RichardS
N/A
I think something else must have been involved. A normal lead acid battery, sealed or open, should be fine at 14.0V as it is below the gassing voltage, provided that the 14.0V measurement is accurate.
Richard
Great battery charger at Aldi - £12.99
- Thread starter RichardS
- Start date
I think something else must have been involved. A normal lead acid battery, sealed or open, should be fine at 14.0V as it is below the gassing voltage, provided that the 14.0V measurement is accurate.
Richard
lw395
Well-Known Member
What would Varta, Exide, Yuasa, etc etc etc know anyway?
RichardS
N/A
lw395
Well-Known Member
Even the RIB battery is softly fizzing away at the thick end of 15V now.
Does that matter?
It seems that one coulomb of charge electrolyses about 93 microgrammes of water, so guessing the excess current at 50mA, that's
50x93x10^-9 g/s = 4.65 micro gr per second, or about half a gramme of water per day, per cell
The min to max range for a bike battery is about 15cc maximum.
Doesn't look good for leaving it on all winter!
Does that matter?
It seems that one coulomb of charge electrolyses about 93 microgrammes of water, so guessing the excess current at 50mA, that's
50x93x10^-9 g/s = 4.65 micro gr per second, or about half a gramme of water per day, per cell
The min to max range for a bike battery is about 15cc maximum.
Doesn't look good for leaving it on all winter!
RichardS
N/A
Is the charger showing that charge is still going in i.e. the battery symbol is still flashing?
If it's at 15V and still charging it will be gassing 'cos it should have dropped into float mode by now.
I've tried mine one two different batteries and both times it's reached 14.4V (or something close to that), the symbol has stopped flashing, and the battery starts gradually dropping back below the gassing voltage. It's now continuously connected to one of the batteries and that was down to 14.2V when I looked yesterday.
If yours is holding at 15V, it will keep gassing, which is not right so it sounds as if it is faulty. I would take it back and they will exchange it for another one.
Richard
lw395
Well-Known Member
I bought two, both do the same give or take.
It's putting out the 70mA or whatever that the instruction booklet says it does in float mode.
The display indicates it is in float mode.
It has gone through the stages in both 0.8A and 3.8A modes.
Just checked the booklet, the float mode is 'from 50 to 150mA' to keep the battery 'at the fully charged level'.
Trouble is, the battery only wants about 20mA in long term float mode.
I think these are fine little battery charges. Great for dealing with a flat battery or charging something that's in cyclic use.
For £26 the pair, that's great.
I can make use of them.
It's worth having at least one for when people ask to borrow a battery charger and I don't want to set them loose with a cobbled-together thing that you need to be the builder of to use!
They are at the end of the day, battery chargers, not winter battery float maintenance systems.
I don't think they are right for long term, unsupervised maintenance, but to be fair, Aldi never claimed that.
Which is a shame, but c'est la vie.
Some batteries might be happy on them, or if you've got an alarm or something using a watt or so, you might be OK.
The caveat is that they are saying in the isnstructions 'disconnect the battery earth'. I.e., no claim that it's OK to connect them to a vehicle. Unlike the Ctek, which is designed for this. I don't have time or inclination to drag a scope down there and look at the output waveforms to see whether it might upset a vehicle.
And I'm resisting the urge to take one apart!
The equaivalent size Ctek is from £56 to be fair.
About the same price as a new battery for the bike.
It's putting out the 70mA or whatever that the instruction booklet says it does in float mode.
The display indicates it is in float mode.
It has gone through the stages in both 0.8A and 3.8A modes.
Just checked the booklet, the float mode is 'from 50 to 150mA' to keep the battery 'at the fully charged level'.
Trouble is, the battery only wants about 20mA in long term float mode.
I think these are fine little battery charges. Great for dealing with a flat battery or charging something that's in cyclic use.
For £26 the pair, that's great.
I can make use of them.
It's worth having at least one for when people ask to borrow a battery charger and I don't want to set them loose with a cobbled-together thing that you need to be the builder of to use!
They are at the end of the day, battery chargers, not winter battery float maintenance systems.
I don't think they are right for long term, unsupervised maintenance, but to be fair, Aldi never claimed that.
Which is a shame, but c'est la vie.
Some batteries might be happy on them, or if you've got an alarm or something using a watt or so, you might be OK.
The caveat is that they are saying in the isnstructions 'disconnect the battery earth'. I.e., no claim that it's OK to connect them to a vehicle. Unlike the Ctek, which is designed for this. I don't have time or inclination to drag a scope down there and look at the output waveforms to see whether it might upset a vehicle.
And I'm resisting the urge to take one apart!
The equaivalent size Ctek is from £56 to be fair.
About the same price as a new battery for the bike.
Norman_E
Well-Known Member
Just for maintaining a car battery I think that this is probably a better idea: https://www.ebay.co.uk/itm/AA-Car-E...a=0&pg=2047675&_trksid=p2047675.c100005.m1851
I found the PDF instructions here, https://images-eu.ssl-images-amazon.com/images/I/91AENKGFhsS.pdf which show that it restarts in the same mode after a mains power loss.
I found the PDF instructions here, https://images-eu.ssl-images-amazon.com/images/I/91AENKGFhsS.pdf which show that it restarts in the same mode after a mains power loss.
lw395
Well-Known Member
If this:
https://www.ebay.co.uk/itm/Smart-12...a=0&pg=2047675&_trksid=p2047675.c100005.m1851
does what it claims, then it looks like a bargain.
And it's made in the UK! £14.95.
'Oxford' sell/have sold a range of battery maintainers exactly targetted at motorbikes over winter. I think they are a little cheaper than ctek.
I'm still tempted to just put a 1W 12V led bulb across the battery to soak up the excess milliamps of the Aldi charger, but of course that will flatten the battery if the mains goes off.
I can design a circuit to get around that, but it's getting silly.
I could power the Aldi chargers from a timer switch so they only come on for a few hours a week.....
https://www.ebay.co.uk/itm/Smart-12...a=0&pg=2047675&_trksid=p2047675.c100005.m1851
does what it claims, then it looks like a bargain.
And it's made in the UK! £14.95.
'Oxford' sell/have sold a range of battery maintainers exactly targetted at motorbikes over winter. I think they are a little cheaper than ctek.
I'm still tempted to just put a 1W 12V led bulb across the battery to soak up the excess milliamps of the Aldi charger, but of course that will flatten the battery if the mains goes off.
I can design a circuit to get around that, but it's getting silly.
I could power the Aldi chargers from a timer switch so they only come on for a few hours a week.....
peteK
Well-Known Member
It says in the advert only suitable for 2.4 to 8.4amp hrs batteries.
lw395
Well-Known Member
Well spotted.
I have 6Ah battery to maintain on a small bike.
Looking at the description of the charge sequence, what will it do if faced with a bigger battery?
Charge Stages:-
Stage 1 ------ Soft start
Stage 2 ------ Low voltage recovery mode with desulphation feature
Stage 3 ------ Maximum current (bulk charge)
Stage 4 ------ Absorption charge with reducing current
Stage 5 ------ Proportional timed charge mode to bring the battery to 100% charge (14.5V)
Stage 6 ------ Float charge mode to maintain the battery at full charge (13.6V)
I guess it might make stage 5 too long or short?
So long as it gets to 13.6V it ought to be OK, but it might go into float too early, if presented with a well discharged large battery?
And if the mains keeps going on and off, it might possibly spend too much time at too high a voltage?
RichardS
N/A
I've been messing around with my Aldi charger in the garage today and you're right that there is something strange going on.
On one new battery, still connected to a car, the charger reads around 14.3V and has for a week or so. I would be happy with this but when I measure the actual voltage across the battery terminals, the voltage reads above 15V. Although I can't hear any fizzing, this is a higher voltage than I'm happy with long term.
A then tried the charger on another 100Ah but this time one around 10 years old. This time it read around 14.1V once it had gone into float but the actual voltage reads around 14.6V which is still a bit high but not the end of the world.
I don't think this can be a simple error in the voltage reading as it's so far out ..... but it makes me wonder what voltage the charger is actually measuring?
I'm guessing that the 15V you referred to is the actual voltage you measured rather than the displayed voltage? It would be interesting to hear what actual voltages other forumites are finding once the charger is in float/trickle mode.
Richard
lw395
Well-Known Member
TBH I've decided it's a handy device for charging batteries, not a battery maintainer to be permanently connected.
At the price I'm not complaining!
When voltmeters disagree with one another, I generally reach for a scope or press the 'AC' button in case one is reading RMS, the other peak, mean, what have you.
I may get around to setting Mr Tektronix on it, but things are a bit shambolic right now, which is why I wanted a 26 quid fix in the first place.
At the price I'm not complaining!
When voltmeters disagree with one another, I generally reach for a scope or press the 'AC' button in case one is reading RMS, the other peak, mean, what have you.
I may get around to setting Mr Tektronix on it, but things are a bit shambolic right now, which is why I wanted a 26 quid fix in the first place.
RichardS
N/A
It's just a digital multimeter although it's always been accurate when used previously. I did try the AC setting but it just read 0V.
If you remove the charger when the battery is reading 15V, the actual battery voltage drops down to around 13.8 - 14.0V in five seconds. This is the voltage I would expect to see when the charger is connected but as soon as it is connected, the voltage rises again.
I've played around with dozens of chargers over the years but this appears to be an odd one.
Richard
lw395
Well-Known Member
Reading 0V on AC indicates that the voltage is a steady DC voltage. Not a stream of pulses or some other waveform.
If two meters disagree, it's often because there is a pulse/ripple/noise voltage wavefrom imposed on top of the DC level and different meters average it in different ways. So if two meters disagree about the DC value by say 200mV, switching to AC and seeing more than a few mV would explain that and tell me 'if you really want to know, have a look on a scope'.
Some battery chargers doing cunning things pulsing the battery to determine whether it's fully charged or not.
The '12V' on my car seems to be all over the place 12 to 15.5V it seems! , but as the battery seems to have survived 10 years and 140k miles I leave well alone. To be fair that was measured with a very cheap meter, not a Fluke, trying to find a broken wire in the trailer board or socket.
Jim@sea
Well-Known Member
Bit of advice please before I rush out and buy one of these battery chargers.
My car has a "Stop Start" battery and I mentioned these chargers to an electrician friend who advised me against them for a reason I did not understand.
Are they ok for Stop Start Batteries Please /
My car has a "Stop Start" battery and I mentioned these chargers to an electrician friend who advised me against them for a reason I did not understand.
Are they ok for Stop Start Batteries Please /
lw395
Well-Known Member
Why do you need a battery charger?
Just in case you leave the lights on or something?
Or to float charge when not using the car?
IMHO, these chargers are fine for one-off use, like if you leave the lights on or something but not great for leaving connected long term.
Stop-start batteries are if anything more resistant to overcharging or other abuse. One of these chargers would be OK for occassional use with a stop start car, but if you need to use it for no good reason I suspect you may need a new battery very soon anyway?
If you are not going to be using your car for a month or more, you could do worse than RTFM, as not all cars are identical.
It might be best to disconnect the battery or that might be a world of pain regarding alarms, immobilisers and actually being able to open the boot to reconnect!
Of course the 'Fine' manual may simply say 'have car and wallet towed to main dealer'.
RichardS
N/A
Your stop start battery is probably an AGM and the charger will be fine. I wouldn't keep it permanently connected until we have a better idea of what the float voltage is. However leaving it until the battery symbol stops flashing, or for a week or two after that, if necessary, would be fine.
Richard
