Pudsey Bear
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YMMV ???
Engine battery 0 volts
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2cv
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Meaning of YMMV in Englishwritten abbreviation for your mileage may vary: used, for example on social media and in text messages and emails, to mean that you understand people may have a different opinion or experience to yours: Their first album is better, but of course YMMV.
Pudsey Bear
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The second replacement Ctek arrived on Thursday, I connected it up and it is still only putting out 13.2v.
Ctek say it should put out 14.2v.
Another thing, I bought a new ciggy socket voltage display as I wasn't 100% sure of the old one, they both do the same thing though when I turn on the sign, they show 11.9v then it slowly climbs up to 13.2v after about 5 minutes, and off charge again slowly up to 12.4/5/6v
The manual isn't very good
file:///C:/Users/dell/Dropbox/Van%20stuff/PDFs%20for%20Ben/CTEK_MXS5_User_Manual.pdf
Ctek say it should put out 14.2v.
Another thing, I bought a new ciggy socket voltage display as I wasn't 100% sure of the old one, they both do the same thing though when I turn on the sign, they show 11.9v then it slowly climbs up to 13.2v after about 5 minutes, and off charge again slowly up to 12.4/5/6v
The manual isn't very good
file:///C:/Users/dell/Dropbox/Van%20stuff/PDFs%20for%20Ben/CTEK_MXS5_User_Manual.pdf
trevskoda
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You must leave the charger on over night to let the voltage rise, also make sure something is not drawing current away, could also be a duff diode in the alt, get it tasted.
Pudsey Bear
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It's been on since Thursday, as said ign on, it goes up over 14v if I start the engine, and I am not tasting anything.
Geek
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A smart charger wil not put out a set voltage. That's what dumb chargers do.
A smart charger will have four stages.
First it will slowly charge the battery until it reaches about 12.8v.
At that point it will switch to bulk charge, where it puts out its rated current until the voltage rises to about 14.4v.
At that point it will hold the voltage constant, and depending on the design, keep charging at that voltage for a set time or until the charge current drops to a set value.
*See note below
At that point, it backs off and holds the voltage at about 13.4v indefinitely.
*Note
Some chargers have an additional balancing phase, where they bring the voltage up to a bit over 15v. Usually they only do this every few months. This phase must be disabled for a lithium battery.
An alternator, on the other hand, simply belts out 14.4v for an hour or so, then drops back to 13.8v.
So just looking at the voltage is no way to assess a smart charger's performance.
A smart charger will have four stages.
First it will slowly charge the battery until it reaches about 12.8v.
At that point it will switch to bulk charge, where it puts out its rated current until the voltage rises to about 14.4v.
At that point it will hold the voltage constant, and depending on the design, keep charging at that voltage for a set time or until the charge current drops to a set value.
*See note below
At that point, it backs off and holds the voltage at about 13.4v indefinitely.
*Note
Some chargers have an additional balancing phase, where they bring the voltage up to a bit over 15v. Usually they only do this every few months. This phase must be disabled for a lithium battery.
An alternator, on the other hand, simply belts out 14.4v for an hour or so, then drops back to 13.8v.
So just looking at the voltage is no way to assess a smart charger's performance.
wildebus
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Pudsey Bear
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I'm just a bit wary, the Ctek having died once and according the their tech the replacement not performing as it should but this one is exactly the same it is looking like I have a spare now, they asked me to cut both leads off the original one but not the second, I'm happy that the display is reading over 12.5v, just curious as to why it takes a while to get to that figure.
The new battery was at 11.9v when it arrived so not suspecting a problem there.
The new battery was at 11.9v when it arrived so not suspecting a problem there.
trevskoda
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Pudsey Bear
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Actually Tom the battery arrived mid week and I had someone fit it at the weekend.
Pudsey Bear
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I have three, but there is not easy access point for the VB
Geek
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Geek
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That chart isn't relevant for a battery not being discharged (which is what this discussion is about), but it's interesting, nonetheless.
It suggests that a fully charged 100Ah battery will have a voltage of about 12.7v at rest, 12.65 when giving 5A of current.
The same battery at 50% SOC will still be at 12.7v at rest and at 12.4v when giving 5A of current.
Take 20A out and the voltage will be 12.1v when it is fully charged or 11.55v when 50% discharged.
Geek
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You can test at any point if there is nothing switched on. There will be no voltage drop in the wiring if there is no current.
trevskoda
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Used them for years in garages i worked in, always done the trick, we did voltage tests on a crypton tunner.
Truth is many so called lez batts are no more than a sticker on the front saying so, yes i know they are ment to have thicker plats, many dont.
Geek
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They are fine for use in a garage, testing a starter battery's ability to start an engine.
I used them in the garage where I worked - the old glowing strip sort that you could burn yourself on.
I have one of the modern digital ones now. I use it for checking starter batteries, but they are not testing the right thing for this.