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Author Topic: 12 v smart charger  (Read 468 times)
farmer joe
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« on: March 12, 2019, 01:17:20 PM »

I am looking for a smart 12 v battery charger (5 amps + ) that I can operate off a timer that will not need resetting every time it gets switched off and on.
If any one has any ideas thanks
Joe
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biff
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« Reply #1 on: March 12, 2019, 02:33:33 PM »

  I had a couple of those.
     Built in the UK. Small 150mm x 500mm x 200mm long. Intelligent charger with 3 little green light and an on off switch. They cost 28 each and are 12 amp. I blew one up but the other is still going strong. I saw a similar design a few years ago. You can switch them on and off at the plug without having to go near the charger itself. Mine charges a pair of 100 amp x 12v Yousa SLAS.  Argus also sold them one time. Mine are 10 years +. When the wind dies down I will post a pic of the remaining one and also a 24v charger in a UPS that charges and operates the same way .Quite rare.
           Biff
« Last Edit: March 12, 2019, 02:38:36 PM by biff » Logged

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Scruff
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« Reply #2 on: March 12, 2019, 03:41:00 PM »

No such thing. If you want a 12v mediocre charger ctek are good by the extremely low benchmark.
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biff
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« Reply #3 on: March 12, 2019, 03:54:01 PM »

Well, OK Scruff,
      When this wind dies down, Biff will head out and take a pic or two and post them. Then we can decide if it is good or bad or indifferent. Anything that gives me good service for 10 years+ cannot be bad.
                 Biff
   
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Scruff
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« Reply #4 on: March 12, 2019, 04:42:45 PM »

Does it bring your cells to specific gravity 1.275?
That is after all what a charger is supposed to do.

The first "Edison" light bulbs lasted decades...you could see them but not much else.  wackoteapot
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Westie
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« Reply #5 on: March 12, 2019, 04:51:42 PM »

It is really annoying that these (no so) smart chargers go into standby after a power cut.  I have a Ctek 5A unit and that also goes to standby. I also have the original Oxford oximiser which immediately resumes maintenance charge on restoration of the power but the new Oximiser 3 also powers on in standby facepalm.

It seems to me that they now support so many charging modes that they need you to decide which one is applicable.  
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Scruff
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« Reply #6 on: March 12, 2019, 06:42:46 PM »

Any Ctek (mostly MXS range) I have used is "automatic".
Meaning that any power cycling results in a new charge cycle without human intervention.
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marcus
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« Reply #7 on: March 12, 2019, 07:19:04 PM »

I used to have a ctek that would work as soon as the supply was connected - trouble was it would become a (small) drain on the battery if the mains was off so you needed to isolate it from the battery (i.e. operate a switch) anyway if you wanted to avoid that - though you could automate that with a relay if you wanted to.

Quote
Does it bring your cells to specific gravity 1.275?
That is after all what a charger is supposed to do.

That's not a job for a smart charger - you want a traction battery charger. Most folk who buy smart chargers are looking to more-or-less recharge a low maintenance car/leisure/gel battery without worrying about overcharging and boiling off the electrolyte - so that's what they do - and they will fully equalise at float voltage if they're floated for long enough. If you want one to fully equalise a battery ASAP then it's a traction battery charger + a tub of deionised water (or hydro-caps). Right tool for the right job.
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Scruff
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« Reply #8 on: March 12, 2019, 07:45:39 PM »

trouble was it would become a (small) drain on the battery if the mains was off so you needed to isolate it from the battery (i.e. operate a switch) anyway if you wanted to avoid that - though you could automate that with a relay if you wanted to.

Back current drain, it'll be listed on the datasheet.
Usually eff all onna big ship.


That's not a job for a smart charger

 Shocked

That is the job of every charger, charge the battery, avoid sulphation... Roll Eyes

without worrying about overcharging and boiling off the electrolyte

Wouldn't be an issue if they designed it right. MorningStar seem to manage this just fine.

they will fully equalise at float voltage if they're floated for long enough.
Have you evidence to support this?

I have a Victron stoopid charger...it claims to be smart though.  wackoold
It never, ever, in a year of Sundays charges better than 1.26

If you want one to fully equalise a battery ASAP then it's a traction battery charger + a tub of deionised water (or hydro-caps). Right tool for the right job.


proper EQ takes days to weeks and very low current on a new/healthy battery.
If you are inserting tubs of de-ionised on any charger (single cycle) you are doing it wrong or don't care because downtime on the forklift costs more money than it's worth.
« Last Edit: March 12, 2019, 07:57:13 PM by Scruff » Logged
Westie
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« Reply #9 on: March 12, 2019, 09:42:25 PM »

Any Ctek (mostly MXS range) I have used is "automatic".
Meaning that any power cycling results in a new charge cycle without human intervention.

Mines an xc800, quite old - not one of their best, as you say the MXS range does resume to last mode selected on return of power.
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marcus
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« Reply #10 on: March 12, 2019, 09:48:06 PM »

trouble was it would become a (small) drain on the battery if the mains was off so you needed to isolate it from the battery (i.e. operate a switch) anyway if you wanted to avoid that - though you could automate that with a relay if you wanted to.

Back current drain, it'll be listed on the datasheet.
Usually eff all onna big ship.
Well in that particular instance it was 50mA on a 80Ah battery - so I preferred to isolate it. Point is though, the OP wanted to know it there were any out there that would come on without being 'switched on' and I remember ctek used to make them so...

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That's not a job for a smart charger

 Shocked

That is the job of every charger, charge the battery, avoid sulphation... Roll Eyes
Well... yes and no. I make my own charge controllers so don't know much about morningstar/vitron, etc, but a 'smart' charger can't actually measure the SG of each cell so it has to guess by charge amps. I'm guessing that your morningstar can be programmed to switch to float at a current appropriate to the battery it's connected to? whereas a generic smart charger from halfords can't - so expecting it to properly equalise whatever battery you happen to connect to it before switching to float would be unreasonable.

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without worrying about overcharging and boiling off the electrolyte

Wouldn't be an issue if they designed it right. MorningStar seem to manage this just fine.
well like I said - don't know much about them or how they do it - but I do know they're not cheap.

Quote
they will fully equalise at float voltage if they're floated for long enough.
Have you evidence to support this?
sort of:-
my battery is an AGM i bought 2nd hand back in '05? can't remember TBH. originally running a solar off grid system and following the manufacturers recommended charging voltage: 13.56v per 12v - no equalisation voltage recommended. Obviously being AGM it's a little difficult to measure SG so I can only judge equalisation by charge current @ float. I came to the empirical opinion to judge them equalised when the charge current fell below 0.0001C ( 10mA per 100Ah) as they didn't seem to go appreciably lower.
in mid summer I found that they would equalise over 3 or 4 days on solar power alone (lightly discharged overnight). during the winter months I'd switch to a grid powered charger once a month overnight to equalise(i.e. charging on solar during the day, then grid until next day - so about 36ish hrs @ float). all without exceeding 13.56v (well - the temperature compensated equivalent voltage anyway). Battery is still going today - they have an easy life now as I've had hydro for 11months/year for the last 3 years on average. Haven't done a formal capacity test, but they were fine during this summers drought and have held up fine through a few winter hydro-outages.

Another example is the pig electric fence battery:  an old car battery I inherited that can't crank an engine anymore but still has a rest voltage of 12.7v. it has a 32w solar panel and a 13.8v shunt regulator. I bring it back once a year at christmas for an overnight on the old-fashoned car battery charger as the pigs are down in the valley bottom and there are a lot of trees to shade the winter sun off the panel. been there for 3 yrs now and the last time the pigs were 'away' and I checked the rest voltage of the battery:- still 12.7v - so it must manage 11months of equalisation at 13.8v.


Quote
If you want one to fully equalise a battery ASAP then it's a traction battery charger + a tub of deionised water (or hydro-caps). Right tool for the right job.


proper EQ takes days to weeks and very low current on a new/healthy battery.
weeks? - not my experience - and my batteries seem to be lasting OK - see above. very low current? well, yes - see above.

Quote
If you are inserting tubs of de-ionised on any charger (single cycle) you are doing it wrong or don't care because downtime on the forklift costs more money than it's worth.
well this is outside my personal experience TBH but I understand from folks using forklifts every day they do take a lot of water - that's just the price of having them ready for the next morning.
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Scruff
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« Reply #11 on: March 12, 2019, 10:20:15 PM »

MorningStar from observation are logging the discharge cycle and returning charge appropriately to discharge behavior.
1 day cycle 10% DOD = 105% charged
3 week cycle 55% DOD = 125% charged.
I find the controllers are a lot cheaper than replacing batteries, very reliable and hold their resale value.
I buy them used, use them until I find a better one and then sell them for more than I paid in the first place...QED they're better than free... Grin

Everyone else uses an hourglass and a sextant twould seem.

Saying conservative charging is best is like saying the manufacturer decided to slowly damage the battery because the user won't maintain it instead of giving the user the option to damage it themselves (not watering) or maintaining it..
If it ain't fit for porpoise, it ain't fit for porpoise...I do not care why!

I'm very tired of batteries being blamed for poor longevity when it's inevitably the charger or user.
How do we fix this? Spend 5 times the price on a different chemistry of new fangled lightweight battery with a whole new set of problems like spontaneous combustion.

If yer battery held 12.7V and wouldn't turn a starter motor, I reckon the battery was either too small outtov the gates or the starter was on the way out.
Equalising a battery is easy. Equalising to SG 1.28 takes time, persistence and low current.

Ctek MXS 5 back-current drain is 1.3mA
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marcus
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« Reply #12 on: March 13, 2019, 12:24:11 AM »

Ah well if morningstar are doing all that then they will do well; not sure why victron don't as they're supposed to be 'quailty' (they're certainly expensive last time I checked).
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Everyone else uses an hourglass and a sextant twould seem.
Aye - well as long as my batteries last (which they seem to) I'll keep on doing my own thing  Smiley

Quote
I'm very tired of batteries being blamed for poor longevity when it's inevitably the charger or user.
me too - usually the user IME - just last month I checked a (smart) charger for someone who's electric fence battery was only lasting a few months - charger worked as it's designed to so I asked (again) if they were re-charging early enough - like when the battery drops below say, 12.5v, 12.4? certainly before it gets down to 12.0 (as I'd explained to them on at least two occasions before?
 "oh well the fence energiser shuts off automatically" they say
"and what voltage is that?" I ask
" I don't know" they say

10.5v  banghead

Quote
If yer battery held 12.7V and wouldn't turn a starter motor, I reckon the battery was either too small outtov the gates or the starter was on the way out.
You're right - it came with a tractor and it was patently too small for that engine (not enough CCA) and a cheapo battery to boot - I think some of the plates have cracked/broken so it can't get close to even it's rated CCA no more - still good AH for a light load like a fencer though.

the ctek came with a camper van I had quite a few years back (and went away with it) - may've been faulty - but I rarely'  nedeed it so I just isolated it as the simple solution
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Scruff
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« Reply #13 on: March 13, 2019, 03:26:36 AM »

not sure why victron don't as they're supposed to be 'quailty' (they're certainly expensive last time I checked).

They certainly have a higher failure rate than the rest of their competitors if you keep an eye on the used ebay market.
I think they must spend all the money on marketing instead of R&D.

Aye, was it the pricetag inspired such brand confidence?...they ride that line well. Expensive enough to command respect, yet cheaper than the rest of that league.
Worst of the best I call 'em.

Never met a product of theirs without some glaringly obvious flaws any half decent engineer would have to address.

Now available with bluetooth (but still can't do the simple task you bought it for... Roll Eyesbanghead
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