How Low A Battery Level Is Too Low? - Escape Trailer Owners Community
Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×

Go Back   Escape Trailer Owners Community > Escape Tech > Escape Systems | Water, Waste, Charging & Propane
Click Here to Login
Reply
 
Thread Tools Display Modes
 
Old 01-10-2017, 07:21 PM   #1
Senior Member
 
nathanj04011's Avatar
 
Join Date: Jul 2015
Location: Midcoast, Maine
Trailer: 2016 Escape 5.0 TA
Posts: 435
How Low A Battery Level Is Too Low?

So just call me a noob. That's ok, I have not problem with that. When it comes to anything electrical (ok, you got me...when it comes to ANYTHING) I'm not too bright.

Here's the back story: We have the solar option and 2 6V batteries. We also are keeping our trailer in our driveway, and so far this year the temperatures have been all over the place. I opted to keep the batteries in the trailer with the an extension cord handy to plug in should the solar not keep the batteries charged. I also have the the battery toggle switch in the trailer turned off.

So due to snow covering the solar panel, and due to the fact that I just haven't checked up on the trailer in about a month (where is the devotion?!!), when I took a peek at it just now, the solar panel indicator shows an 88% charge. I intend on plugging in it to charge it up, but before I do, I'd like to get an understanding.

Does anyone know what the lowest percentage, according to the solar panel monitor, is the lowest you should go before you run the risk of ruining your battery? I have seen the voltage chart many times, both on this forum and others, but I kinda like the percentage view, as its an easy way of understanding things. At least for me.

Also, the user manual for the GoPower (I think?) makes it seem as though each battery is connected separately to A and B on the panel, but on ours, it looks like there is nothing on B, so this confuses me even more than I am accustomed to (Kinda like when I have to tie my shoes instead of wearing slip ons). Is this a customary thing, to have both batteries attached to A?

None of these things have been problematic so far, but its winter and I have nothing else to contemplate. Thank you everyone in advance for your help!
nathanj04011 is offline   Reply With Quote
Old 01-10-2017, 07:24 PM   #2
Site Team
 
rbryan4's Avatar
 
Join Date: Jun 2014
Location: Canyon Lake, Texas
Trailer: 2015 19 "Past Tents", 2021 F150 Lariat 2.7L EB
Posts: 10,222
The way the batteries are wired, think of them as one high capacity 12 volt battery. As for the amount of discharge before damaging something, they are deep cycle batteries, which are designed for a good amount of discharge before recharging. Having said that, a good rule of thumb is to not allow them to discharge below 50% repeatedly. That will shorten their life span.
__________________
"You can't buy happiness, but you can buy an RV. And that is pretty close."
rbryan4 is offline   Reply With Quote
Old 01-10-2017, 07:30 PM   #3
Senior Member
 
nathanj04011's Avatar
 
Join Date: Jul 2015
Location: Midcoast, Maine
Trailer: 2016 Escape 5.0 TA
Posts: 435
Quote:
Originally Posted by rbryan4 View Post
The way the batteries are wired, think of them as one high capacity 12 volt battery. As for the amount of discharge before damaging something, they are deep cycle batteries, which are designed for a good amount of discharge before recharging. Having said that, a good rule of thumb is to not allow them to discharge below 50% repeatedly. That will shorten their life span.
Thanks Robert! How does that work though? They say a 12V batteriy shouldn't go below 11.53V, yet that's not actually 50% of the 12V...told you I wasn't bright!!
nathanj04011 is offline   Reply With Quote
Old 01-10-2017, 07:55 PM   #4
Site Team
 
rbryan4's Avatar
 
Join Date: Jun 2014
Location: Canyon Lake, Texas
Trailer: 2015 19 "Past Tents", 2021 F150 Lariat 2.7L EB
Posts: 10,222
Putting voltage output aside, more important is amp hours and the c-rate. That's the rate at which a battery discharges, in relation to its maximum amp hour capacity. The dual 6V batteries on an escape are rated at a maximum capacity of 232 amp hours. So, 50% discharged would mean you have only 116 amp hours remaining. There are tons of complicated formulas for calculating discharge rate, etc, but to keep it simple, if your panel says you have 88% of your capacity remaining, it's relatively close to that. Some have installed a better battery monitor, like a Trimetric, which is more accurate than the GoPower.
__________________
"You can't buy happiness, but you can buy an RV. And that is pretty close."
rbryan4 is offline   Reply With Quote
Old 01-10-2017, 07:57 PM   #5
Senior Member
 
nathanj04011's Avatar
 
Join Date: Jul 2015
Location: Midcoast, Maine
Trailer: 2016 Escape 5.0 TA
Posts: 435
Quote:
Originally Posted by rbryan4 View Post
Putting voltage output aside, let's look at amp hours and the c-rate. That's the rate at which a battery discharges, in relation to its maximum amp hour capacity. The dual 6V batteries on an escape are rated at a maximum capacity of 232 amp hours. So, 50% discharged would mean you have only 116 amp hours remaining. There are tons of complicated formulas for calculating discharge rate, etc, but to keep it simple, if your panel says you have 88% of your capacity remaining, it's relatively close.
Thanks again! Good to know, and I'll make sure it stays over 50%.
nathanj04011 is offline   Reply With Quote
Old 01-10-2017, 07:59 PM   #6
Site Team
 
rbryan4's Avatar
 
Join Date: Jun 2014
Location: Canyon Lake, Texas
Trailer: 2015 19 "Past Tents", 2021 F150 Lariat 2.7L EB
Posts: 10,222
By the way, when my trailer is in storage it often goes below 75% on the monitor if it's been sitting there under cover for an extended period. The batteries recover nicely to 100% within a few hours of the panel being exposed to sunlight. Often they recover within the time it takes to tow the trailer from the storage yard to my house.
__________________
"You can't buy happiness, but you can buy an RV. And that is pretty close."
rbryan4 is offline   Reply With Quote
Old 01-10-2017, 09:09 PM   #7
Senior Member
 
alanmalk's Avatar
 
Join Date: Apr 2014
Location: Arvada, Colorado
Trailer: 2015 E'21 - 'Velocity'. Tow: Toyota Tacoma V6, 4X4, manual.
Posts: 1,684
Quote:
Originally Posted by nathanj04011 View Post
Thanks Robert! How does that work though? They say a 12V batteriy shouldn't go below 11.53V, yet that's not actually 50% of the 12V...told you I wasn't bright!!
The care and feeding of batteries can be very complicated or very simple, and it depends on your need and desire to know all the gory details.

If you want the simple answer, to avoid ulcers and tearing of hair (if you are lucky enough to have hair), then pick your favorite number - say, 75%, and plug in and charge if it drops below that. Or as an alternative, pick a voltage, say 12.4v and charge if it drops below.

With the main toggle switch in the off position (which is easy to verify by attempting to turn on one of the trailer lights) the main discharge will be from internal losses in the batteries - and there is nothing you can do about that. But as others have pointed out, that lost charge is easy to replace.

Do confirm that on a sunny day that the charge % goes up significantly. This to confirm that the solar system is working.

To be honest I haven't looked at my charge % since September.

Now, if you are on the other end of the "need to know" spectrum then read up about using a hydrometer to measure charge. And read sales materials on battery amp-hour monitors. You can develop a new hobby revolving around batteries...

--
Alan
alanmalk is offline   Reply With Quote
Old 01-10-2017, 09:31 PM   #8
Site Team
 
rbryan4's Avatar
 
Join Date: Jun 2014
Location: Canyon Lake, Texas
Trailer: 2015 19 "Past Tents", 2021 F150 Lariat 2.7L EB
Posts: 10,222
Quote:
Originally Posted by alanmalk View Post
You can develop a new hobby revolving around batteries...

--
Alan
You got that right Alan. The furthest I'll probably go is a better charger and a better monitor.
__________________
"You can't buy happiness, but you can buy an RV. And that is pretty close."
rbryan4 is offline   Reply With Quote
Old 01-10-2017, 09:45 PM   #9
Senior Member
 
thoer's Avatar
 
Join Date: Oct 2009
Location: Galesville, Wisconsin
Trailer: 2017 21 "Blue II" & 2017 Highlander XLE (previously 2010 17B "Blue" & 2008 Tacoma)
Posts: 4,232
Quote:
Originally Posted by rbryan4 View Post
You got that right Alan. The furthest I'll probably go is a better charger and a better monitor.
I can quit anytime...
__________________
Eric (and Mary who is in no way responsible for anything stupid I post)

"Beware of false knowledge; it is more dangerous than ignorance." George Bernard Shaw
thoer is offline   Reply With Quote
Old 01-10-2017, 10:13 PM   #10
Senior Member
 
alanmalk's Avatar
 
Join Date: Apr 2014
Location: Arvada, Colorado
Trailer: 2015 E'21 - 'Velocity'. Tow: Toyota Tacoma V6, 4X4, manual.
Posts: 1,684
Quote:
Originally Posted by thoer View Post
I can quit anytime...
Wish I could. I built a computer controlled battery charger that uses "ideal diodes" and a "lossless regulator". It could monitor each of my 12v batteries and isolate the weakest one for a fast (bulk) charge or put them in parallel when discharging. But I scrapped the whole thing after learning that my AGM batteries had virtually no self-discharge or circulating losses when connected in parallel. And I also realized that the 15% extra charge from using a lossless regulator wasn't worth the effort.


I need professional help...
--
Alan
alanmalk is offline   Reply With Quote
Old 01-11-2017, 07:49 AM   #11
Senior Member
 
Join Date: Sep 2009
Location: Southwick, Massachusetts
Trailer: None, sold my 2014 5.0TA
Posts: 7,124
I've read on battery manufacturer web sites that to prevent freezing keep them at 100%. If your going down to 88% in a month and you won't be using the trailer I'd pull one of the battery leads. I'm surprised you loose that much with the 12vdc switch have off.
__________________
Happy Motoring
Bob
padlin is offline   Reply With Quote
Old 01-11-2017, 08:22 AM   #12
Senior Member
 
nathanj04011's Avatar
 
Join Date: Jul 2015
Location: Midcoast, Maine
Trailer: 2016 Escape 5.0 TA
Posts: 435
Quote:
Originally Posted by padlin View Post
I've read on battery manufacturer web sites that to prevent freezing keep them at 100%. If your going down to 88% in a month and you won't be using the trailer I'd pull one of the battery leads. I'm surprised you loose that much with the 12vdc switch have off.
Well, it did get into the single digits the past few nights. I have no idea if that reduces the level or not. It is sunny today and will be in the low 50's and due to rain we got last night, all the snow melted off the solar panel, so I am going to check the level tonight when I get home. We have had strange weather here in Maine this winter!

I kept the leads hooked up so that a charge could be supplied to the batteries, either by the solar panel or an extension cord, if needed. If I pulled a lead, I wouldn't readily know what the levels are, unless I got a tester of some sort. I may not do this next year, but I thought that using the indicator would be a reasonably decent way of keeping an eye on where the levels should be. As I have found out rather often, what do I know?
nathanj04011 is offline   Reply With Quote
Old 01-11-2017, 09:14 AM   #13
Site Team
 
rbryan4's Avatar
 
Join Date: Jun 2014
Location: Canyon Lake, Texas
Trailer: 2015 19 "Past Tents", 2021 F150 Lariat 2.7L EB
Posts: 10,222
Quote:
Originally Posted by padlin View Post
I've read on battery manufacturer web sites that to prevent freezing keep them at 100%. If your going down to 88% in a month and you won't be using the trailer I'd pull one of the battery leads. I'm surprised you loose that much with the 12vdc switch have off.
I was kind of surprised by that too Bob when I saw it. Thing is, it went right back to 100% in the 8 mile trip from the storage to my house. Not sure how accurate the GoPower monitor was. I have a really nice battery tester and it showed all cells in great shape.
__________________
"You can't buy happiness, but you can buy an RV. And that is pretty close."
rbryan4 is offline   Reply With Quote
Old 01-11-2017, 11:05 AM   #14
Senior Member
 
Jill's Avatar
 
Join Date: May 2014
Location: Sacramento area, California
Trailer: 2015 Escape 21
Posts: 524
Quote:
Originally Posted by alanmalk View Post
If you want the simple answer, to avoid ulcers and tearing of hair (if you are lucky enough to have hair), then pick your favorite number - say, 75%, and plug in and charge if it drops below that. Or as an alternative, pick a voltage, say 12.4v and charge if it drops below.
When you say the 12.4v, is that on the solar monitor? Or is that a separate battery monitor? I'm beginning to think I need a separate battery monitor other than the one that Escape provides that shows 1/3, 2/3 or full. If so, does anyone have recommendations for what I should get if I don't want anything too complicated?
Jill is offline   Reply With Quote
Old 01-11-2017, 11:17 AM   #15
Senior Member
 
thoer's Avatar
 
Join Date: Oct 2009
Location: Galesville, Wisconsin
Trailer: 2017 21 "Blue II" & 2017 Highlander XLE (previously 2010 17B "Blue" & 2008 Tacoma)
Posts: 4,232
Jill, there are lot of inexpensive one like this available. This one is kinda nice as it also has USB charging outlets. I have a different one so can't speak for the quality of this one:
https://www.amazon.com/Charger-Melon...arge+indicator

I have this one and it has proved reliable and accurate when tested with multimeters :
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
__________________
Eric (and Mary who is in no way responsible for anything stupid I post)

"Beware of false knowledge; it is more dangerous than ignorance." George Bernard Shaw
thoer is offline   Reply With Quote
Old 01-11-2017, 11:20 AM   #16
Senior Member
 
Jill's Avatar
 
Join Date: May 2014
Location: Sacramento area, California
Trailer: 2015 Escape 21
Posts: 524
Quote:
Originally Posted by thoer View Post
Jill, there are lot of inexpensive one like this available. This one is kinda nice as it also has USB charging outlets. I have a different one so can't speak for the quality of this one:
https://www.amazon.com/Charger-Melon...arge+indicator

I have this one and it has proved reliable and accurate when tested with multimeters :
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
Well that's pretty cool - and all I have to do is plug it in. I envisioned something that would have to be hooked up directly to the batteries. Thanks!!
Jill is offline   Reply With Quote
Old 01-11-2017, 11:45 AM   #17
Senior Member
 
Vermilye's Avatar
 
Join Date: Feb 2010
Location: Oswego, New York
Trailer: 2017 Escape 21C, 2018 Ford F150
Posts: 5,363
Quote:
Originally Posted by thoer View Post
Jill, there are lot of inexpensive one like this available. This one is kinda nice as it also has USB charging outlets. I have a different one so can't speak for the quality of this one:
https://www.amazon.com/Charger-Melon...arge+indicator
There is a limited amount of battery information the typical solar controller can measure. Battery voltage is about it. The per cent readout on the GoPower controller is not all that accurate, since all it does is attempt to interpret the battery voltage. I've often found it reading 100% while the batteries were charging either via the solar panels or the converter when I knew the batteries were 30 or more amp hours discharged. I'd never use the per cent reading when the batteries are charging.

Under the right conditions a voltage measurement gives an acceptable reading of your battery state of charge. The best is to do a specific gravity measurement, but most don't since it can be messy, you are playing with battery acid & you need a hydrometer, the tool used to make the measurement.

To get an accurate voltage measurement, it must be with all charging sources off (if you have solar, that means at night unless you have added a switch to disconnect the panels). A small 1 - 2 amp load should be placed on the batteries to remove what is called surface charge or let the batteries sit with no load (or charging) for at least 6 hours. If you use the small load to remove the surface charge, disconnect it after an hour or so, then, again with no load or charging, measure the voltage. There is a good chart on the first linked Trojan site or additional information & chart at Mark Nemeth's "12V Side of Life, Parts 1 & 2" that compares voltage to charge per cent. As others have stated, to get the maximum life from your batteries, don't let them go below 50%.

While either checking the specific gravity or the preparation for an accurate voltage measurement a bit of trouble to go through, it is best way to determine the true state of your battery charge level.

By the way, the three links in this post are excellent sources of information on using & maintaining batteries.
__________________
Jon Vermilye My Travel Blog
Travel and Photo Web Page ... My Collection of RV Blogs 2018 F150 3.5EB, 2017 21
Vermilye is offline   Reply With Quote
Old 01-11-2017, 12:06 PM   #18
Senior Member
 
alanmalk's Avatar
 
Join Date: Apr 2014
Location: Arvada, Colorado
Trailer: 2015 E'21 - 'Velocity'. Tow: Toyota Tacoma V6, 4X4, manual.
Posts: 1,684
Quote:
Originally Posted by Jill View Post
When you say the 12.4v, is that on the solar monitor? Or is that a separate battery monitor? I'm beginning to think I need a separate battery monitor other than the one that Escape provides that shows 1/3, 2/3 or full. If so, does anyone have recommendations for what I should get if I don't want anything too complicated?
The solar monitor (aka solar charge controller) reads both voltage and percentage.
Voltage and Percent have essentially the same meaning, just use different numbers.
The numbers come directly from the battery and are very useful.

You can buy a hand held volt meter which is handy for debugging many electrical
problems, but I have no reason to think the solar monitor is not equally accurate.

The battery monitor that reads in a similar fashion as the holding tanks is not
particulary useful - in that "1/3, 2/3, full", is not close enough to be meaningfull.
By time a battery reads 1/3 you are in the damage zone and will shorten the lifespan
of the battery if you repeat 1/3 day after day. For maximum lifespan of the battery
you want to recharge at the magic 50% level, if not earlier.

--
Alan
alanmalk is offline   Reply With Quote
Old 01-11-2017, 12:11 PM   #19
Senior Member
 
alanmalk's Avatar
 
Join Date: Apr 2014
Location: Arvada, Colorado
Trailer: 2015 E'21 - 'Velocity'. Tow: Toyota Tacoma V6, 4X4, manual.
Posts: 1,684
Quote:
Originally Posted by Vermilye View Post
...
I'd never use the per cent reading when the batteries are charging.
...
Good advice. The best measurements are taken when the battery is "resting".
In real life, when camping, try to take a reading first thing in the morning
before the sun starts serious charging. Assuming of course that nothing was
on during the night using (much) 12v.

--
Alan
alanmalk is offline   Reply With Quote
Old 01-11-2017, 12:31 PM   #20
Senior Member
 
thoer's Avatar
 
Join Date: Oct 2009
Location: Galesville, Wisconsin
Trailer: 2017 21 "Blue II" & 2017 Highlander XLE (previously 2010 17B "Blue" & 2008 Tacoma)
Posts: 4,232
Ok, Jill, I'm hesitant to wade in here as Jon and Alan both know a lot more than I do about solar and batteries. But anyway, here is a chart that might help - however even it is open to dispute, but it does give you some ballpark numbers if you want them. It has served my needs well enough over the years. As Jon and Alan said, it is only useful when the "surface charge" is dissipated from the batteries. I just wait a couple hours after charging to test mine....
Attached Thumbnails
batterylevels.jpg  
__________________
Eric (and Mary who is in no way responsible for anything stupid I post)

"Beware of false knowledge; it is more dangerous than ignorance." George Bernard Shaw
thoer is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




» Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by Escape Trailer Industries or any of its affiliates. This is an independent, unofficial site.


All times are GMT -5. The time now is 11:39 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright 2023 Social Knowledge, LLC All Rights Reserved.