame]


not sure why this blew up. it was on my dads minor, which had a flat battery. so we put the charger on it. left it for a while, disconnected the charger. start the engine. BANG.

acid everywhere. battery casing everywhere.

very lucky he didnt start it with the push button under the bonnet.

any ideas why it blew? our best guess is gas from the charging process, followed by a short between plates when starting. short = spark. spark + gas = bang

[rayofleamington]

what age is the car? The earlier cars have a pull switch on the bulkhead near the battery (later ones have a solenoid on the bulkhead crossmember) - if there was a lot of hydrogen around from charging it could have been ignited by the starter switch!

These blown up batteries are very rare but they do happen - as your picture shows!!

Even the spark from removing a charger lead can cause an explosion - therefore the charger should be powered down before you touch the croc clips. I've seen advise about waiting 15 minutes before using the car - until now I'd guessed that was a waste of time

[chrisryder]

i'd never worried about a battery exploding before, and have charged numerous ones in the same manner before without thought.

since that one went bang. i'm so careful i laugh at myself for being so fearful. the odds of it happening again are very low, but it doesnt stop me from disconnecting the charger whilst facing away from the battery (to protect my face) and shutting the bonnet before trying to start the engine to save chunks flying 10m away like that one did!

it was, as you said, a pull start minor, with the switch up on the bulkhead near the battery itself. perhaps that was the trigger.

i make sure to always turn the charger on/off at the wall rather than having live leads floating around when connecting or disconnecting.

are you supposed to remove the filling caps on a battery while charging to allow it to vent? we hadn't on this occasion, and we never usually bother.

[bmcecosse]

Back to the original subject - before buying a battery, check if it is being charged by the dynamo/alternator when running. And check for any 'drain' on the battery when the car is standing. A £10 solar charger connected over the winter would have saved all this trouble. Both my cars awakened after the long winter with fully charged/operational batteries - and the batteries in both are far from new - or large. The TR7 (2 litre motor) has the smallest battery available - but it cranks it up no problem at all. My advice - buy a small/cheap battery, and look after it properly!

[MarkyB]

put the charger on it. left it for a while

I suspect it was a "fast" charger, these are as good for a battery as an over charging alternator, they will boil the battery which does it no favours.