Are all car battery chargers pretty much the same?

Strider590

Not to be picky but it's 110AH, Amp/Hour...

This means if you sit it on a bench off charge and connect a 1 amp load it will take 110 hours to "die".

Then going the other way it means (not taking into account inherent losses such as heat), it will take 110 hours to charge again at a rate of 1 amp, 55hrs @ 2amp, 27.5hrs @ 4amps, 13.75hrs @ 8amps.

So I guess you'd need to be charging at 64amps to fully charge the battery on a 2 hour run, but then it's winter, the heater/ac is on, the lights are on, etc etc etc.....

2 hours wasn't enough.

reeac

mikey72 wrote: »

The cold cranking capacity is the current a battery can give for 30s, before being discharged. 920A for this battery.

The 110A refers to the capacity, usually measured at 1/10 of an amp, and is a different type of measurement.

I was responding to Strider's statement that it would take a long time to replace the charge used up during a cold start. "Charge used up" means Amp hours and I was giving figures to show how few Ah a starter motor uses. I accept that I forgot about the consumption of glow plugs but not all diesels have them. I have a compact tractor that has them but a Volvo marine diesel that doesn't. Glow plugs use some 10s of amps., say 60A, and are usually used for 10-15 seconds so that's another 0.25 Ah - not earth-shattering and if you have them then the starting takes about 3-4 seconds at most so there's an overall saving on Ah.

mikey72

reeac wrote: »

I was responding to Strider's statement that it would take a long time to replace the charge used up during a cold start. "Charge used up" means Amp hours and I was giving figures to show how few Ah a starter motor uses. I accept that I forgot about the consumption of glow plugs but not all diesels have them. I have a compact tractor that has them but a Volvo marine diesel that doesn't. Glow plugs use some 10s of amps., say 60A, and are usually used for 10-15 seconds so that's another 0.25 Ah - not earth-shattering and if you have them then the starting takes about 3-4 seconds at most so there's an overall saving on Ah.

It's not a true comparison though, as the 920A cold cranking battery can only crank for about 60 seconds before it's completely flat, as it's not a 110Ah battery at a discharge of 500A.
So if you crank for 10 seconds, you've used at least a sixth of the capacity, or say about 20 Ah off the 110Ah charge.
And you need to put that 20Ah back in.

Gloomendoom

britishboy wrote: »

Cheers again mikey,will put her on a long charge for a day or 2 Thursday once Lidl one hits the shelfs, do you know if the Lidl one will kick start my battery if its very flat? Read somewhere smart chargers only top up and keep optimised, and dont have enough ooomph to revive a dead one? Is this true?

The similar Aldi charger I have has a pulse charging facility for very flat batteries but it will only work if the battery still has between 7.5 and 10.5 volts. I believe that if it is less than that you can trick the charger by connecting up another good battery to the dead battery and charging them both. Not tried it myself but the info came from a battery manufacturer.

andy2004

http://www.lidl.co.uk/cps/rde/xchg/lidl_uk/hs.xsl/index_27894.htm

I bought one of these chargers last year, works a treat, can even bring a dead battery back to life. thanks to the way i use my car short journeys stop and start, my battery has to be recharged pretty much once a month, I replaced my dead battery with a another one, and went the same way i thought originally it wasnt getting enough charge, but a trip to the garage and a voltage test from the alternator at 13.3volts told me otherwise, used the above charger on the dead battery, replaced the new one to charge it, and i just swap them over every other month, and it stills working.
Cold weather we have been having also takes out some of the charge.
This charger can also charge the GEL batteries. I can take a scan of the manual, its in the box, and its currently late so i'll post the pic when i do it tomorrow.

reeac

mikey72 wrote: »

It's not a true comparison though, as the 920A cold cranking battery can only crank for about 60 seconds before it's completely flat, as it's not a 110Ah battery at a discharge of 500A.
So if you crank for 10 seconds, you've used at least a sixth of the capacity, or say about 20 Ah off the 110Ah charge.
And you need to put that 20Ah back in.

I don't think that that's how it works. Boats often have a dedicated starter battery and also one or more large capacity "house batteries" and it's often said that, if you have manual switching of the alternator between the batteries, you barely need to bother about recharging the starter battery after a start but should concentrate on the house batter[ies].

I would also challenge the idea that the output of an alternator is low at idling speed - I've never seen any evidence of this judging by headlamp brightness however much other electrical equipment is switched on. It's certainly not like the old dynamo situation.

mikey72

reeac wrote: »

I don't think that that's how it works. Boats often have a dedicated starter battery and also one or more large capacity "house batteries" and it's often said that, if you have manual switching of the alternator between the batteries, you barely need to bother about recharging the starter battery after a start but should concentrate on the house batter[ies].

I would also challenge the idea that the output of an alternator is low at idling speed - I've never seen any evidence of this judging by headlamp brightness however much other electrical equipment is switched on. It's certainly not like the old dynamo situation.

Old alternators had a low output at idle, but still enough to put a small charge back, if that's all it was doing, Modern ones are a lot better at idle. Most give a third to two thirds rates output at idle, so say at least 30 to 60 Amps in this example.
On a cold morning, with the demisters taking 30A, the climate control pulling another 10A, lights pulling 15A, etc, you won't be charging much though.

longwalks1

Right bit of an update gents, thanks for helping out so far

Ran out an extension lead to my car, connected new charger to battery, then charger to ext lead, turned it on and battery charger has power to the 'stand-by' light, but pressing the 'mose' button to cycle through the options (6v, 12v normal, 12v cold conditions etc) it doesnt move from the stand by position, is this because thw battery is possibly completely flat?

Any ideas or help greatly appreciatred as I now need to use the car

Thanks in advance

espresso

britishboy wrote: »

Right bit of an update gents, thanks for helping out so far

Ran out an extension lead to my car, connected new charger to battery, then charger to ext lead, turned it on and battery charger has power to the 'stand-by' light, but pressing the 'mose' button to cycle through the options (6v, 12v normal, 12v cold conditions etc) it doesnt move from the stand by position, is this because thw battery is possibly completely flat?

Any ideas or help greatly appreciatred as I now need to use the car

Thanks in advance

How long have you left it connected?

Regenerating/charging empty (used,overcharged) 12V batteries

The battery charger detects the battery voltage automatically once the battery charger is connected to a battery and the charging process has started. It changes to pulse charging mode if the voltage is in the range of 7.5 V ± 0.5 to 10.5 V ± 0.5 V. This pulse charging process is continued until the battery voltage has increased to 10.5 V ± 0.5 V. As soon as this state is reached, the battery charger switches into the normal charging mode that you selected earlier.

longwalks1

Was connected for about 10 minutes, it just sat there in 'standby' mode, not letting me cycle through the options on it