Cruisers Forum
Main Forum => General Discussion => Topic started by: Ron Dittmer on May 03, 2020, 07:59:18 am
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After all these years, I am considering installing battery-disconnect switches on both the chassis and house batteries. I assume they are installed on the ground terminal.
You with experience with these, which design was most reliable? Which type would you avoid and why?
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I have been using a knife switch for almost 20 years on the chassis battery, never had a problem with it. On the coach batteries, I just use the switch that PC installs. For long term storage, I just disconnect the negative terminal on the coach batteries. There's not enough room for a knife switch.
I used to remove the coach batteries for long term storage and keep them on a quality maintainer but with the Lifeline batteries I use now, they're fine just disconnecting the negative terminal.
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Ron
Here is one I am considering. It was recommended from this forum. Rated 250 amps continuous and 750 amps surge at 12 volts
https://www.homedepot.com/p/Battery-Doctor-Knife-Switch-for-Top-Post-Batteries-20138/202931972
Like donc13, I have brand new lifeline batteries. Can’t wait to use them. They should be remarkably better then my previous batteries of which one just died other on life support.
Ron S
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In 2016 I had Kermit install this switch https://www.amazon.com/gp/product/B0070YEEI8/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 (https://www.amazon.com/gp/product/B0070YEEI8/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1) in lieu of the relay based switch which was standard with Phoenix. We had this delivered to PC during our build. I wanted to be 100% sure with the switch turned off the battery did not discharge due to known or unknown low current drain. I also wanted to be able to disconnect my solar charging system which this switch allowed.
Last year I wired up a toad which required the battery being disconnected from the car electric system. For this I installed a simple on off Blue Sea switch.
Both coach and toad Blue Sea switches have performed reliably. After Kermit installed the reference Switch in 2016 I think he made this standard for 2017 and later models. If I am correct that this is now standard, owners of newer coaches may have comments on reliability.
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You can't go wrong with this one as long as you connect it tightly. $7 tops. I've had many over the years. This disconnects the ground by turning the green knob.
https://www.harborfreight.com/battery-disconnect-switch-97853.html?cid=paid_google|||97853&utm_source=google&utm_medium=cpc&utm_campaign=&utm_content=&gclid=Cj0KCQjw17n1BRDEARIsAFDHFezVmXT0PyiokqSIZ8JnD0EvydnzvqEWcgJxErBhMdJ78wV67X6MnGsaAkGwEALw_wcB
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All boats have a battery disconnect switch. I would look at a marine switch if I were to install one. I’m sure the west marine website has a good listing of switches
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Thank you all for your replies to-date.
I should have been more specific. I am considering a battery post mounted disconnect switch for the chassis battery, and a screw terminal mounted disconnect switch on the house batteries. I use the posts on my house batteries for easy-access external charging. I no longer have a battery tray so the posts on my sealed AGM batteries are great for that as shown in this picture.
(https://live.staticflickr.com/7696/17305883992_94b0e41c0b.jpg)
Panel mounted switches like fandj had installed during the construction of his rig, and those sold at West Marine would be ideal, but for me with my PC, that requires more installation effort than I am willing to consider at this time.
Are there any other battery mounted switches aside from the blade and dial type? I worry the dial may come loose and the pivot on the blade will be an issue over time. You know how it is......problems never surface at the right time, place, and circumstance.
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Thank you all for your replies to-date.
I should have been more specific. I am considering a battery post mounted disconnect switch for the chassis battery, and a screw terminal mounted disconnect switch on the house batteries. I use the posts on my house batteries for easy-access external charging. I no longer have a battery tray so the posts on my sealed AGM batteries are great for that as shown in this picture.
(https://live.staticflickr.com/7696/17305883992_94b0e41c0b.jpg)
Panel mounted switches like fandj had installed during the construction of his rig, and those sold at West Marine would be ideal, but for me with my PC, that requires more installation effort than I am willing to consider at this time.
Are there any other battery mounted switches aside from the blade and dial type? I worry the dial may come loose and the pivot on the blade will be an issue over time. You know how it is......problems never surface at the right time, place, and circumstance.
Ron,
Sure, the pivots on the knife switch could break and the temper on the connection side (that the knife side slides into) could go bad so the knife no longer makes good contact.
Hugely unlikely though. As I said, I have been using a knife switch on my chassis battery for about 20 years now (OK, 3 knife switches over 3 RV's) and have had zero problems. Nor have I heard of anyone having problems. Doesn't mean no one ever had a problem.
If you ever did have an issue with one, it's a 5 minute job to remove it and put the negative cable back directly on the battery.
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The knife switch I mentioned below is out of stock. The one at Walmart is out of stock. What the heck! I thought the run was on toilet paper!
Ron S
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After all these years, I am considering installing battery-disconnect switches on both the chassis and house batteries. I assume they are installed on the ground terminal.
You with experience with these, which design was most reliable? Which type would you avoid and why?
That is a REALLY good question !!
1st try: The one with the green knob from Harbor Freight didn't work because the diameter of the post is only 0.53”, too small for the Ford battery cable clamp.
2nd try: I bought a knife switch , but the cast or sintered metal clamp was too small to fit over the (-) battery post and cracked when I tried to spread it. Also the 2 screws that fasten the metal parts to the flimsy plastic base were loose. I returned the POS to Autozone for a refund.
3rd try : I ordered this really clever design. It appears to be more robust than the flimsy knife switch, and looks promising because the perpendicular rotating post places the battery cable close to the (-) battery post with no twisting.
https://www.amazon.com/LotFancy-Battery-Disconnect-Switch-Trucks/dp/B07YFWCSYV
Updated 2o2
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I have been using the same type disconnect 2 Lucky shows above for almost thirty years on various rigs and other vehicles and have never had a problem with them. I started using this design so long ago that they were actually made in USA!
Paul
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One more consideration for the chassis battery disconnect, when starting the engine, 100% of the amperage needed to turn over the engine must be carried by the switch. In cold weather that amperage can easily exceed 500 amps until the engine actually starts. Typically, that's only for 5 to 10 seconds.
So whatever switch you decide on, make sure it can carry that load without blowing out like an overloaded fuse.
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So on the house batteries I would need Two disconnects being there are two ground cables?
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I understand that there is and/or could be issues with the on board computer being turned off for an extended amount of time. Has any one had any issue with this? Or is this not a concern?
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I understand that there is and/or could be issues with the on board computer being turned off for an extended amount of time. Has any one had any issue with this? Or is this not a concern?
I've always started (and if possible driven) any stowed vehicle at least once a month, for a variety of reasons. Most likely it is done partly to keep the "brains" awake. And remember to fire up the generator too as recommended, which is why you should use an all-season viscosity oil.
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So on the house batteries I would need Two disconnects being there are two ground cables?
No, just put a single knife switch with battery neg post on one side of switch and the 2 negative wires on the other.
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DOH!
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So, what did you end up with?
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I decided to continue living without either battery disconnect switch for now. Part of the reason is that I have been burned from other inferior (but less critical) China-made parts. Battery reliability is too important to me. It's not worth any loss of sleep wondering if I'll regret installing one. I will continue to use an 8mm wrench on the chassis battery ground terminal and leaving the house connected as I have been doing since switching to AGM batteries 5 years ago.
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Ron, you don’t use your rig that often to bother with it any differently than you are now. For those that use their rigs frequently it’s a nice feature for those 4 -6 week breaks between uses.
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For those that use their rigs frequently it’s a nice feature for those 4 -6 week breaks between uses.
I understand the logic in having them. A battery disconnect switch is not a bad idea. It's just not for me....not yet anyway. I might have considered the turn-knob one for the chassis battery if I knew they were top quality. I kind-of like the concept in the design of it. But with my luck, our rig would shut down in the worst of driving scenarios.....I imagine opening the hood to find the plastic knob cracked in half.
I completely lost faith in stuff made in the orient.
Our top level LG front load washing machine is the most ridiculous investment because it uses so little water that the clothes don't get clean. I got around that problem by increasing the amount of water through adjusting a gizmo, just to learn that the main drive motor can't handle the increase in weight that does not require much extra effort to slosh.
Our top level Kenmore Elite fridge also made by LG, has a new "Linear Technology" compressor. The fridge lasted us 5.5 years. We got lucky. Most people replace the compressor during the warranty period and then it lasts just long enough beyond the warranty period, never getting near 5.5 years of use.
Needless to say, we are 100% done with everything LG. Unfortunately I don't believe the other brands are any different. The best solution is "avoidance" where applicable as in the case with the battery disconnect switch.
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Ron, my thought didn’t take the China side into account. Even if it was made in the states would you have a need for one? When you don’t use something often it’s some times easier to do just as you are with say the battery terminal. I know I would.
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Sorry Ron, but the turn-knob battery disconnect like I recommended is not an appliance. It is a solid piece of brass with an electrical connection that is activated by a plastic knob, yes, but if the knob failed, the connection would not. I've had these for decades on every vehicle that should have one with no problem. It is the easiest, most efficient way to do the job...wish had I thought of it first, I'd be proud (and have a few more dollars to play with.)
Sure, you can get out a wrench and disconnect the ground cable and do the same thing I do by turning a knob.
Your choice. If you don't need one because you don't use it enough, great. But how about next year if you do use it a lot, or as a selling feature if you are done with it altogether? You've got seven dollars to lose to prove me wrong. My wife would say it is worth it.
Dougn
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After visiting 2 auto parts stores in my small town, neither had a cut off. Ended up with amazon delivering my 2 pack sometime this morning. Really don’t see in how they are constructed that there could be much of a problem. Though brass looking a scratch test will determine that. Now if my trik l start will ever get here?
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I'm not understanding the concern about failure. If it fails you spend a few minutes with a wrench, take it off and put the cable back on to the battery directly. It's no different than having a dead battery. Am I missing something?
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Mine came in today. Twist knob top. Packaging indicates came from Brazil ??? Appears to be brass in color only. A few scratches with a knife and bare metal underneath. But, 2 for less than $10.
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Appears to be brass in color only. A few scratches with a knife and bare metal underneath.
That was another concern of mine. I will stay with the Ford connection for the time being.
My good battery charger has a similar condition with copper plating over cheap metal. I am always using sand paper to clean it up. I don't want to introduce something similar to my chassis.
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I'm not understanding the concern about failure. If it fails you spend a few minutes with a wrench, take it off and put the cable back on to the battery directly. It's no different than having a dead battery. Am I missing something?
I am not concerned of the failure itself, but rather the timing of the failure. I main concern is a failure while driving.
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Installed my twist off yesterday. It has already come in handy on the on/off trik l start install. Pay attention to the configuration of the 2 connecting points orientation when you shop. Made a tight fit on the one I got.
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I'm not understanding the concern about failure. If it fails you spend a few minutes with a wrench, take it off and put the cable back on to the battery directly. It's no different than having a dead battery. Am I missing something?
I am not concerned of the failure itself, but rather the timing of the failure. I main concern is a failure while driving.
Obviously your choice:however, if you are driving... Your alternator will keep the engine going just fine. Once you stop and turn engine off, then it won't start until you fix the ground.
Don