Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: RetiredGuns on January 23, 2019, 12:34:53 pm
Title: Auto Low Voltage Shutoff Modification
Post by: RetiredGuns on January 23, 2019, 12:34:53 pm
So, I was wondering if anyone has ever Installed a Device either Off - the - Shelf, or Home Made, DIY Sensing Circuit to Automatically Shut Down the entire DC Circuit, in any condition that the House Batteries go below a Critical Set Point? This of course would certainly extend the life of our Expensive House Batteries! A Manual Override could be the Courtesy "Salesman" Switch by the front door, to reset them, and to know to charge the system ASAP! I have been pondering such a Device/System, especially since I shelled out nearly $2K for new Batteries. Seems to me it would be a Worthwhile endeavor? Any Thoughts on this perhaps? I do not want to re-invent the wheel here, if someone has tackled this endeavor?
I do realize the Inverters already do this with the AC Circuit, but see the need in the DC System, as well. Nothing worse than Killing the Batteries, or at the very least not keeping them happy and where they like to be! I also realize that Solar Panels assist, in that too, but an actual Shut-Down of the Batteries, automatically is yet another Safe Guard.
Title: Re: Auto Low Voltage Shutoff Modification
Post by: Travelin' Man (RIP) on January 23, 2019, 12:47:20 pm
How about genset auto start when DCV drop to 12.2?
Title: Re: Auto Low Voltage Shutoff Modification
Post by: Protech Racing on January 23, 2019, 12:55:36 pm
Pretty sure that my PSW inverter has that . Never have run them under 12.4, so it is set under that .
Title: Re: Auto Low Voltage Shutoff Modification
Post by: RetiredGuns on January 23, 2019, 01:14:32 pm
How about genset auto start when DCV drop to 12.2?
That, of course is a Popular Option, which I now do not have, but would just like it to Shut the DC off, instead, because of different scenarios, such as being gone for weeks sometimes, and also do keep the Coach, at one location while out and about, for several days, doing explorations without it! That Genny isn't the quietest, as we all know! I Installed a 3rd 8D Battery, in the System, and do have a Marine Selector switch so it acts like a Backup when Boondocking, etc. It's normal mode is to be tied into the other two batteries Most of the time, but manually turn it off, to be a Backup. Not the Best Practice, I realize, but again, having an Auto Shutdown would make that Not Neccasary?
Title: Re: Auto Low Voltage Shutoff Modification
Post by: Travelin' Man (RIP) on January 23, 2019, 02:32:05 pm
For what you want to do you don't need automatic. You need a master switch that kills all parasitic draw when you leave, and when you come back charge the batteries if needed.
Title: Re: Auto Low Voltage Shutoff Modification
Post by: Protech Racing on January 23, 2019, 04:09:22 pm
12 Volt 100 Amp Low Voltage Battery Disconnect Battery Saver Battery... (https://www.ebay.com/itm/12-Volt-100-Amp-Low-Voltage-Battery-Disconnect-Battery-Saver-Battery-Protector/112994047911?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649)
Title: Re: Auto Low Voltage Shutoff Modification
Post by: craneman on January 23, 2019, 07:50:49 pm
10.5 volts might be too late to protect the batteries.
Title: Re: Auto Low Voltage Shutoff Modification
Post by: its toby on January 23, 2019, 08:54:18 pm
I installed a few automatic low voltage disconnects in trucks for the bunks. They work well and on a truck with only one battery bank they paid for themselves in a hurry. Straightforward installation well worth having.
Title: Re: Auto Low Voltage Shutoff Modification
Post by: RetiredGuns on January 24, 2019, 01:34:54 am
For what you want to do you don't need automatic. You need a master switch that kills all parasitic draw when you leave, and when you come back charge the batteries if needed.
I'd prefer an Automatic system, I'm lucky to remember my own name, these days! LOL
I installed a few automatic low voltage disconnects in trucks for the bunks. They work well and on a truck with only one battery bank they paid for themselves in a hurry. Straightforward installation well worth having.
Do you happen to have a Link to those? Thanks!
Title: Re: Auto Low Voltage Shutoff Modification
Post by: RetiredGuns on January 24, 2019, 01:50:41 am
10.5 volts might be too late to protect the batteries.
I agree, the 12.2vDC Low End, is what I would strive for! But if this Module could be Modified, I might use this as a Device to tinker with, unless it already exists, out there, perhaps? The sensing Circuit Schematic would clue me to what I need to tweek!
Title: Re: Auto Low Voltage Shutoff Modification
Post by: RetiredGuns on January 24, 2019, 01:54:55 am
BTW, this is the Battery I went with Good price point, and so far, good Service! I Installed 3 of them, now with only 2 as the OEM Install. The jury is out though, as I only have a little over a Month of usage since I installed them! https://www.wholesalebatteriesdirect.com/vision-heavy-duty-sealed-agm-solar-batteries/79050-12-volt-330ah-8d-ev8d-330a-at-sealed-agm-heavy-duty-solar-battery.html
Title: Re: Auto Low Voltage Shutoff Modification
Post by: Jack Lewis on January 24, 2019, 07:07:47 am
Tom and Barb, I would expect them to work fine as by the case they look like they are made by East Penn. I now have similar East Penn (Dominater. Oreilys Auto) batteries I bought used last year, they were new in 2013 and I've used them for over a year. A member was kind to sell me them for what would have been his core charge. I would question their cycle count as their listing comes no where near where East Penn is publishing. The following pdf data from East Penn you may find as useful and is another clue to cycles. Page 10 of the East Penn pdf shows 370 cycles at 50%, 925 @ 75% for AGM as typical.
I am still researching my next battery selection and have not made a final selection yet. I am leaning towards the following GEL 8Ds as I can pick them up in Roseburg, Oregon. 8G8D | MK Battery 12v 225 AH Deep Cycle Gel 8G8D Battery (https://www.batterystuff.com/batteries/mk-battery-12v-225-ah-deep-cycle-gel-cell-battery-with-automotive-terminal-posts-8g8d.html)
.
Title: Re: Auto Low Voltage Shutoff Modification
Post by: wolfe10 on January 24, 2019, 08:50:24 am
There IS a "got ya" with low voltage settings for cutouts.
Totally agree that you do not want to go below 12.2 VDC for long battery life. BUT (large BUT) that is voltage with batteries AT REST.
If you have on a heavy load, particularly an inverter-drawn load, voltage can easily drop into the high 11's under load and bounce back into the lower 12's when returned to rest.
May be quite frustrating to have a battery with a SOC (State Of Charge) of 65% and still have the low voltage device cut off power.
Title: Re: Auto Low Voltage Shutoff Modification
Post by: bbeane on January 24, 2019, 10:24:26 am
I don't know about 370 cycles @ 50%. My east Penn AGMs are 4 years old. We boondock most of the time running on solar so they get workout. They are still performing as new. The generator has only 75 hours in the last 12 mos. on cloudy days the generator auto start comes on at 12.20 volts.
Title: Re: Auto Low Voltage Shutoff Modification
Post by: jor on January 24, 2019, 10:45:11 am
Quote
May be quite frustrating to have a battery with a SOC (State Of Charge) of 65% and still have the low voltage device cut off power.
That's my experience. When I first started messing around with auto-start I set it too high and the generator would start when not necessary. I don't have any solar though. jor
Title: Re: Auto Low Voltage Shutoff Modification
Post by: craneman on January 24, 2019, 10:55:30 am
My Xantrex SW3012 lets me set how long the low voltage event can take place before shutting down. It also is capable of starting a generator using the same parameters, but I haven't figured out how to set that part up using a do not start during certain hours. In the morning using the microwave or coffee maker won't shut the inverter off. As Brett said the voltage comes back up after their use.
Title: Re: Auto Low Voltage Shutoff Modification
Post by: RetiredGuns on January 24, 2019, 01:25:46 pm
Tom and Barb, I would expect them to work fine as by the case they look like they are made by East Penn. I now have similar East Penn (Dominater. Oreilys Auto) batteries I bought used last year, they were new in 2013 and I've used them for over a year. A member was kind to sell me them for what would have been his core charge. I would question their cycle count as their listing comes no where near where East Penn is publishing. The following pdf data from East Penn you may find as useful and is another clue to cycles. Page 10 of the East Penn pdf shows 370 cycles at 50%, 925 @ 75% for AGM as typical.
I am still researching my next battery selection and have not made a final selection yet. I am leaning towards the following GEL 8Ds as I can pick them up in Roseburg, Oregon. 8G8D | MK Battery 12v 225 AH Deep Cycle Gel 8G8D Battery (https://www.batterystuff.com/batteries/mk-battery-12v-225-ah-deep-cycle-gel-cell-battery-with-automotive-terminal-posts-8g8d.html)
.
In my what I considered Exhaustive research, I came back to the Battery I now have! It is actually a Chinese Battery and they sell worldwide, and are THE Largest Battery Supplier in that realm, from what I gather? Outselling any other manufacturer. That doesn't make them the Best, of course, but says something, anyway? They have not gained much traction here in the USA, as yet, as East Penn has the Market mostly in the USA! They have their largest Facility and Headquarters, only like 40 miles from me, and I considered getting Blems. They said it is rare they have Blem availability in 8D size though, because of the enormous amount of Lead in them, they just recycle it! I also found out they have not used Virgin Lead in like 50 years, as well, because of recycling! Only time will tell, if I get good service from these, but Look at Battery Prices these days!
I do believe I got more bang for my buck! As has been said here, many times, Weight is the deciding factor in the Better Battery! This one has won that category, hands down! I am not endorsing them, at all, but glad to be the Guinea Pig and give feedback, as to what I experience with them! I want to Pamper them, as much as I can, and see by replies I might be going in the WRONG (?) Direction of expecting them not to ever go below 12.2 vDC, to maintain them? I just have to find a reasonable Set Point, I guess, and find a way to achieve that goal? All a Huge Learning curve for me, but I have never bought a Battery that went bad before it's time, either! We shall see????
Title: Re: Auto Low Voltage Shutoff Modification
Post by: Protech Racing on January 25, 2019, 02:10:41 pm
http://vi.raptor.ebaydesc.com/ws/eBayISAPI.dll?ViewItemDescV4&item=112994047911&category=48618&pm=1&ds=0&t=1531362417000&ver=0 The included pic says 11.0 volts, Under load. This might be 12.2+- at rest. My guess is that if it needed to be higher to function properly, it would be . Ihad one and sent it back when my PSW inverter contained the same protection .
1000W 2000 Watt Power Inverter Pure Sine Wave 12V dc 110V 120V ac LCD Remote... (https://www.ebay.com/itm/1000W-2000-Watt-Power-Inverter-Pure-Sine-Wave-12V-dc-110V-120V-ac-LCD-Remote-RV/232635463941?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649) I have not encountered the low voltage cutout. The lowest Ihave seen is 12.3 . I fire gen set at 12.4 .
Title: Re: Auto Low Voltage Shutoff Modification
Post by: Tim on January 26, 2019, 01:05:00 pm
I designed an automatic backup circuit, where the engine battery will automatically supply the house with power.
PROS: - Simple diodes have high reliability - Automatic, instantaneous backup (<1 microsecond) - No noise, no generator, no mechanical switches or relays required - Keeps all house systems running. E.g. Fridge, heaters
CONS - If the house batteries are not recharged within a few days, the engine battery could be discharged - Not off-the-shelf. Self-warranty and support. - Boost circuit removed. Only engine battery is used to start coach.
I removed the Boost and diode battery isolator circuits from my rig since the lithium batteries are charged with solar power. This eliminated the need for the existing antequated, fault-prone designs.
See the following schematic.
Title: Re: Auto Low Voltage Shutoff Modification
Post by: RetiredGuns on January 26, 2019, 09:25:09 pm
I designed an automatic backup circuit, where the engine battery will automatically supply the house with power.
PROS: - Simple diodes have high reliability - Automatic, instantaneous backup (<1 microsecond) - No noise, no generator, no mechanical switches or relays required - Keeps all house systems running. E.g. Fridge, heaters
CONS - If the house batteries are not recharged within a few days, the engine battery could be discharged - Not off-the-shelf. Self-warranty and support. - Boost circuit removed. Only engine battery is used to start coach.
I removed the Boost and diode battery isolator circuits from my rig since the lithium batteries are charged with solar power. This eliminated the need for the existing antequated, fault-prone designs.
See the following schematic.
Understood! I like that! You even have P/N's too! Thanks! Did you source from Mouser Electronics? I will be in the neighborhood of Fry's Electronics in a week or so, too! That is just what I was looking for! BTW, According to my Manual, the Vehicles Starting Batteries already Start the Genny! I will have and On-Board Spare Battery with a Simple Manual Connect ( Like a Boat Switch) to elevate a complete Shutoff, f Everything, causing havoc. or a Reset, might work as well? Have you considered that, in your Circuit Perhaps? Or did I miss something?
Title: Re: Auto Low Voltage Shutoff Modification
Post by: RetiredGuns on January 26, 2019, 09:34:36 pm
http://vi.raptor.ebaydesc.com/ws/eBayISAPI.dll?ViewItemDescV4&item=112994047911&category=48618&pm=1&ds=0&t=1531362417000&ver=0 The included pic says 11.0 volts, Under load. This might be 12.2+- at rest. My guess is that if it needed to be higher to function properly, it would be . Ihad one and sent it back when my PSW inverter contained the same protection .
1000W 2000 Watt Power Inverter Pure Sine Wave 12V dc 110V 120V ac LCD Remote... (https://www.ebay.com/itm/1000W-2000-Watt-Power-Inverter-Pure-Sine-Wave-12V-dc-110V-120V-ac-LCD-Remote-RV/232635463941?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649) I have not encountered the low voltage cutout. The lowest Ihave seen is 12.3 . I fire gen set at 12.4 .
Great Prices, but overly fantastic claims also! I loved this part...... "For Inductive Load If connecting with inductive loads (e.g. Compressor, Pump, old CRT TV, Refrigerator, Ice conditioner, Air conditioner, Relays，Fluorescent lamp, Vacuum cleaner), please choose inverter whose rate power is 3-7 times higher than the load's rate power. For example, for a 150w refrigerator, please choose a 1000w inverter or higher; for a 800w air conditioner, please choose 2500w inverter or higher.
What is an "Ice Conditioner" anyway? I might want that! LOL
On that Undervoltage Device, you link had Specs, but all I could find, is the Chinese Link? Is there an Ebay seller perhaps. that I missed? Might work out? Thanks! Battery Low Voltage Protector 12V 100A (http://www.cosuperinverter.com/product/Battery-Low-Voltage-Protector-12V-100A.html)
Amazon no longer has them, either? 12 Volt, 100 Amp Low Voltage Battery Disconnect Battery Saver Battery... (https://www.amazon.ca/Voltage-Battery-Disconnect-Saver-Protector%EF%BC%8CExtend/dp/B076CDP6M3)
Can't ever see prices like that ever beat, though! Gotta give 'em that!
Title: Re: Auto Low Voltage Shutoff Modification
Post by: RetiredGuns on January 26, 2019, 09:56:57 pm
Hmmm, just came across this Nifty Device! One for each Circuit, or just remember to have the Boost Switch in the Off Position! BTW, I do have a Manual disconnect switch that the PO had installed! I use it too! PriorityStart! 12-Volt ProMax Automatic Battery Protector (https://www.speedwaymotors.com/PriorityStart-12-Volt-ProMax-Automatic-Battery-Protector,58647.html?sku=91064121&msclkid=5b45048b4c3c1c00ee3658c6571c9467&utm_source=bing&utm_medium=cpc&utm_campaign=SMI%20-%20Shopping%20)(CSE)%20(Bing)&utm_term=1100309973614&utm_content=Speedway%20%20(Jan7_2019)
This that Manual Starting Battery Switch! Worth having IMHO! 2pcs New Racing Master Battery Quick Disconnect Cut/Shut Off Safety Kill... (https://www.ebay.com/itm/2pcs-New-Racing-Master-Battery-Quick-Disconnect-Cut-Shut-Off-Safety-Kill-Switch/253217404351?hash=item3af4eef5bf:g:lKsAAOSwyXNZ6bOg:rk:22:pf:0)
Title: Re: Auto Low Voltage Shutoff Modification
Post by: Jack Lewis on January 26, 2019, 10:52:38 pm
Hmmm, just came across this Nifty Device! One for each Circuit, or just remember to have the Boost Switch in the Off Position! BTW, I do have a Manual disconnect switch that the PO had installed! I use it too! PriorityStart! 12-Volt ProMax Automatic Battery Protector (https://www.speedwaymotors.com/PriorityStart-12-Volt-ProMax-Automatic-Battery-Protector,58647.html?sku=91064121&msclkid=5b45048b4c3c1c00ee3658c6571c9467&utm_source=bing&utm_medium=cpc&utm_campaign=SMI%20-%20Shopping%20)(CSE)%20(Bing)&utm_term=1100309973614&utm_content=Speedway%20%20(Jan7_2019)
This that Manual Starting Battery Switch! Worth having IMHO! 2pcs New Racing Master Battery Quick Disconnect Cut/Shut Off Safety Kill... (https://www.ebay.com/itm/2pcs-New-Racing-Master-Battery-Quick-Disconnect-Cut-Shut-Off-Safety-Kill-Switch/253217404351?hash=item3af4eef5bf:g:lKsAAOSwyXNZ6bOg:rk:22:pf:0)
I bought a new 2009 Honda Civic, top of their line, for $21,000. I was shocked to find out it did not auto shut off headlamps which all my Toyota vehicles had since 1992. So I bought one of these, and also recommended one to a friend for their Honda. Both failed a little over a year later. If you do install one, be prepared for a failure. When it faiiled of course it failed open, so no power. Also, since the Honda had such a small battery, it would shut off the 12V if you left the radio on while filling the fuel tank, necessitating resetting the theft code. Overall, not a good experience.
Title: Re: Auto Low Voltage Shutoff Modification
Post by: RetiredGuns on January 26, 2019, 11:55:03 pm
I bought a new 2009 Honda Civic, top of their line, for $21,000. I was shocked to find out it did not auto shut off headlamps which all my Toyota vehicles had since 1992. So I bought one of these, and also recommended one to a friend for their Honda. Both failed a little over a year later. If you do install one, be prepared for a failure. When it faiiled of course it failed open, so no power. Also, since the Honda had such a small battery, it would shut off the 12V if you left the radio on while filling the fuel tank, necessitating resetting the theft code. Overall, not a good experience.
Thank You for that First Hand account, Jack! That crosses that off the List then!
Title: Re: Auto Low Voltage Shutoff Modification
Post by: RetiredGuns on January 27, 2019, 12:38:14 am
I just came across this, and although it has a Built in 10 Min Over-ride capability, which is Perfect, it only has 65 AMP Continuous? I have 160 AMP Alternator, that may work with it, Possibly? Anyone see a conflict there? Might work, but the Studs also only take 1/0 Wire, and I have 2/0, installed. I realize I could trim it a bit, but don't want a fire hazard either? Blue Sea Systems® 7635 - Low Voltage Disconnect with Remote - BOATiD.com (https://www.boatid.com/blue-sea-systems/low-voltage-disconnect-with-remote-mpn-7635.html)
Title: Re: Auto Low Voltage Shutoff Modification
Post by: Old phart phred on January 27, 2019, 01:44:28 am
Blue sea makes some great products, if your start battery is dead mid ocean it's not like you can call AAA for a jump. If anybody knows bulletproof systems this company can help you out. I bought a cole-hersche smart isolater that prioritizes the engine start battery charge via peak voltage state first whether power from my alternator or my 3 stage smart converter,/charger on shore power then switches to charge house batteries to voltage peak. So far so good, but I have not boondocked for an extended period as the isolater holding coil burns an amp or two power to operate. May well have an Achilles heel that will bite me in the butt. Much smarter/experienced campers out there than me.
Title: Re: Auto Low Voltage Shutoff Modification
Post by: wolfe10 on January 27, 2019, 09:53:18 am
Tom,
That would work if installed in the line to the "salesman switch" (manual or solenoid) but would definitely not work for any inverter installations.
Said another way, 65 amps capacity should be enough for "normal" 12 VDC draws (verify draw if you have the 12 VDC air compressor for air leveling).
But, with an inverter/charger, both on charging and inverting, you could draw/pass through well more than that.
Title: Re: Auto Low Voltage Shutoff Modification
Post by: RetiredGuns on January 27, 2019, 05:21:32 pm
That would work if installed in the line to the "salesman switch" (manual or solenoid) but would definitely not work for any inverter installations.
Said another way, 65 amps capacity should be enough for "normal" 12 VDC draws (verify draw if you have the 12 VDC air compressor for air leveling).
But, with an inverter/charger, both on charging and inverting, you could draw/pass through well more than that.
Yes Sir, those were my exact thoughts as well! The "Salesman Switch" basically does the Function of Eliminating the DC Draw, manually, but in the event let's say if it was forgotten about the draw would be stopped Automatically! Guess that would be the best placement anyway, but would like it Incorporated in the Entire Loop, of course! The Inverter does take care of the AC Shutoff, but not DC of course!