Technical Battery testing how hard can it be

[MrMagoo]

I agree excessive restarting over small distances would have a detrimental affect on battery performance and one may sense the loss the decline in starting enablement, but I only moved my works vehicle once over a weekend!
Anyway, AA chap said my original depleted battery needed a 45 minute drive to recharge it but then decided to replace it, and as a bonus now my stop/start works too!

 

[vexorg]

Leaving it for longer periods will also degrade the battery, particularly on new cars that have a constant low load slowly draining them.

I'd go with 45minutes if you have it in daily use, however leave it a week again then I'd have my doubt on it starting.
Also depends on the battery age, a new battery run flat will recover quickly, and old battery you'd have doubt as running them right down can have permanent effects.

 

[koalar]

Battery testing how hard can it be?​

It appears difficult for the Halfords and AA techs to check my weak battery in my company vehicle.
Halfords tech didn't know how to use his kit.
AA tech said I need to drive my vehicle for at least 15 minutes every time I start it. I replied I've been driving for over 30 years and I never heard anything so ridiculous; he replaced the battery.

I don’t think Halfords employ people on average that have much experience.

Crewe they tried to fit a windscreen wiper for 1/2 hour. Norwich they also fitted the wrong capacity battery to my sisters diesel

There’s too many variables (temperature, crank time, what accessories are on)to work out how long it takes to replace the energy taken from the battery during cranking to be replaced by the alternator

Can’t be long on average otherwise start stop technology wouldn’t have been invented

In winter a drive of just less than 3 miles in about 10 minutes with lights on and blowers on 1 then 2 is fine

Post office vans seem fine.

 

[koalar]

Leaving it for longer periods will also degrade the battery, particularly on new cars that have a constant low load slowly draining them.

Shorten its life considerably

Used daily 15 years is not unheard of.

I'd go with 45minutes if you have it in daily use, however leave it a week again then I'd have my doubt on it starting.
Also depends on the battery age, a new battery run flat will recover quickly, and old battery you'd have doubt as running them right down can have permanent effects.

One 80 mile round trip once a fortnight in summer is fine. I doubt anyone knows the absolute limit is

 

[DaveMcT]

An Optimate charger costs about £60 and will keep a battery topped up without "boiling-off" the acid. They are generally sold for motorcycles so will be even more gentle on a car battery. It depends whether the hassle of connecting it (and not forgetting to disconnect) is worth the cost of a new battery every three to five years.

My Optimate has recovered a few flat car batteries, but they all had minimal usable capacity and had to be replaced anyway. It's never been used for regular battery conditioning on my cars but it clearly could be.

 

[bugsymike]

An Optimate charger costs about £60 and will keep a battery topped up without "boiling-off" the acid. They are generally sold for motorcycles so will be even more gentle on a car battery. It depends whether the hassle of connecting it (and not forgetting to disconnect) is worth the cost of a new battery every three to five years.

My Optimate has recovered a few flat car batteries, but they all had minimal usable capacity and had to be replaced anyway. It's never been used for regular battery conditioning on my cars but it clearly could be.

I use a cheap Chinese charger with a repair function which generally does the job, I have a SIP garage 500Amp Booster Start/Charge , but haven't needed it for years and finally I have a Ring Battery System Analyser which generally seems accurate to tell if a battery is recoverable or scrap on % of original capacity by the code on the battery.

 

[vexorg]

One 80 mile round trip once a fortnight in summer is fine. I doubt anyone knows the absolute limit is

I was meaning 45 minutes from completely flat, and then leaving it a week.