| Author |
Message |
Wayne Buttress (Flyingb) (66.52.189.26)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, December 23, 2001 - 7:00 pm: | |
Thanks for all the input on separating house and starting battery banks. I'm learning alot.
I would like to discuss the different systems for serparating the 2 banks while charging from the alternator. Is there a reason for not using a simple(KISS) solenoid as opposed to a "combiner" or isolator. If the solenoid would work OK then would I have to buy one to match up with a 300amp alternator? Where can I buy one? |
DrivingMissLazy (65.207.109.5)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, December 23, 2001 - 9:25 pm: | |
I have an isolator in my system, however if I were doing it again, I would use a solenoid. I do not like the isolator as the alternator is sensing the output voltage of the alternator, not the actual voltage going to the start or house battery. If you connect the alternator to sense the start battery, then it does not know the state of the house battery, or vice versa. Some alternators do not permit selecting the source of the sense voltage. They can only sense the alternator output. Also there is a small voltage drop across the isolator, which is not good.
In connecting the solenoid, I would energize it thru a normally open contact oil pressure switch so that the batteries are not connected until the engine is actually running. Otherwise you are trying to crank the engine thru the solenoid contacts and the wiring to the house batteries. They are not rated for this amount of amps.
I believe the original bus heat A/C blower solenoid is probably adequate. I feel it and the wiring to the house batteries should be rated for about 150 amps. Luke at US Coach can probably supply you with an adequately sized solenoid.
Richard |
Steve Fessenden (63.27.89.201)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, December 24, 2001 - 12:09 am: | |
If you don't use the oil switch, you can use the solenoid to boost your start batteries if they get low. I've had to do that several times. Just wait a few minutes to allow the start batteries to charge from the house batteries so that the the solenoid is not having to carry all the current. I also have a separate solenoid to connect the generator battery to the house battery 12 volt terminal. (My system is 24 volts and I have an equalizer. I believe yours is 12 volts only.)
Consider putting in a separate alternator to charge each set of batteries and having solenoids so you can charge all batteries off either alternator or charger (inverter). True reduncancy
so one bad alternator is not a trip stopping catastrophe. |
DrivingMissLazy (65.207.109.5)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, December 24, 2001 - 6:50 am: | |
Good idea. I forgot the emergency jumper switches that I have. It is a single pole spring loaded toggle switch and gets power direct (not from the oil pressure switch) and allows connecting the house and start batteries together even with the engine not running.
My genset emergency jump switch connects the genset battery to the start batteries so that I can get the genset started, even if the start batteries are low. Once the genset is running you then have AC power for a battery charger or whatever.
Richard |
Steven Gibbs (12.148.43.6)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, December 24, 2001 - 7:18 am: | |
Wayne,
I went with the same system that most manufactures use in regular motorhomes. If you visit www.intellitecsve.com you will find a whole line of battery control solutions.
The battery control center is designed to manage two battery systems and incorporates the emergency start function also.
You can download all of the service and installation manuals from the website and compeletly design your system prior to ordering anything. |
Rodger Manecke (Rodger) (63.11.248.75)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, December 24, 2001 - 11:00 am: | |
The system on my '76 Prevost is simple. The 24V engine starting/exterior lamps system is completely separate from the house 12V/120V system. The genset starts off the house batteries. If the house batteries should become depleted, I can jump the genset off the toad battery or a small emergency jumpstart battery I carry along.
If the 24V starting batteries get too low to start the engine, I can charge them with a portable automotive 12V/24V 10 amp charger, powered by the house system or "shore power" if available.
When running high draw items like the air cond when underway, I run the genset. It burns under 1 gph and needs the exercise anyway.
When the bus generator failed, it was replaced with a smaller 24V truck alternator belted off the old air conditioner pulley.
This has worked fine for me for almost three years.
Happy Holidays everyone,
Rodger |
Steve Fessenden (63.25.54.129)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, January 08, 2002 - 11:08 pm: | |
Coleman generator-charger: 45 Amps at 24 volts or 90 amps on 12 volts or 1000 watts on 110 volts AC. Small, light, portable. If someone were acutally buying a small generator for battery charging that would be a dandy item. Could recharge that old bus you are thinking of buying so you could try it out on the first visit.
Steve Fessenden |