House batteries @ -485

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House batteries @ -485

June 18, 2016, 05:07:02 pm

Picked up the family @ ATL airport with the coach, no issues with security or access. Got home and forgot to plugin, after 2 days noticed the Amp-Hr meter @-485.
Reading other posts it seems that it should not go below -250 with 2 8D units.

Thoughts...??

Thx

Hans

Re: House batteries @ -485

Reply #1 – June 18, 2016, 11:15:25 pm

Hans,

50% (250 amp hrs) down on 2-8Ds is about how far you want to go. -485 is a lot. Especially in two days with nothing on. When the batteries are fully charged it should read about zero and then as you use power it shows power out (-). What brand of battery monitor do you have? It may need to be reset, not sure how to do that without knowing what kind it is.

Re: House batteries @ -485

Reply #2 – June 19, 2016, 06:51:48 am

Roger...This what I have....

CRUISING EQUIPMENT Co.
6315 SEAVIEEW AVE NW.
SEATLE,WA 98107
(206) 782-8100
AMP-HOUR METER INSTALLATION MANUAL 15 April 1992
FUNCTIONS and FEATURES
AMP-HOUR meter counts Amp-hours (Ahrs) used from the battery and displays them
with a minus sign. When charging begins, Ahrs are added until the display reads 0
when the battery is fully charged. Overcharging will continue to add Ahrs and they
will be displayed as a positive number. When discharging begins from the overcharge
state, AMP-HOUR meter automatically resets to 0 and starts counting down as Ahrs
are used.
AMP-HOUR meter automatically compensates for efficiency during charging. The
charge efficiency of every battery is a little different, but if 1Amp-hour is removed from a battery it must be charged with 1.1
to 1.2 Ahrs to replace it. AMP-HOUR meter is factory calibrated with this standard efficiency, but may be field adjusted to your
exact requirements if required.

Re: House batteries @ -485

Reply #3 – June 19, 2016, 07:51:48 am

I looked at the instructions on the web site.
http://www.evdl.org/docs/ce-ah.pdf
If you don't know what the meter read when you started then it is hard to say what is going on. It could have started at zero gone down to -100 back up to -20 then down to -120 then up to -40 and so on.

You need to but the batteries on your charger for a few days until they are at float. At that point the charger should be maintaining them at about 13.4 volts. The meter should read zero. If it does not then you need to disconnect power to the meter and then reconnect it. That should force it to go back to zero.

It does not seem reasonable that you would have used 485 amp hours in 48 hours if there was nothing really on. There are always parasitic loads on the batteries, the amp-hr meter included, but these are pretty small.

So step one is a complete and full recharge. This may actually take more than just a couple days if the batteries are down as far as they may be. See what the meter says. If it is not zero, remove power (red wire in the drawing) and let it set back to zero. It should go to zero or even a positive number when fully charged. When charging is removed it should go back to zero and start counting the amp hrs used as negative numbers.

Let us know what you see.

Re: House batteries @ -485

Reply #4 – June 19, 2016, 11:01:23 am

Amp-Hr currently

+206Hr
13.8 volts
2.0 Amps

Looks like all OK..?

Re: House batteries @ -485

Reply #5 – June 19, 2016, 01:25:14 pm

I wonder if it isn't wired up wrong. The instructions seem to indicate that at full charge it should be close to zero amp hrs. Amp-hrs out + amp hrs in should be about zero. At 13.8 volts you might not quite be to float yet.

So when you think it is fully charged, cut the power to the amp-hr meter and then reconnect it, it should go back to zero.

Look to see where your large negative cable connects to your house batteries. The negative posts should be connected together and then the large negative cable is connected at one end. The shunt should be connected using a short cable to the negative battery post and the large negative cable should be connected to the other end.

Re: House batteries @ -485

Reply #6 – June 19, 2016, 01:36:50 pm

Hans, Roger and I have been discussing your issue offline, trying to figure this out.

If possible post a picture of your house battery ground wiring and shunt hookup, or better yet, your schematic with an arrow where your shunt has been placed. This might shed some light on the readings you're seeing.

Re: House batteries @ -485

Reply #7 – June 19, 2016, 03:05:58 pm

Peter,Roger...just cut power to the coach and turned on inverter.. Monitor went to -0, voltage 13,45, amps -1.7.

photo of batteries. I see one wire from negative terminal (shunt) ??

Re: House batteries @ -485

Reply #8 – June 19, 2016, 03:56:53 pm

Maybe my eyes, but I think I see a lot of cleaning needed on at least the Neg terminal as it looks like corrosion around battery terminal (picture blurry).
Maybe just bad connections??
JohnH

Re: House batteries @ -485

Reply #9 – June 19, 2016, 03:59:00 pm

Quote from: John Haygarth link=msg=236880 date=14 I think I see a lot of cleaning needed on at least the Neg terminal as it looks like corrosion around battery terminal (picture blurry).[/quote

What John said. X-1

Re: House batteries @ -485

Reply #10 – June 19, 2016, 04:03:01 pm

Looks like I'll be busy tomorrow cleaning terminals..

Re: House batteries @ -485

Reply #11 – June 19, 2016, 04:21:12 pm

Hans,

Are you sure that is a house battery? The left heavier + cable looks like it may be the + cable going to the starter...?

Also, you have 2 house batteries, correct, they should be together side by side.

I don't think I see a shunt in these pictures...

Re: House batteries @ -485

Reply #12 – June 19, 2016, 05:00:54 pm

Get a good battery terminal spray cleaner and brush, clean and dry every thing. Be careful to not short anything out. I put a good spray of CorrosionX on the battery posts and the connectors. Clean is good.

Re: House batteries @ -485

Reply #13 – June 19, 2016, 05:04:22 pm

and remove the clamps to do it, negative first. When you put them back on put the neg' last.
JohnH

Re: House batteries @ -485

Reply #14 – June 19, 2016, 05:30:14 pm

Thanks, John, Good reminder. Safety First!

Here are a couple pictures of my battery shunt on the house batteries.

Re: House batteries @ -485

Reply #15 – June 20, 2016, 01:44:10 pm

Cleaning the negative terminals on house batteries today...Have not located the shunt yet ( need to raise coach). FT drawing attached showing Amp-HR Shunt.

Hans

Re: House batteries @ -485

Reply #16 – June 20, 2016, 01:47:54 pm

If the shunt is directly connected to the battery before any other cabled, all of your current readings are suspect.

Re: House batteries @ -485

Reply #17 – June 20, 2016, 02:24:05 pm

Quote from: Hans&Marjet – June 20, 2016, 01:44:10 pm

Cleaning the negative terminals on house batteries today...Have not located the shunt yet ( need to raise coach). FT drawing attached showing Amp-HR Shunt.

Hans

Hans

The shunt in the schematic is in the correct place, measuring any current in or out of the house batteries via the negative cable. Need to verify it is still wired the same, and not accidently changed by a PO or a shop.

Re: House batteries @ -485

Reply #18 – June 20, 2016, 08:00:53 pm

Quote from: prfleming – June 20, 2016, 02:24:05 pm

Hans

The shunt in the schematic is in the correct place, measuring any current in or out of the house batteries via the negative cable. Need to verify it is still wired the same, and not accidently changed by a PO or a shop.

Peter
Raising the coach in the AM and trace the Neg cable to the shunt...

Hans

Re: House batteries @ -485

Reply #19 – June 20, 2016, 08:08:05 pm

Hans

I'm thinking it shouldn't require raising the coach to find it. Should be close to the house batteries mounted on a side panel, or mounted on your main 12V panel near the boost relay, and fuses, etc.

In any case, keep us posted.

Re: House batteries @ -485

Reply #20 – June 20, 2016, 08:39:31 pm

It should be located at or near the battery post, with nothing connected to the post other than the shunt.

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