Today I ventured to the backyard to inspect the Foretravel after a hard winter.
I knew the 3 Optima Red tops for start batteries were shot, there day was done last fall and I decided then that I would wait till spring to replace.
I wanted to start the generator and exercise it for a while, and try and start the engine using just the house batteries.
I first tried to start the engine, it barely turned over with the boost switch on. After about 5 seconds I gave it up. I then tried the generator and found it fired right up. My house batteries showed a 12.5v level at the dash monitor screen. The house batteries have been on the coach charger all winter (boost switch off).
Is it normal for the coach not to have enough battery power in the house bank (4 - 6V - T145 ) to turn the engine over alone (boost switch on but all 3 engine start batteries shot)?
In my opinion, it is best to turn on the boost switch, then wait a few minutes for the chassis batteries to take some charge before starting the engine. I have found the chassis batteries, even when so bad off they cannot turn the starter, still can lend a hand when given a temporary charge.they cannot hold that charge for long, but benefit from being closer to the engine.
Power from the house batteries will be limited by the wiring and the boost solenoid. The wires and boost solenoid will "boost" the power supplied for starting, but will be a fraction the power available from the direct wiring from good start batteries.
Good (BIG! and short as possible) booster cables from the house batteries to the start batteries might allow you to start from house batteries. Another option is to physically move one or more house batteries to the start battery position and connect battery cables to the transported house batteries. If the start batteries are bad, they may be sucking power rather than helping.
THANKS!
This was more of a "I wonder if" moment. NOT a true attempt to start the engine.
When it would not turn over the engine enough for ignition "I WONDERED" if It should have.
Sounds like this is normal.
I will go start battery shopping soon.
You didn't say whether or not you had a trickle charger on the start batteries over the winter. Easy to install one at the buss panel as it has an AC outllet next to it to plug it in. No need to install a charger at the start battery location. Depending on battery compatibility, you can also make a 4 or 5 inch small wire gauge jumper to go from the house to engine batteries at the buss while connected to shore power during winter. Have to make sure to remove it before starting the engine. I did that if we didn't go anywhere for a few weeks until I bought a high frequency trickle charger for the engine batteries.
Take the factory 12V schematic and have it blown up. You can then easily see the reason the house batteries won't start the engine by themselves. The schematic has all the cable sizes as well as the codes at the ends. Once you get aquainted with the wiring, it's easy to see the limitations.
Good idea to carry jumper cables in your toad or a car/truck at home. If the start batteries get low, it's easy (depending on the location of the start batteries) to just jump the coach running the toad for a few minutes before trying to start the coach. If the jumper cables are small gauge, just idle the toad for 15-20 minutes.
Pierce
The boost switch on my coach is rated at 200 amps. It will not start the coach alone as you just experienced. I have put a new groung and a wire directly to the starter as well and no longer need the boost switch to start. In fact it turns over much faster then it did before even with the boost swith on.
With a dead chassis battery, as Tom mentioned a few posts back, don't try to start right away. Before you flip the boost switch get the genny running, this will then power your converter (battery charger) for the house batteries. Now, flip the boost switch, don't try to start yet, and let the converter charge all batteries for say 30 minutes. Then with boost switch still on, try starting the engine.
Exactly!
Although the chassis batteries may be nearly dead, with maybe 30 minutes of charging, they can still add some Amps to what the House batteries can provide to the starter, even if their voltage is low.
It might take more than 30 mins if they are dead. Also if they are really low the batteries might be dead.
All six of my coach batteries are new, as is my towed car's battery, so I don't have much cause to worry, but that was not the case a few months ago. At that time, I started carrying a spare automotive battery and set of jumper cables in the house battery bay. Plenty of room on the floor and I can occasionally jumper it to the house batteries while on shore power to top it off. Still a Boy Scout...be prepared.
No, I pulled the plug on these batteries last fall. I milked them along for the tail end of the RV season here up north, by keeping a charger on them all the time except when driving. I knew there time had come but didn't want to buy new batteries only to have them sit all winter. I will buy new batteries soon (3, group 78).
I thank you all for answering my question, the house batteries alone can't be expected to start the coach with out help from the engine start batteries.
I appreciate the advice about how to use jumper cables to use the house batteries to start the engine and where to tap off the power.
My house battery bank is located all the way up front in the bay just behind the drivers window. The engine start batteries are located on the passenger side rear just behind the right rear wheel.
It would have been nice to have a de-sulfater plugged in over the winter to attempt to bring around the start batteries.
I'm wondering, if I'm the only one that carries a small generator? pc
We carry a honda 2000 generator, have for years and use it, especially when I am baking bread, just enough juice to handle the convection oven.
Roland
My coach came with a diesel gen so do not need another as I never use this one anyway!!
JohnH
I have two 2000's one a companion so you wire them together and get 3200 watts of 30 amp 110 and a honda 1000.
Belts and suspenders I guess.
They came by in deals new