Reply
 
Thread Tools Display Modes
 
Old 01-07-2020, 10:52 PM   #1
Bus Nut
 
Phatman's Avatar
 
Join Date: Jan 2015
Location: Brazoria County, Texas
Posts: 327
Year: 1997
Coachwork: Carpenter
Chassis: International
Engine: T444E
Rated Cap: 32 Passenger
Battery isolators

I would like to get some opinions on battery isolators. Diode or solenoid? And why. Thanks in advance for your time.


Watch the police & the tax man miss me, I知 mobile !!
Phatman is offline   Reply With Quote
Old 01-08-2020, 01:49 AM   #2
Mini-Skoolie
 
Join Date: Apr 2015
Location: Wisconsin
Posts: 23
Year: 1997
Coachwork: BB
Chassis: TC2000
Engine: 5.9
Rated Cap: 78
During our build, we used a Stinger solenoid to isolate our house bats from our bus bat so we could use the alternator to charge the house bats while driving. Simple switch to activate the solenoid. So glad we went that way, the Stinger went bad and we were in the middle of nowhere to get a new one. However, any old auto parts store has a " continuous duty solenoid" was a perfect fix, running it ever sense.
russsh is offline   Reply With Quote
Old 01-08-2020, 02:15 AM   #3
Bus Nut
 
Phatman's Avatar
 
Join Date: Jan 2015
Location: Brazoria County, Texas
Posts: 327
Year: 1997
Coachwork: Carpenter
Chassis: International
Engine: T444E
Rated Cap: 32 Passenger
Quote:
Originally Posted by russsh View Post
During our build, we used a Stinger solenoid to isolate our house bats from our bus bat so we could use the alternator to charge the house bats while driving. Simple switch to activate the solenoid. So glad we went that way, the Stinger went bad and we were in the middle of nowhere to get a new one. However, any old auto parts store has a " continuous duty solenoid" was a perfect fix, running it ever sense.
Hey thanks for the info Russsh. Do you know what your solenoid amps is rated for? What is your house battery bank in amps?
Phatman is offline   Reply With Quote
Old 01-08-2020, 11:03 AM   #4
Bus Crazy
 
Join Date: Nov 2016
Posts: 1,352
Neither is my reco.

Unless your House bank is **only** getting charged by an alternator which is wired directly to the Start batt.

Which IMO is sub-optimal.

But if that is the case then $50 solenoid will indeed do the job.

Diode based isolators usually add too much voltage drop.
john61ct is offline   Reply With Quote
Old 01-08-2020, 11:11 AM   #5
Bus Nut
 
Mountain Gnome's Avatar
 
Join Date: Oct 2017
Posts: 514
Year: 1999
Coachwork: BlueBird
Chassis: TC1000 HandyBus
Engine: 5.9L 24V-L6 Cummins ISB
Rated Cap: 26 foot
So if I use a relay isolator, and drain down my deep-cycle AGM batts, when I run the motor and alternator, will the deep cycle batts pull amps from the starter batts?


The diode isolator website I looked at (trying to figure out what the hell that thing under my bus exactly was) says it will allow the charge from the alternator to go to the weak battery, without overcharging the full battery. I could also get one that isolates several batteries from each-other this way. That last option looks nice, since I will have 2 starter batts, and 2 AGM deep cycles.



Any comments on that?
Mountain Gnome is offline   Reply With Quote
Old 01-09-2020, 12:06 AM   #6
Mini-Skoolie
 
Join Date: Apr 2015
Location: Wisconsin
Posts: 23
Year: 1997
Coachwork: BB
Chassis: TC2000
Engine: 5.9
Rated Cap: 78
I believe the amp rating for the solenoid is 200 continuous. We have 4 6v golf cart house batteries, wired up for 12v. I have a switch to activate the solenoid manually so i can isolate the house and starter bats at will. Have a 5.9 Cummins which i think has a 160amp alternator, when house bats are down abit, i flick the switch while driving, the bus amp meter jumps to about 90 amps, and slowly goes down as the bats charge. Cool thing, if my starting bats gets low, i can jump it with a flick of the solenoid switch.

4 6v bats, 230ah, wired 2 in series to give me up to 12v bank, then in parallel to give me more ah time. 460 total ah, at 50% usable, 230 usable amps
russsh is offline   Reply With Quote
Old 01-09-2020, 12:09 AM   #7
Mini-Skoolie
 
Join Date: Apr 2015
Location: Wisconsin
Posts: 23
Year: 1997
Coachwork: BB
Chassis: TC2000
Engine: 5.9
Rated Cap: 78
BTW, we have an RV shore power 4 stage 90amp charger/conditioner for the house bats too. When plugged in, we can charge and maintain both house and starter batteries with that. 3 years full timing, seems to work. Solar is next on the never ending list!
russsh is offline   Reply With Quote
Old 01-09-2020, 12:10 AM   #8
Bus Crazy
 
Join Date: Nov 2016
Posts: 1,352
The whole point is connect when charging is happening, so current flows to House from the alternator not the Start batt.

Two batteries makes a single bank, treat as one unit.
john61ct is offline   Reply With Quote
Old 01-09-2020, 09:18 AM   #9
Bus Nut
 
Phatman's Avatar
 
Join Date: Jan 2015
Location: Brazoria County, Texas
Posts: 327
Year: 1997
Coachwork: Carpenter
Chassis: International
Engine: T444E
Rated Cap: 32 Passenger
Quote:
Originally Posted by russsh View Post
I believe the amp rating for the solenoid is 200 continuous. We have 4 6v golf cart house batteries, wired up for 12v. I have a switch to activate the solenoid manually so i can isolate the house and starter bats at will. Have a 5.9 Cummins which i think has a 160amp alternator, when house bats are down abit, i flick the switch while driving, the bus amp meter jumps to about 90 amps, and slowly goes down as the bats charge. Cool thing, if my starting bats gets low, i can jump it with a flick of the solenoid switch.

4 6v bats, 230ah, wired 2 in series to give me up to 12v bank, then in parallel to give me more ah time. 460 total ah, at 50% usable, 230 usable amps
What is the purpose for the switch to isolate at will? Is that so you can jump the start battery at will? I thought that the alternator from the bus charged both battery banks at the same time while driving and isolated them when plugged in on shore power? I hope I don’t sound like a freakin idiot ? Just a bit confused getting all my parts together.

Watch the police & the tax man miss me, I’m mobile !!
Phatman is offline   Reply With Quote
Old 01-09-2020, 10:15 AM   #10
Bus Geek
 
Join Date: May 2016
Location: Eastern WA
Posts: 6,123
Year: 2002
Coachwork: Bluebird
Chassis: All American RE (A3RE)
Engine: Cummins ISC (8.3)
Rated Cap: 72
They also make a MOSFET battery isolators. They have minimal voltage drop.

I have seen folks have good success with the unit from Victron.

They allow charging both batteries from your alternator but will not allow one battery to discharge the other.

I have seen folks with the solenoid solution and accidentally leave it turned on while camping. They ran their house batteries low and went to start the engine to recharge. Guess what? They inadvertently discharged their starting batteries also.

Regardless of which solution you choose some sort of safety should be in place to eliminate the possibility of accidentally discharging your starting batteries.
PNW_Steve is offline   Reply With Quote
Old 01-09-2020, 12:00 PM   #11
Mini-Skoolie
 
Join Date: Apr 2015
Location: Wisconsin
Posts: 23
Year: 1997
Coachwork: BB
Chassis: TC2000
Engine: 5.9
Rated Cap: 78
Quote:
Originally Posted by Phatman View Post
What is the purpose for the switch to isolate at will? Is that so you can jump the start battery at will? I thought that the alternator from the bus charged both battery banks at the same time while driving and isolated them when plugged in on shore power? I hope I don稚 sound like a freakin idiot ? Just a bit confused getting all my parts together.

Watch the police & the tax man miss me, I知 mobile !!
Couple of things, when building our bus, looking at bat isolators, wasn't impressed with the auto diode things, cost and not a fan of exotic hard to get on the road parts.....just my opinion. So we went with the solenoid route.

Over time, I have found that its a nice thing to connect both batteries, and to isolate them too at different times, I have the power to choose what happens to my batteries, i like that. HOWEVER! Someone just mentioned, if your not charging from shore power or solar, dont forget to isolate them batteries, dont want a dead starting bat!
russsh is offline   Reply With Quote
Old 01-09-2020, 04:51 PM   #12
Bus Crazy
 
Join Date: Nov 2016
Posts: 1,352
Yes the Victron FET based isolators are good but not cheap.

Any choice should be fully automatic in normal operation, nothing to have to remember. Solenoid switched from IGN voltage for example, if alt is the only charge source, or Starter needs no solar.

Manual override, like jumpstarting engine off House if Starter fails, fine but that's for rare events.
john61ct is offline   Reply With Quote
Old 01-09-2020, 06:44 PM   #13
Bus Nut
 
Join Date: May 2018
Location: topeka kansas
Posts: 607
Year: 1954
Coachwork: wayne
Chassis: old f500- new 2005 f-450
Engine: cummins 12 valve
Rated Cap: 20? five rows of 4?
switches, solenoids, and dead starting batteries

I have a book on my bus, the front few pages are check lists.... check tires, lights, walk around, yadda yadda yadda. part of the road trip check list says interconnect house batteries to alternator. Later this will be changed to .. connect mppt charge contoller to alternator. when the bus gets parked the check list says disconnect house batteries.....

check lists work -- only if you actually follow them. helps keeps airplanes in the air. most of those crashes happen because the check list was not consulted and followed.

want to avoid dead batteries..... start with a check list. confirm situation every time.

wonder how many ever the air pressure in the spare tire? when was the last time you put a pressure gage on the bus tires? check coolant? motor oil? rear differential oil level? brake inspection? inspect belts and hoses?

william
magnakansas is offline   Reply With Quote
Old 01-10-2020, 08:12 AM   #14
Bus Nut
 
Phatman's Avatar
 
Join Date: Jan 2015
Location: Brazoria County, Texas
Posts: 327
Year: 1997
Coachwork: Carpenter
Chassis: International
Engine: T444E
Rated Cap: 32 Passenger
It seems to me everyone has a good argument the way THEY do things on their bus that works for them. I really appreciate all of the input. A lot of food for thought. I have been out of touch with my bus for the last year, but I知 full steam ahead now. I知 determined to have BLUTO complete by the summer. Thanks everyone !!!


Watch the police and the tax man miss me, I知 mobile !!
Phatman is offline   Reply With Quote
Old 01-26-2020, 01:19 AM   #15
Bus Nut
 
Join Date: Dec 2018
Location: Mt Vernon, WA
Posts: 266
Year: 1996
Coachwork: Bluebird, Collins
Chassis: G30 Bluebird Microbird, E350 Shuttle Bus
Engine: 1995 Chevrolet 350, 1992 Ford 460
On the GM PD4106 I知 trying a Magnum Smart Battery Combiner to keep the Start batteries charged from the House batteries via alternator power, shore power, or solar power. Just got the new cables run today. Will be testing it out shortly.
Doktari is offline   Reply With Quote
Old 01-26-2020, 01:44 AM   #16
Bus Nut
 
Phatman's Avatar
 
Join Date: Jan 2015
Location: Brazoria County, Texas
Posts: 327
Year: 1997
Coachwork: Carpenter
Chassis: International
Engine: T444E
Rated Cap: 32 Passenger
Quote:
Originally Posted by Doktari View Post
On the GM PD4106 I知 trying a Magnum Smart Battery Combiner to keep the Start batteries charged from the House batteries via alternator power, shore power, or solar power. Just got the new cables run today. Will be testing it out shortly.
Post how it works out. If you can, give us a drawing of how you have it set up.
Phatman is offline   Reply With Quote
Old 01-26-2020, 08:36 AM   #17
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 12,627
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
will the device current limit to 25 amps? or if you end up with a dead house battery will it potentially over-load the device as a dead bank will likely want to pull more than 25 amps at alternator voltage..

-Christopher
cadillackid is offline   Reply With Quote
Old 01-26-2020, 12:46 PM   #18
Bus Crazy
 
Join Date: Nov 2016
Posts: 1,352
Which device are you asking about?

Note that most concerns about inrush over-current are baseless wrt lead banks.

A unit rated for continuous say 60A may be just fine with 400A for a brief time.

Lead batts have such high resistance they're basically self-limiting, any inrush surge does not last long.

Yandina combiners handle the issue very well (and cheaply) just by closely spec'ing the connection wires. She invented the product category (VSR / ACR) gives great support and a lifetime warranty.
john61ct is offline   Reply With Quote
Old 01-26-2020, 01:46 PM   #19
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 12,627
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
John the reason I ask is on my regular starter batteries, 2 group 31 12 volt AGM.. (batteries plus top brand whatever it is)... if I run them low... low enough that the engine cranks slow to start but still starts.. (with glowplugs on the dash gauge will read 10.7 or so)... my dashboard ammeter will go close to the peg of 150 amps and run there for awhile before it backs off slowly as the batteries charge up while im driving..



I realize you ardent supposed to run down the batteries that low but reality is that batteries will get run down that low...



thats why I was curious iof those devices limited the current or if they would just fry
-Christopher
cadillackid is offline   Reply With Quote
Old 01-26-2020, 02:10 PM   #20
Mini-Skoolie
 
Join Date: May 2016
Location: SFBA, CA
Posts: 33
Year: Any!
Coachwork: Self!
Chassis: Crown or Gillig!
Engine: Cummins 855, 400 HP or more!
Rated Cap: 36,000 GVRW
My Opinion, solenoid uses more energy than diode. The BEST way to protect your start battery is to put a Cut-Off Switch inline between you motor and start batteries. When you 'stop and stay', cut-off the batteries altogether! If you have a solar trickle charger, on the start batteries, you insure that you can 'start n' run' when the mood suits you! Diode isolators are great for sorry free battery charging and use/lose less energy than solenoids and when the batteries top-off they switch over to charging the start batteries only. This provides an opportunity to use more exotic batteries for the RV with things like Lithium and *BMCs to control precise charging profiles. BMC = BATTERY MANAGEMENT CIRCUIT
BigPaul367 is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 11:38 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
×