Battery charger problems

I hope someone can give me some input here.

I've got a projecta battery charger, Projecta MC121150 - Batteries Plus Technologies , in my van.

We left the 12volt fridge on last time we used it and screwed the batteries, now replaced with 2 new agm but the charger wont charge them, the red light comes on saying power but it wont go to charge or float, although if i pull the batteries and charger out and charge them on the ground it charges fine.

I hooked all the wiring back up the same way it came off so I know thats okay, I have no idea what else could be causing, so before I ring an auto leccy I was hoping someone here may have an idea.

Cheers in advance
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Reply By: david m5 - Sunday, Apr 29, 2012 at 20:43

Sunday, Apr 29, 2012 at 20:43
I have a Projecta 10 amp charger and don't think it is a quality product . Wouldn't buy another one. sorry cant tell you why its not charging.
AnswerID: 484569

Reply By: The Bantam - Sunday, Apr 29, 2012 at 23:32

Sunday, Apr 29, 2012 at 23:32
Most of these funky multistage chargers work best when there is a direct relationship with one battery.

I have heard reports that some can be confused by other loads in the system and even other wiring.

There have also been cases wher multistage chargers have done a spac and got confused and overcharged batteries.

While I like multistage chargers and there are some realy good ones arround I can see a very good case for simple old fashon 13.8 volt analogue power supplies to float cahrge batteries long term.

It worked reliably for decades in many emergency power supplies.

AnswerID: 484581

Reply By: Nomadic Navara - Monday, Apr 30, 2012 at 01:49

Monday, Apr 30, 2012 at 01:49
Put the batteries and charger back. Disconnect all loads and check the charging. That should work like when you have them on the ground. When you have things charging normally, reconnect your loads one at a time and see what happens each time.

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AnswerID: 484588

Reply By: Nutta - Monday, Apr 30, 2012 at 06:56

Monday, Apr 30, 2012 at 06:56
Thanks for some constructive answers, I will try that NN, good idea, cheers, Wayne.
AnswerID: 484593

Reply By: Member - John and Val - Monday, Apr 30, 2012 at 07:57

Monday, Apr 30, 2012 at 07:57

If it all works when set up outside the van then the charger is ok. Either your reinstalling in the van didn't go quite right, or there is something in the van that's causing trouble. I'd check your installation first - are the positive battery terminals connected together? ditto the negative terminals. Is the charger positive connected to the battery positives? ditto negatives.

If your installation checks out, as Peter suggests, I'd disconnect all loads and if that fixes it, add them back one by one until the charger won't start. This should isolate the trouble maker. My gut feel is that the fridge may be providing a heavy load that in company with the batteries is upsetting the charger.


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AnswerID: 484597

Reply By: lesterb - Monday, Apr 30, 2012 at 13:56

Monday, Apr 30, 2012 at 13:56
Are you sure the original batteries were screwed? Did you try connecting them to the charger without any load? I suspect that having the fridge connected across flat batteries is the problem. My fridge has a label inside that says it draws 12.5A on 12v DC. When connected and on that would only allow another 2.5A from a 15A charger for the batteries. Maybe it is the charger output overload protection kicking in.
AnswerID: 484629

Reply By: Nutta - Monday, Apr 30, 2012 at 20:12

Monday, Apr 30, 2012 at 20:12
Thanks for the help guys, i'm not so sure the batteries were stuffed, i may have jumped the gun, never the less they are long gone and now i have the agms in.

I did have them connected separately outside of the van separately but not together and each one charged, so tomorrow i am going to take them out and connect them together on the charger, at least i can start working out if its the both together that is upsetting things, if it charges then i will try putting one wire on at a time as nomadic navara suggested.

I will read up on the overload thing and see if that may be it.

Cheers again.
AnswerID: 484663

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