Have 2 newer red top start batteries, rebuilt stock alternator, on the road the batteries and everything works fine.When parked at
home with 50amp to coach the start batteries eventually whittle away to not being able to start engine.
My question Is is this the isolator leaking voltage or some other component?The isolator is the stock red one but thinking of
replacing .Probably good idea to change start solenoid when changing isolator.
OE, there is no provision for charging the chassis battery from shore power.
Add one!
Several good options:
1. A smart "thief" device such as Xantrex Echo charger
2. A smart stand-alone small amp charger dedicated to the chassis batteries.
3. Manually using the battery boost switch (not my favorite).
4. If battery banks in the same location, using a battery booster cable between chassis and house battery positives (also not my favorite), as touching either end of the cable to any metal will cause a DEAD SHORT, sparks and extreme heat (think arc welding).
Mounted a Optima Model 400 charger/maintainer. on the side of the bed under the skirt. Ran wires under bed top to the batteries and plugged it in in engine compartment. Has worked great for over 2 years. Chassis batteries are Red Tops.
John
Agree with Brett but, still trying to figure out why the batteries are draining down, you would think it would be the same as a car
and last for weeks and be able to start.I have the charger designed for the red tops.
John,
LOTS more parasitic loads in a DP than a car.
Please clarify-- do you already have a separate charger for the chassis batteries?
How long does it take to discharge the batteries? Lots of small parasitic draws on the engine batteries. Install trickle charger so when plugged into shore power, the engine batteries are kept up. It's not good to repeatedly deep discharge the engine batteries. I just used the 120V outlet by the bus panel and then ran the charger wires a few inches to the panel. When I'm plugged in, the engine batteries are charging. I installed a couple of digital voltmeters where the Audit CRT was so I can monitor voltages all the time. The bus has both the house and engine battery cables/connections so you need to choose the correct one. Trickle charger costs $20 at HF. Has worked well for years. Simple and effective. Takes only a couple of minutes to install.
Do NOT use the boost solenoid!!!
Rotate the bus attachment 90 degrees CCW as somehow it uploaded wrong.
Pierce
I have a separate charger but just use it to recharge the batteries when they get low.
Guess I'll just leave the maintainer on when at the house,I have a outlet just forward of the rear wheel well, already have the
plugins on the batteries.
John,
You have several ghost voltage draws. Here is a short list of the big draw items,
Engine ECM, Trans. ECM, dash radio, HWH controller along with several smaller draw items that do add up a lot more than a car system.
Pamela & Mike
Sorry about the photo. Here is how I mounted the trickle charger. Engine battery voltage is the bottom and readouts are while parked with solar contoller in "bulk." Trickle charger is on 24/7.
As I have mentioned a few times on forum I have a 70watt dedicated solar panel going to a small controller bedside then to start batteries. Never an issue starting BUT if parked indoors this of course will not help you much it will work if you are outside.
JohnH
I have been using mine - someone please make sense to me why I should not....
thanks much,
Jim
Three amp continious draw to electrically hold the boost solenoids together.
You aren't the only one, but I've read that many people use it report no problems.
Potential problems of Boost button are:
1. If you lose power to the coach and don't realize it for a month, your house batteries and chassis batteries could drain each other to the point of battery damage.
2. If the float requirements / settings of your charger (theoretically, set to match your house battery) are not compatible with the chassis batteries, you could be decreasing the lifespan of the chassis batteries via overcharging.
Personally, I had my cat step on my boost button while I was gone for the weekend (and the coach was not being charged), and by the time I returned my house batteries were under 11V. Not good. So I try to stay away from the boost switch.
One more reason to not use boost, it does wear out then not there when you need it.
The boost solenoid also draws a lot of juice just at idle. If you don't think so, put your hand on it when it's been on an hour. At best, it's an inefficient way to charge a battery plus the reasons on the post above. Unattended, any solenoid that gets hot has the potential of getting a lot hotter. Cole-Hersee has changed the point material several times trying to get better reliability. Use it for what it is intended for, adding some amps to the start battery for severe condition starting and also as a backup in case the alternator fails and you want to get home. Crying wolf too many times may mean it won't work when you need it most.
Pierce
Thanks much, folks, Does a continuous duty solenoid draw less current?
Jim
No, to eliminate the current draw, you would need a latching solenoid. Continuous duty means you can leave it on for an extended period without reducing it's life or overheating it. An example might be to use a solenoid to turn on high draw driving lights. A lighter duty solenoid might stick and leave the lights on. I had a couple of aircraft landing lights on my car for night driving in Mexico and had the solenoid stick. Bad deal. Latching solenoids are found on our coaches to operate the water pump.
Here is an example of a 110 amp latching solenoid: Cole Hersee 24200 SPST Latching Solenoid 12V 110A Continuous Duty (https://www.waytekwire.com/item/77025/SPST-Latching-Solenoid-12V/?gclid=Cj0KEQjwtu3GBRDY6ZLY1erL44EBEiQAAKIcviQ8F6s4dgbV47WlmiHRPMqcmw0hGsBlQgaJPzk3xAAaAv4F8P8HAQ)
Pierce
I greatly appreciate the schooling - and the link!
Jim
This has my vote for a 100% fix of your problem:
Ultra TRIK-L-START Starting Battery Charger/Maintainer (http://www.lslproducts.net/TLSPage.html) Quick and easy to buy & install.
$30 and you are good for the next 100 years:
LSL Products TLS-OEM 5 Amp Starting Battery Charger (https://www.rvupgradestore.com/Ultra-Trik-L-Start-p/tls-oem.htm) Everyone needs this or something similar or start batteries will always run down over time.
Barry has it right. Spend a little money and time now or let your expensive bank of batteries go flat and then try to bring them back up.
Pierce
Tri-L-Start gets my vote also. I have three Optima Blue tops for starting batteries. I've used the Trik-l-Start for 5 years and have instant starts and never had a problem. About $600 bucks for starting batteries maybe overkill but my batteries sit on the back bumper behind the big Detroit. The Blue Tops are designed for the marine environment and will take a lot of punishment, but I want to make sure they stay at maximum cranking capacity.
I also use a cigarette lighter digital voltage tester as recommended by Pierce. Before I turn the key I can instantly check to make sure the voltage is good before engaging the starting system. It takes a few seconds with the key in the first position to power up the ECM and to run it's checks before the check engine light goes out. About 15 seconds later for the for the 12v vacuum pump for the dash to cut-off. At that point I engage the starter. Low voltage is not good for electronics. Very inexpensive and well worth it!
Jerry
I also recommend the TriklStart. Cheap and effective. I think your setup is the same as mine. You can mount it right in front of the isolator. Easy hookup to the isolator.
jor
I went with Johns solar approach right down to his install recommendations. But also a maintainer that is not hardwired into system from HF. So far never use the HF since we added the solar panel. I do monitor it with a plug in digital meter.
X4. Mounted mine on one of the batteries, so I can see it when I open the bay door. Wires connect at the isolator. ^.^d
I was put going to put in a charger and then I found out about Amp-L-Start and Trik-L-Start and just installed the Amp-L-Start and it works great and simple to install.
With a total discharge my 30 amp crossover charger blew a fuse trying to charge the engine batteries.
No indicator shows this.
Same with trick l charge
My guru gave up,on them and now uses a full amp combining relay like the new coaches use.
Can tske full 130 amp current
Thanks for this useful discussion. However, this talk is limited to a plugged-in condition. We don't do much of that except when home. I am not happy to learn that I have been abusing my Boost Solenoid all these years. Additionally, perhaps I have ascribed abilities to the Boost Switch circuitry that it does not deserve.
Four years ago, I added 400 watts of solar charging from panels on the roof. (Brought the cable in and down that hollow wooden post behind the driver's seat. Installed the controller on the wall between this post and the driver's window. Then continued down the wooden post, through the floor, to the Coach batteries.) I ASSUMED that by selecting the Boost ON, the Isolator would charge the battery-bank that needed charging the most. Thus, bouncing back and forth between the Start and the Coach banks, to bring up both banks as needed in a "stair-step" progression. Now I wonder about the validity of that idea. (But it does sound nifty.... The "bouncing back and forth"was the saleman's explanation of the Boost switch function.)
Have noticed that Start batteries were always lower voltage when parked inside and not plugged in. This has me considering a cutoff switch (also a theft deterrent perhaps) for the Start batteries. The Trick-L charging thingy would solve (most) of my concerns when parked at home or a campground.
My U270 came with two start batteries. The storage area for start batteries was large enough to hold a third. I reasoned, an additional battery and a couple of cables are much cheaper than a starter. So, when it was time to renew the Start batteries, I installed three.
Same setup. Worked well so far for about 5 years.
Jerry