Cristec charger fault

[crazyH]

Back in October I bit the bullet and forked out for a shorepower charger to keep the batteries topped up over winter.

I set it to 13.4volts (recommended for my batteries) and all seemed well.

A couple of months ago I was doing some wiring stuff and noticed that the voltage on the batteries was only 12.6V (no loads on batteries and batteries charged); following some more tests over the next 24 hrs I noted that the voltage output of the charger was not constant , but varied between 13.8 and 12.6 (this was probably the battery's normal not-on-charge voltage).

As it's still in warranty I've been in contact with the manufacturer and they asked me to do some more measurements (with batteries and loads disconnected, etc) and I sent them the results.

In a nutshell I adjusted the trimmer to get the voltage back to 13.4v and monitored the voltage over the next few days (no loads) - it varied, but reached an all time low of 11.8v. I sent this info back to the manufacturer expecting them to say something like "send it in for repair it's obviously not working properly" but instead I got a reply saying:-

[ QUOTE ]
Looking at the measurements you did, we think that your charger is working fine.
On an exceptional basis, We are agree to make a free of charge expertise of your charger but you will have to afford the carriage from UK to France and then from France to UK (except if we find a fault).


[/ QUOTE ] /forums/images/graemlins/mad.gif

As far as I can see, a charger set to 13.4v and putting out 11.8 is NOT working fine. but If I pay to post it back to Cristec and they then claim it's still working fine I'm even more out of pocket.

Can anyone advise on how I should proceed with this (trading standards? statutory rights?). I've sent them an e-mail asking them to explain how it can be working 'fine' when it's outputting 11.8v, but not yet had a reply.

A
PS for info: I tried 3 voltmeters just to be sure - 2 digital and one analogue - all more-or less agree.

 

[davidwf]

If you bought it in the UK then under the sale of goods act its up to the retailer to sort it out for you. I'd take it back to the retailer.

 

[VicMallows]

My initial feeling is that you have a dud cell in the battery. This occaisonally occures in quite new and otherwise "good" batteries. If your charger is a 2 (or more) stage charger, it would pump an initial high charge into the battery and get the voltage up to the point where it cut back to a trickle charge. The charge would then be insufficient to maintain a voltage on the dud cell.

Just an idea that may be completely wrong in your case. Of course if the battery has exposed inter-cell connections or you can check the SG, this is easy to verify and you may well have already done so?

What's the battery voltage after it's been resting for a few days?

Vic

 

[crazyH]

Thanks for your replies,

Vic: sorry, perhaps I didn't make it clear: The 11.8 volts is the voltage output of the charger with the battery disconnected; connecting the battery raises the voltage to 12.6v (the battery is about 12.5-ish volts after resting for a few days) i.e. the battery voltage.

david: I initially went back to the retailer but he just passed it on to Cristec. I guess I can try him again.

for info: yes it is a 3 stage charger but I've switched the 'boost' stage off so it should output a fixed 13.4v (the reason for this is that the charger doesn't distinguish between current drawn by the battery and current drawn by a load - so if I turn on enough loads to exceed it's threshold- about 3.7 amps - it goes back into boost mode even though the batteries are charged).

A

 

[VicMallows]

Have to agree with you then that it looks like an intermittent fault in the charger.

David is quite correct that your redress is with the supplying dealer, and it is up to him, not you, to argue the case with Cristec.

Having said that, they do appear to be a substancial well organised outfit so surprised if they're giving you a hassle. It's nice to see detailed technical info on their site (in good English!).

Good Luck, Vic

 

[Guest]

Just a few quick questions:

When it is at its low voltage state and you disconnect then reconnect the mains what happens?
Do this with the battery disconnected but not with the boost enabled. Try is also with the battery connected.

I am thinking along the lines of the charger has shut down due to a fault condition. Overheating, input voltage problem, control panel disconnected etc. Does it have an error light on the unit?

Are you using it with a single output or multiple banks?

 

[crazyH]

disconnecting and reconnecting doesn't restore the voltage to normal. Having said that, if the charger is left off for a few days it does seem to come back on around 14.1v (boost option OFF) but then drops over 1/2 hour to something around the right value. But then over the next several hours it usually falls again to a lower value.

There are no fault indications. During my tests there has been no loading except the (charged) batteries which will draw a few amps initially but fall quickly.

I though along similar lines (that the charger might be shutting down and I was seeing residual voltage), so when the charger was showing 11.8V (battery disconnected) I put a load across the output to see if it was outputting anything - it was - it lit a 25watt nav light lamp and still showed 11.8v on the meter. It is still 'on' - just appears to be putting out the wrong voltage.

cheers for your input - I think my next option is to discuss with the dealer, but if he still supports Cristec I guess I have to pay the postage?

A

 

[crazyH]

Oh, forgot your last question: I'm using it with 3 batteries - if the charger is working I see 13.4v on both main outputs and ~13.0 on third output (this it what's supposed to happen - third o/p is for engine start battery).

When voltage drops the batteries just assume ther 'rest' voltages as the charger output drops (bat 1 12.5ish, bat 2 12.8ish and start bat 12.3 ish from memory).

Cristec only recommended disconnecting 1 battery (bat 1) and I didn't want to run the charger open circiut without their clearance, so battery disconnected values are measured across bat 1 output with the other outputs still connected to their batteries. When output on Bat 1 was 11.8v the other outputs were the normal battery 'rest' voltages.

A

 

[Guest]

Sorry, I have no idea. Most battery chargers should work without the battery (since the wide spread use of battery switches on boats) If it can, then the last test would be to run it without batteries and see how stable the voltage is over time. It is only alternators that should not be disconnected abruptly due to the high destructive voltages generated.