Power issues

[VanGoOutdoors]

So I have a dec 2016 build camper (so you know the battery age)

Dual exide option, 150ah of power
I have charged the battery to 13.6 v as read on a meter
After 12 hours overnight, with only the fridge set to 5, it's at 12.5v

The math doesn't add up. Everything else is turned off, and from what I can find with the 2ah (two way 85 fridge) the fridge takes, there's no way it should eat up that much voltage.

Thoughts before I spend 500 on two 6 volts?

I am going to pull both batteries and have them tested at camping world, who is an exide dealer, to rule that out, but that seems like far too much of a rapid discharge for the small load.

Thoughts?

 

[nikonron]

Do you have the fridge loaded? It's difficult to cool air. Ron

 

[VanGoOutdoors]

Do you have the fridge loaded? It's difficult to cool air. Ron

There are about 12 bottles of water in there.
but even if it ran continuously (which it doesnt) for 12 hours, thats only in theory 24 amp hours of use from 150, and even if you factor only going to half charger for 75 AH used, the math STILL doesnt add up

 

[Beach]

If you are just turning fridge on and it isn't precooled, then your amp draw is more than 2A. Not to say you don't have a battery issue but you might be drawing 4-5A(or more)/hr X 12hrs, trying to initially cool that fridge

 

[VanGoOutdoors]

The fridge had been on now for 7 days, with no less than 12 bottles of water, never opened for the past two days

 

[Captm]

What type of exide batteries do you have?

 

[nikonron]

13.6 is just a surface charge, do the math from 12.6, which is a more realistic number for a fully charged 12 volt battery. Ron

 

[VanGoOutdoors]

What type of exide batteries do you have?

The deep cycles that come with the four wheel camper.
fp-agm24dp

My big issue, is that im TOLD that the blue sea cutoff is at 12.4v

Well, by this, according to *power charts* its at 75% at 12.4, yet has a low voltage cutoff so the truck battery wont charge it with a theoretical good amount of power.

I have solar, but if overnight the batteries go to 11.9 as they did on my trip, then there is an issue (two fans on medium and fridge)
I may just pull the blue sea isolator and install something lower voltage. I have an X2 power battery in the truck (northstar) that ran my Snomaster fridge for 3 days, didnt hit a low voltage cutoff on the unit, and also charged 3 phones a speaker and two camera batteries all day. Just seems like these batteries arent really giving great performance with that as a benchmark

WHat was pointed out was this item that separates at 12.4v and wont reactivate until 12/4 is reached somehow (solar, generator etc)
https://www.bluesea.com/products/7611/BatteryLink_Automatic_Charging_Relay_-_12V_24V_DC_120A

but i dont read any function of the sort like that on the site.

 

[rando]

This is the problem with using voltage to measure state of charge - the batteries need to be at rest (ie no load, no charge) for at least a couple of hours before making a measurement. If anything I would say the numbers you saw are totally normal. If your fridge was running when you saw 12.6v that would mean your batteries were still almost completely charged. If that was after the fridge had been off for a while then your batteries were at about 75% SOC.

 

[nikonron]

The fans alone will pull 26 amps in 10 hrs. on a medium setting. Ron

 

[PaulT]

So I have a dec 2016 build camper (so you know the battery age)
Dual exide option, 150ah of power
I have charged the battery to 13.6 v as read on a meter
After 12 hours overnight, with only the fridge set to 5, it's at 12.5v
The math doesn't add up. Everything else is turned off, and from what I can find with the 2ah (two way 85 fridge) the fridge takes, there's no way it should eat up that much voltage.
Thoughts before I spend 500 on two 6 volts?
I am going to pull both batteries and have them tested at camping world, who is an exide dealer, to rule that out, but that seems like far too much of a rapid discharge for the small load.
Thoughts?

13.6 volts as charged by IOTA indicates full charge and in float mode. How long after the fridge ran before you checked voltage & found 12.5 volts?

I have seen my voltage with fridge running indicate 12.4v and 20 min after stopping show 12.7 volts. It is normal for the battery to recover some voltage after being under load. That is why the Trimetric is so informative. It is measuring current consumed or added over time rather than guessing by measuring voltage. That gives a truer picture of the state of charge of the battery.

Another issue to confuse things is marketing talk. If a fridge consumes 4 amps while running but runs for a total of 30 minutes per hour in average conditions, it consumes 2 amp hours per hour or an average of 2 amps. So if you know the running current consumption of the fridge and track the actual number of minutes the fridge runs in one hour, you can multiply the running current by total minutes run time in an hour then divide by 60 minutes per hour, you will know how many amp hours your fridge consumed from your batteries.

Do some tests and calculate what is actually happening in your system before assaulting your wallet. You may be better off buying additional solar panels and a Trimetric battery monitor rather than new GC2 batteries. Even with the larger capacity batteries, you just extend the run time before the batteries are depleted if the solar is insufficient to replace the energy consumed per day. Hang in there to better understand your system.
$500 is not an insignificant investment. $400 for a Trimetric & another panel may serve your needs better. In a couple of years, LiFePO4 batteries may be near as cheap as two GC2 batteries and much lighter. Be patient, Grasshopper.
Paul

 

[rando]

The idea behind the Bluesea ACR is that it isolates your camper battery from the truck battery when neither battery is being charged (either voltage goes below 12.75V) and combines then when either battery is being charged ( voltage over 13V). It seems to me that it is also working as designed, but I don't really understand your concern.

The deep cycles that come with the four wheel camper.
fp-agm24dp

My big issue, is that im TOLD that the blue sea cutoff is at 12.4v

Well, by this, according to *power charts* its at 75% at 12.4, yet has a low voltage cutoff so the truck battery wont charge it with a theoretical good amount of power.

I have solar, but if overnight the batteries go to 11.9 as they did on my trip, then there is an issue (two fans on medium and fridge)
I may just pull the blue sea isolator and install something lower voltage. I have an X2 power battery in the truck (northstar) that ran my Snomaster fridge for 3 days, didnt hit a low voltage cutoff on the unit, and also charged 3 phones a speaker and two camera batteries all day. Just seems like these batteries arent really giving great performance with that as a benchmark

WHat was pointed out was this item that separates at 12.4v and wont reactivate until 12/4 is reached somehow (solar, generator etc)
https://www.bluesea.com/products/7611/BatteryLink_Automatic_Charging_Relay_-_12V_24V_DC_120A

but i dont read any function of the sort like that on the site.

 

[MarkBC]

13.6 is just a surface charge, do the math from 12.6, which is a more realistic number for a fully charged 12 volt battery. Ron

This is the problem with using voltage to measure state of charge - the batteries need to be at rest (ie no load, no charge) for at least a couple of hours before making a measurement. If anything I would say the numbers you saw are totally normal. If your fridge was running when you saw 12.6v that would mean your batteries were still almost completely charged. If that was after the fridge had been off for a while then your batteries were at about 75% SOC.

These are it -- a fully charged "12 volt" battery shows about 12.6 to 12.7 volts. So if it's down to 12.5 after running the fridge overnight then I don't think you have a problem..

 

[rando]

I would agree, I think you need to spend some time understanding how your power system works before you start throwing money at it. If you were to spend money on anything, I would start with a BMV-702 .

13.6 volts as charged by IOTA indicates full charge and in float mode. How long after the fridge ran before you checked voltage & found 12.5 volts?

I have seen my voltage with fridge running indicate 12.4v and 20 min after stopping show 12.7 volts. It is normal for the battery to recover some voltage after being under load. That is why the Trimetric is so informative. It is measuring current consumed or added over time rather than guessing by measuring voltage. That gives a truer picture of the state of charge of the battery.

Another issue to confuse things is marketing talk. If a fridge consumes 4 amps while running but runs for a total of 30 minutes per hour in average conditions, it consumes 2 amp hours per hour or an average of 2 amps. So if you know the running current consumption of the fridge and track the actual number of minutes the fridge runs in one hour, you can multiply the running current by total minutes run time in an hour then divide by 60 minutes per hour, you will know how many amp hours your fridge consumed from your batteries.

Do some tests and calculate what is actually happening in your system before assaulting your wallet. You may be better off buying additional solar panels and a Trimetric battery monitor rather than new GC2 batteries. Even with the larger capacity batteries, you just extend the run time before the batteries are depleted if the solar is insufficient to replace the energy consumed per day. Hang in there to better understand your system.
$500 is not an insignificant investment. $400 for a Trimetric & another panel may serve your needs better. In a couple of years, LiFePO4 batteries may be near as cheap as two GC2 batteries and much lighter. Be patient, Grasshopper.
Paul

 

[VanGoOutdoors]

The fans alone will pull 26 amps in 10 hrs. on a medium setting. Ron

Which in combination with the fridge, should only halfway kill ONE battery in theory?

Do some tests and calculate what is actually happening in your system before assaulting your wallet. You may be better off buying additional solar panels and a Trimetric battery monitor rather than new GC2 batteries. Even with the larger capacity batteries, you just extend the run time before the batteries are depleted if the solar is insufficient to replace the energy consumed per day. Hang in there to better understand your system.
$500 is not an insignificant investment. $400 for a Trimetric & another panel may serve your needs better. In a couple of years, LiFePO4 batteries may be near as cheap as two GC2 batteries and much lighter. Be patient, Grasshopper.
Paul

I have an analyzer in the mail actually to hook up and monitor everything. I literally just got this thing and am trying to figure it out as it "SEEMS" terribly inefficient compared to my teardrop

The idea behind the Bluesea ACR is that it isolates your camper battery from the truck battery when neither battery is being charged (either voltage goes below 12.75V) and combines then when either battery is being charged ( voltage over 13V). It seems to me that it is also working as designed, but I don't really understand your concern.

I was told that if it goes under 12.4 that it would not couple back together and receive charge from the truck battery. That i would have to bring the camper batteries up to above that in order to recouple.

 

[Squatch]

1st I don't think that your fridge is only drawing 2 amps. Most use the same compressor these days.

My efficient TF51 draws 2.5 amps when running in economy mod and draws 4.5+ on Max mode.

It can run a good bit if it's hot out or not fully loaded.

Yesterday was fairly cool for this time of year. Where parked my main solar panel is shaded. So I've been leaving my aux panel hooked up. About 1pm yesterday I had 100% charge and disconnected the Aux panel. There has been little sun at all on the main panel since. At about 10am I checked and I was down to 88% of my 110ah deep cycle per my Trimetric. Pretty normal draw with just the fridge.

I can't speak to other monitors as I haven't used them. But I love the data I get from my Trimetric + RV2030 combo. Simple, effective, accurate. I'd be running blind in the dark without it.

At any given time it shows exactly what draws or charging is going on.

 

[rando]

I was told that if it goes under 12.4 that it would not couple back together and receive charge from the truck battery. That i would have to bring the camper batteries up to above that in order to recouple.

That is incorrect. Read the spec sheet, it will only keep the batteries isolated if either is below 9.5V (ie dead as doornail). Otherwise, if EITHER battery goes over 13V it will combine them.

 

[VanGoOutdoors]

Thatorrect. Read the spec sheet, it will only keep the batteries isolated if either is below 9.5V (ie dead as doornail). Otherwise, if EITHER battery goes over 13V it will combine them.

That's what it appeared to me from the documents.

So really, i just need to put 250 watts on the roof, and have a great day is what yall are telling me.
Good to to. Thanks for the education guys!

 

[Squatch]

I have 1) 160 watt panel on the roof and 1) 110 ah battery. I don't run an inverter or laptops ect off the camper. Just lights, furnace, and fridge.

I don't even have wiring hooked up to my truck as I haven't needed it. Unless the sun doesn't shine for several days I'm good. I have an additional 120watt folding panel I made that can be added and moved around if needed. it mainly gets used in the driveway when the camper is parked under the trees. In comfortable weather I can normally go 3-5 days with little to no charging. This is fridge on full time, furnace for a couple of cycles before bed and in the am, using and led light I installed. The furnace in my camper draws 2.5 amps for the fan and gas solenoid when running.

 

[VanGoOutdoors]

I have 1) 160 watt panel on the roof and 1) 110 ah battery. I don't run an inverter or laptops ect off the camper. Just lights, furnace, and fridge.

I don't even have wiring hooked up to my truck as I haven't needed it. Unless the sun doesn't shine for several days I'm good. I have an additional 120watt folding panel I made that can be added and moved around if needed. it mainly gets used in the driveway when the camper is parked under the trees. In comfortable weather I can normally go 3-5 days with little to no charging. This is fridge on full time, furnace for a couple of cycles before bed and in the am, using and led light I installed. The furnace in my camper draws 2.5 amps for the fan and gas solenoid when running.

I think the fans just may be the huge power suck. its 90-100 during the day, and 80s at night, so gotta run em for the wifey. Not a huge deal. Ill put a power monitor in and go from there. Like I said, its more coming from my efficient teardrop with 110AH running for 4 days without needing solar, to this with many more systems, just an adjustment.