BMV 702 exclamation mark on display

[MtB]

Two or three years ago I installed a BMV 702 ammeter which works fine. However shortly after installing it one of the preset alarms sounded, which I reset by correcting the condition it was warning about. Cn't remember what it was.

 

However, ever since then there has been a little exclamation mark in the display which reading the manual, tells me an alarm has been triggered. Well yes I know this!

 

What I can't find in the manual is how to get rid of the exclamation mark. Does anyone here know how please? I'm sure it must be in the manual somewhere but I just can't see it for looking!

[WotEver]

1 hour ago, Mike the Boilerman said:

What I can't find in the manual is how to get rid of the exclamation mark. Does anyone here know how please? I'm sure it must be in the manual somewhere but I just can't see it for looking!

I would imagine that’s what menu item 63 “Clear History” is for, no?

[MtB]

On 01/07/2018 at 23:16, WotEver said:

I would imagine that’s what menu item 63 “Clear History” is for, no?

 

Thanks for your suggestion. I've just tried clearing the history and the bluddy exclamation mark persists. 

 

This is annoying me beyond all reason!!

[WotEver]

2 minutes ago, Mike the Boilerman said:

 

Thanks for your suggestion. I've just tried clearing the history and the bluddy exclamation mark persists. 

 

This is annoying me beyond all reason!!

You need some tippex

[MtB]

4 minutes ago, WotEver said:

You need some tippex

 

Good idea! 

 

Or just stop peering at the BMV every ten minutes....

 

But I'm conducting the 'battery capacity' test to confirm my suspicion my Yuasas have finally responded to an hour of brutal solar equalising every day for thew last year.

 

It's not looking good though. 16ah (at 24v) drawn since I disconnected the solar panels yesterday at 7pm and SG now says 87%.

Edited July 3, 2018 by Mike the Boilerman

[WotEver]

Just now, Mike the Boilerman said:

 

Good idea! 

 

Or just stop peering at the BMV every ten minutes....

 

But I'm conducting the 'battery capacity' test to confirm my suspicion my Yuasas have finally responded to an hour of brutal solar equalising every day for thew last year.

Gibbo once commented to me that “the last bit of sulphation can be a right bugger to remove and require hours and hours of pretty high voltages” so hopefully that’s exactly what you’ve done

 

[Robbo]

On 01/07/2018 at 22:10, Mike the Boilerman said:

Two or three years ago I installed a BMV 702 ammeter which works fine. However shortly after installing it one of the preset alarms sounded, which I reset by correcting the condition it was warning about. Cn't remember what it was.

 

However, ever since then there has been a little exclamation mark in the display which reading the manual, tells me an alarm has been triggered. Well yes I know this!

 

What I can't find in the manual is how to get rid of the exclamation mark. Does anyone here know how please? I'm sure it must be in the manual somewhere but I just can't see it for looking!

It does say in the manual “An alarm is acknowledged when a button is pressed.  However, the alarm icon is displayed as long as the alarm condition remains.”

 

My guess is that the condition still remains, so check your settings (including the relay settings).

Edited July 3, 2018 by Robbo

[MtB]

2 minutes ago, WotEver said:

Gibbo once commented to me that “the last bit of sulphation can be a right bugger to remove and require hours and hours of pretty high voltages” so hopefully that’s exactly what you’ve done

 

 

Something else I'm wondering. Despite the batteries fizzing enthusiastically for an hour every day for a year, when I checked the electrolyte in three rndon cells the other day and got those three perfect readings, the level in the cells was still above the plates and I don't think I've ever topped them up with distilled water. Certainly haven't in the past year.

 

Do you think this suggests the electrolyte was over-diluted when I got them new? What effect on batteries does over-diluted electrolyte have? 

3 minutes ago, Robbo said:

It does say in the manual “An alarm is acknowledged when a button is pressed.  However, the alarm icon is displayed as long as the alarm condition remains.”

 

My guess is that the condition still remains, so check your settings.

 

Hmmmm thanks. I wonder if I have inadvertently set a stoopid alarm alarm parameter that never gets satisfied. I don't think so but will check. There are quite a lot to look through.

 

 I remember the alarm sounding but can't remember what it was. I think I discharged the batts down to about 20% once. Can't check either now though as I've cleared the history!

[WotEver]

16 minutes ago, Mike the Boilerman said:

Can't check either now though as I've cleared the history!

Sorry...

 

17 minutes ago, Mike the Boilerman said:

What effect on batteries does over-diluted electrolyte have? 

Lowered capacity. 

[MtB]

7 minutes ago, WotEver said:

Lowered capacity. 

 

A lot lower? I wonder if my capacity has come back then simply from boiling off the excess H2O. 

 

The SGs were never as high as they should have been IIRC even when apparently fully charged.

[nicknorman]

31 minutes ago, Mike the Boilerman said:

 

Something else I'm wondering. Despite the batteries fizzing enthusiastically for an hour every day for a year, when I checked the electrolyte in three rndon cells the other day and got those three perfect readings, the level in the cells was still above the plates and I don't think I've ever topped them up with distilled water. Certainly haven't in the past year.

 

Do you think this suggests the electrolyte was over-diluted when I got them new? What effect on batteries does over-diluted electrolyte have? 

 

If they are Trojanoids then one would expect them to behave as such. With our leisure use and having them on a low float voltage of 13.25 when not on the boat, I find I need to top up our "proper" ones a few times a year. If you have never topped them up I suggest you are not charging them enough! Again, if like the real thing, there is quite a large volume of electrolyte above the plates. Certainly a noticeable difference in sg between plates just covered, and electrolyte at the specified full level. I think it is unlikely they were filled with weak acid, more likely there is still sulphation and your "good" sgs were only thus because a lot of water was missing.

 

By the way, the electrolyte level varies according to SoC. So if the level is only a little above the plates when fully charged, there is a risk of the tops of the plates being exposed when the batteries are discharged.

Edited July 3, 2018 by nicknorman

[MtB]

Ok I've done the 'capacity test' From 100% SoC on completion of a cycle of solar equalising down to 50% indicated on the Smartgauge, the discharge according to the BMV702 was 62AH. 

 

So my battery bank although seeming better than last year, is still only 124AH, against a badge capacity of 225AH

 

Still haven't figured out how to dispose of the exclamation mark though!

[WotEver]

15 minutes ago, Mike the Boilerman said:

Ok I've done the 'capacity test' From 100% SoC on completion of a cycle of solar equalising down to 50% indicated on the Smartgauge, the discharge according to the BMV702 was 62AH. 

 

So my battery bank although seeming better than last year, is still only 124AH, against a badge capacity of 225AH

 

Still haven't figured out how to dispose of the exclamation mark though!

Shame. 

 

I presume you discharged them reasonably gently?

[MtB]

1 hour ago, WotEver said:

Shame. 

 

I presume you discharged them reasonably gently?

 

Yes. Took two days, which also confirmed my consumption is still in the order of 30ah per day at 24v.

[BruceinSanity]

2 hours ago, Mike the Boilerman said:

Still haven't figured out how to dispose of the exclamation mark though!

What happens if you disconnect the BMV altogether and leave it powered down overnight?

[MtB]

35 minutes ago, BruceinSanity said:

What happens if you disconnect the BMV altogether and leave it powered down overnight?

 

Dunno!

 

I see from the manual I can do a factory reset on it. So I'll try that then I'll KNOW there are no weird alarms inadvertently set up. And that ought to clear the exclamation mark too.