|
12-30-2019, 08:18 AM
|
#1
|
Senior Member
Join Date: Nov 2017
Location: Tampa FL
Posts: 502
|
SOC dropped from 99 to 94, does that seem excessive
I just had a Magnum Battery monitor added to my coach and I'm wondering if the loss I'm receiving in two days is excessive or not.
In two days I've gone from a SOC of 99 to 94, that seems like a lot to me for just two days. I had the battery disconnect switch on, so the only draw I'm aware of is the inverter and the battery monitor system itself. I show a -.02 amp draw which doesn't seem like much.
I'm assuming this is normal amp loss for the inverter and the battery monitor.
My question is, does it seem unusual to go from a SOC of 99 to 94 in two days?
__________________
2018 Coachmen Sportscoach 408DB
41 foot DP
2018 Jeep Wrangler JL -Alpha Blue Ox and RVI3
It's never too late to do the right thing!
|
|
|
|
Join the #1 RV Forum Today - It's Totally Free!
iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!
You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!
|
12-30-2019, 09:03 AM
|
#2
|
Senior Member
Join Date: Jul 2018
Posts: 3,165
|
I have to ask cause I don't have a playbook. What does SOC stand for?
__________________
2011 Keystone Sprinter 323 BHS. Port Charlotte Fl/Hinsdale MA. Retired Master Electrician. All Motor homes are RV's. All RV's are not Motor homes.
|
|
|
12-30-2019, 09:06 AM
|
#3
|
Moderator Emeritus
Join Date: Jan 2000
Location: West Palm Beach, FL. USA
Posts: 27,563
|
State Of Charge (battery charge level).
__________________
Gary Brinck
Former owner of 2004 American Tradition and several other RVs
Home is West Palm Beach, FL
|
|
|
12-30-2019, 09:08 AM
|
#4
|
Senior Member
Monaco Owners Club
Join Date: Jun 2014
Posts: 14,498
|
The SOC (state of charge) draw you have is normal, there are other parasitic draws that drop the battery voltage.
__________________
Jim J
2002 Monaco Windsor 38 PKD Cummins ISC 350 8.3L
2005 Jeep Grand Cherokee w/5.7 Hemi
|
|
|
12-30-2019, 09:20 AM
|
#5
|
Moderator Emeritus
Join Date: Jan 2000
Location: West Palm Beach, FL. USA
Posts: 27,563
|
Well, an inverter wastes power when just idling, so best to turn it off if you are trying to minimize battery loss. But your 0.02A reading suggests it is Off, so maybe your draw is just the safety equipment (e.g. LP detector, CO detector). Another possibility is that the inverter has a smart sense circuit and is cycling on/off, so causing a higher draw at times yu are not seeing.
You are using 0.02 amps (20 milli-amps) which actually sounds quite low for parasitic load on a nicely equipped motorhome. That's only 0.48 Amp-hrs/day, but we can't say how that affects the SOC without knowing the battery amp-hour capacity you have dialed into the monitor. It calculates SOC based on what you tell it vs actual amps. 1 amp-hour is a 1% drop in SOC if you have a 100 AH battery bank, but it's only 0.25% drop if its a 400 AH battery bank.
Still, it seems the change in SOC is probably more than the 0.02 amp rate suggests. A 5% drop in a 400 AH battery bank is more than a 0.02 amp draw, so maybe you have other laods that come and go and you aren't observing the amp rate from them.
__________________
Gary Brinck
Former owner of 2004 American Tradition and several other RVs
Home is West Palm Beach, FL
|
|
|
12-30-2019, 09:49 AM
|
#6
|
Senior Member
Join Date: Nov 2017
Location: Tampa FL
Posts: 502
|
Gary, my battery bank is 434 amp hours and it's configured for 430 amp hours. The inverter is off, but the battery monitor itself is on as well as the remote panel inside the coach that I'm getting the SOC and amp discharge reading from.
__________________
2018 Coachmen Sportscoach 408DB
41 foot DP
2018 Jeep Wrangler JL -Alpha Blue Ox and RVI3
It's never too late to do the right thing!
|
|
|
12-30-2019, 10:22 AM
|
#7
|
Senior Member
Join Date: Jul 2018
Posts: 3,165
|
Quote:
Originally Posted by Gary RVRoamer
State Of Charge (battery charge level).
|
That was my guess but I had to ask to be sure.
__________________
2011 Keystone Sprinter 323 BHS. Port Charlotte Fl/Hinsdale MA. Retired Master Electrician. All Motor homes are RV's. All RV's are not Motor homes.
|
|
|
12-30-2019, 11:16 AM
|
#8
|
Senior Member
Join Date: Nov 2017
Location: Tampa FL
Posts: 502
|
Gary, do you know the best way to make sure that the negative lead at the inverter is connected to the shunt? They are on opposite sides of my coach so I can't use a multimeter and the cables are not labeled.
Quote:
Originally Posted by Gary RVRoamer
Well, an inverter wastes power when just idling, so best to turn it off if you are trying to minimize battery loss. But your 0.02A reading suggests it is Off, so maybe your draw is just the safety equipment (e.g. LP detector, CO detector). Another possibility is that the inverter has a smart sense circuit and is cycling on/off, so causing a higher draw at times yu are not seeing.
You are using 0.02 amps (20 milli-amps) which actually sounds quite low for parasitic load on a nicely equipped motorhome. That's only 0.48 Amp-hrs/day, but we can't say how that affects the SOC without knowing the battery amp-hour capacity you have dialed into the monitor. It calculates SOC based on what you tell it vs actual amps. 1 amp-hour is a 1% drop in SOC if you have a 100 AH battery bank, but it's only 0.25% drop if its a 400 AH battery bank.
Still, it seems the change in SOC is probably more than the 0.02 amp rate suggests. A 5% drop in a 400 AH battery bank is more than a 0.02 amp draw, so maybe you have other laods that come and go and you aren't observing the amp rate from them.
|
__________________
2018 Coachmen Sportscoach 408DB
41 foot DP
2018 Jeep Wrangler JL -Alpha Blue Ox and RVI3
It's never too late to do the right thing!
|
|
|
12-31-2019, 05:48 AM
|
#9
|
Senior Member
Join Date: May 2004
Location: MI
Posts: 2,155
|
To measure total system draw there should be a single ground cable to the battery (bank) and the shunt should be in that.
If you want to measure continuity to a component your leads won't reach you can use a piece of wire from the meter lead to the point you want to test.
|
|
|
12-31-2019, 12:20 PM
|
#10
|
Moderator Emeritus
Join Date: Jan 2000
Location: West Palm Beach, FL. USA
Posts: 27,563
|
It doesn't matter of the inverter negative goes to chassis ground instead of direct to the shunt or battery. You just have to make sure the shunt is between the battery and chassis ground and that nothing is bypassing that.
If you are reading the SOC from the inverter panel, then it is suspect. You want the SOC from the shunt monitor panel.
__________________
Gary Brinck
Former owner of 2004 American Tradition and several other RVs
Home is West Palm Beach, FL
|
|
|
|
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
|
|
Thread Tools |
Search this Thread |
|
|
Display Modes |
Linear Mode
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
» Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
|