Kmart battery charger

Submitted: Tuesday, May 09, 2006 at 10:18
ThreadID: 33712 Views:4765 Replies:4 FollowUps:9
This Thread has been Archived
Hi,

Thought I'd test the $99 battery chargers from Kmart discussed on this forum. They are a 15amp and marketed as 3 stage. Tried two and both got up to over 16 volts when the battery was almost fully charged. There is no way to select the voltage, that I could see. Amps was selectable from 2 to 15 but at 16+ volts it's way to high for most batteries bar for an equalisation.
Back Expand Un-Read 0 Moderator

Reply By: TerraFirma - Tuesday, May 09, 2006 at 13:35

Tuesday, May 09, 2006 at 13:35
So no good I take it, what is the optimal voltage for equalisation..? I bought a 10 amp Aussie made unit from SuperCheap , includes Float mode. I didn't measure the volts though.
AnswerID: 171707

Follow Up By: Austravel - Tuesday, May 09, 2006 at 13:50

Tuesday, May 09, 2006 at 13:50
Yep intend taking it back, thought that if it was ok it would be good for the $.

If I were you I'd check the max voltage it may not be like this one but you never know.
0
FollowupID: 427178

Reply By: hl - Tuesday, May 09, 2006 at 14:07

Tuesday, May 09, 2006 at 14:07
Hi,

I would not dismiss the charger out of hand. I depends really how long the 16V stays there and whether it is current limited. Also, your battery may be faulty.
A 3 stage charger does elevate the voltage for the absorb cycle. As long as it doesn't pump 15 amps into the battery at 16V (when it is full) for a few hours I would think it is operating normally.

Cheers
AnswerID: 171710

Follow Up By: Austravel - Tuesday, May 09, 2006 at 14:23

Tuesday, May 09, 2006 at 14:23
Hi,

OK. I thought this might be the case as well. I left it running for about half an hour, it was putting in about 5 amps at 16.2 volts. Battery was ok but to check I ran my good 3 stage charger on it and checked the output, it was around 4+ amps at 14.7 volts when set to lead calcium batteries.

The battery is a sealed lead calcuim so max should be 14.8 volts as per manufacturer's instruction. My concern was that at 16 volts it could cause the plates to distort in the long term and in the short term there would be potential for liquid loss from boiling. I know it's ok to equalize open wet cell batteries up to 16 volts but wasn't sure how well sealed lead/calcium acid batteries would handle it.

Certainly open to your view as for $99 they are a damn cheap unit if they do what they say.
0
FollowupID: 427182

Follow Up By: hl - Tuesday, May 09, 2006 at 14:38

Tuesday, May 09, 2006 at 14:38
Hi again,

Well, I would not be comfortable with a sealed battery to run that sort of current when the battery is already full.
However, you say that it still draws 4 amps at 14.7 with your other charger. It does sound to me like all is not well with that battery. If it were really fully charged and you applied 14.8 Volts to it, it should not draw much at all, I would think well less than 1/2 amp.

Cheers

0
FollowupID: 427189

Follow Up By: Austravel - Wednesday, May 10, 2006 at 08:49

Wednesday, May 10, 2006 at 08:49
Thanks hl,

Could be right about the battery, I put it down to the battery still being quite warm and I only put the better charger on for a few minutes to test the voltage out put so it never went to float, didn't have time. Even so I will recheck the battery. Though the real test for me was to check the max output voltage and I still think it failed. If it had been just over 15 volts and min amps or as you say higher voltage but no current I'd have used it.

On a side note, I know it's been discussed before but can't find a difinitive answer for my particular solar regulator. I have a 20 amp MP3129 charge controller, from ebay/Jaycar. It's rebadged in various names across the world.

Can I buy a cheap 12 volt 20 amp battery charger (no bells and whistles) and run it through the solar regulator which will give me a 3 stage charge?????
0
FollowupID: 427367

Follow Up By: hl - Wednesday, May 10, 2006 at 14:44

Wednesday, May 10, 2006 at 14:44
Hi again,

I also own one of these regulators and I can't see any reason why you couldn't use it as a 3 stage regulator, in fact, it is very configurable for different types of battery.
I don't think I would use it to the max and put a 20 amp supply on it, but any filtered DC supply up to say 15 amps and 17 to 25 volts should do the trick. Beware that chargers generally don't have a filter capacitor and be sure to check the voltage after you add one, with no load. I think the maximum rating of that regulator is 25V in.

Cheers
0
FollowupID: 427460

Reply By: Derek from Affordable Batteries & Radiators - Tuesday, May 09, 2006 at 16:36

Tuesday, May 09, 2006 at 16:36
Hi Aus

Did you speak to one of their qualified staff about the quality and reliability of the charger.

Charging a $300 AGM with a $90 charger sounds like trouble.
AnswerID: 171741

Follow Up By: brett - Tuesday, May 09, 2006 at 21:14

Tuesday, May 09, 2006 at 21:14
"Qualified staff"

Didn't he say he bought it at KMart.

But as someone else said if your quality 3 stage is in float moad at 14.7V and it's still drawing 4 amps then this does not seem right. I'd expect to see under an amp.
0
FollowupID: 427292

Follow Up By: Mad Dog (Australia) - Tuesday, May 09, 2006 at 21:19

Tuesday, May 09, 2006 at 21:19
Could well be better than the cheap rough charger in most automobiles.
0
FollowupID: 427295

Follow Up By: Derek from Affordable Batteries & Radiators - Tuesday, May 09, 2006 at 21:21

Tuesday, May 09, 2006 at 21:21
Yes still too high.

My 3 stage chargers once they 'Float' they will float at a selectable 13.2 / 13.5 / 13.8 Volts and drop down to as low as 40mA.
0
FollowupID: 427297

Follow Up By: Austravel - Wednesday, May 10, 2006 at 13:32

Wednesday, May 10, 2006 at 13:32
Yes Derek I get the plug. Never said I was charging an AGM. Not really any reason that they should cost much more than $100, the technology has been around for some time and has paid for itself. Poor build quality also comes in dear items.

Rather than the sales pitch you could have offered further info for the forum. The idea behind my test was to see if there was a cheaper alternative to the dearer versions for a mate. Thought I'd pass on the info to others. Doubt it will be long before this error is sorted then you'd be hard pressed to justify paying 2-5 times as much for a similar unit just because it has a few extra bells and whistles.
0
FollowupID: 427436

Reply By: Alloy c/t - Wednesday, May 10, 2006 at 15:28

Wednesday, May 10, 2006 at 15:28
Austravel , on a side note you asked if you could use your solar regulator in line as the 3rd stage ,,, If your solar panel regulator is anything like a Steca dont even try any power source other than the solar panel/s ,, been there / done that = 1 fried solar panel regulator.
AnswerID: 171943

Sponsored Links

Popular Products (13)