2015 IH--Boost switch?

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2015 IH--Boost switch?

October 17, 2022, 11:18:03 am

To the extent a 2015 IH is similar to older FTs, I have a question about the dash boost switch? Think I understand the basic function of the boost. Dash switch and solenoid seem to have three positions/functions: light switch off; light on, and light blinking. My switch is a two-position on/off, intermittent rocker--basic function is to connect chassis and house bats in the event chassis bats are low. Also assume that: 1- the large blue isolator in engine compartment uses diodes to control/isolate bat banks while engine is running; 2- boost solenoid also performs a BIRD function to charge chassis bats from inverter/charger while on shore power. 3- bat banks remain isolated while on shore power when switch is off.
So, do I push switch to boost bats or do I have to hold switch [momentary] down to boost? If light is off, is boost and "BIRD" function disabled? If light is on is the switch boosting? If light is blinking, is the BIRD function enabled to charge chassis bats as needed? Thoroughly confused at this point!

Re: 2015 IH--Boost switch?

Reply #1 – October 17, 2022, 11:45:40 am

When the light is on the boost is on. The boost light blinking I think something is not right
but you have a newer coach then me so some else might know what that is.

Re: 2015 IH--Boost switch?

Reply #2 – October 17, 2022, 02:28:34 pm

Since your and my coach are close in years I believe the wiring is close to the same. I know when I look at different years Foretravel moved items around to different locations in the bays.

When you are driving down the road the 300+amp alternator and the big inverter (diode) in the back right is charging both your coach (6 batteries) and chassis (3 batteries) When going down the road the dash gauge is showing 13.9-14.00 volts If the second AC unit is running (when on inverter, generator off) The dash gauge will go down to around 13.6 when idling.

When you are plugged into shore power the two outback chargers/inverters charge up coach batteries.

From what I can see in the drawings the chassis batteries are only charged when the auto boost switch is on. There is another wire going to the boost switch so at this time I do not know if the boost swich works as a 3 way switch and will operate the boost switch from another source. When I went to coach connected to shore power the boost switch was on. I have not gone and disconnected yet to see if it turns off once shore power is removed.

My coach has two remote control battery switches. I believe one is for killing house 12v power and the other combines the batteries. The boost switch on my coach is only a momentary switch You have to hold it in and when the light comes on the switch then the batteries have been combined. You can go to the switch in the compartment and turn it to on where you would then have both batteries tied together

Edited to correct what I had said after further investigation 10/20/22 8:43 PM

Re: 2015 IH--Boost switch?

Reply #3 – October 17, 2022, 04:19:44 pm

OK--lets try again--my bad! Went back and tested both issues--confirmed that #2 roof AC does work on inverter/bats. Earlier effort to "learn" about the inverter/charger control panel might have caused this issue. Also confirmed that manually turning solenoid switch to red-shaded position [not yellow] locks out dash switch and freezes switch in non-combined position. In either green-shaded position, dash switch will combine bat banks--will need two people observing to tell if pushing/holding the dash switch produces a different outcome from just leaving it in its nominal [un-pushed] position? Still wonder if there is a BIRD function for this switch, eg, based on certain voltage level parameters, is there a time when bat banks are automatically not combined?

Re: 2015 IH--Boost switch?

Reply #4 – October 17, 2022, 09:24:33 pm

If you are wondering if the batteries are combined without human intervention, I would say no, but would not be the first time Not sure what BIRD function is.

I believe the file I have attached is for the switch. It says it is manual on and off and remote on and off.

Re: 2015 IH--Boost switch?

Reply #5 – October 17, 2022, 09:52:36 pm

Thanks Jack--my switch is similar but has 4 cables attached. The LED description was interesting--but I have two modes where the LED flickers either fast or slow--could be fault codes? Many coaches have a battery charging system that automatically combines bat banks based on preset voltage levels--referred to as a BIRD. On our earlier IHs and older FTs, they use a diode isolator [large, blue heat-fin device] to separate bat banks while driving. Basically, you don't want/need the two bat banks combined 24/7, so a BIRD device would manage bat charging while on shore power or genset.
Other than maintaining battery health and longevity, the dash boost function isn't a big deal for me--never use it on last coach. Just want to better understand how chassis bats are charged while on shore power, and if this switch is involved?

Re: 2015 IH--Boost switch?

Reply #6 – October 20, 2022, 09:54:11 pm

I have modified my earlier post. Due to wanting to remove incorrect comments I had made.

After looking at my boost auto switch it was in the auto on mode with shore power connected. Looking at drawing the only way the chassis batteries can get charged from the inverter/charges is via the boost auto switch. I now also have questions as to if switch is changed from auto on to auto off by some automation in the switch or from outside source.

Re: 2015 IH--Boost switch?

Reply #7 – October 21, 2022, 08:32:59 pm

Today,
Unplugged coach. Checked boost switch. it showed Auto On.
Started coach, ran engine for a few minutes, checked boost switch, showed auto on
This afternoon after day of driving, shut off coach before connecting to shore power, boost switch showed auto on. I have never seen the switch in auto off.

Looks like when I get back home I will need to set up a temp switch to see if I have a bad auto boost switch or?

I have looked at my boost switch and have not been able to fine the model number of the one installed in the coach. If it is a BEP 720-MDVSO 12/24V Voltage Sensitive Switch then the switch will stay in auto on as long as voltage of either battery bank has a voltage of 13.3. If the voltage drops to 12.7 then the battery banks will disconnect. Since my batteries hold the high voltage when I disconnect from shore power it is possible I did not wait long enough for one set of batteries to get down to 12.7. If this is what I have and is how it works I have no idea why FOT put in a high $ high power isolator.

More to come after further investigating.

Re: 2015 IH--Boost switch?

Reply #8 – October 21, 2022, 09:17:05 pm

720-MDVSO 12/24V Voltage Sensitive Switch manual

Re: 2015 IH--Boost switch?

Reply #9 – October 25, 2022, 10:33:01 am

Appreciate the update--agree, our switches are a bit different from the manual you attached--but believe the answers to my concerns are in the specifications page. The switch auto combines at 13.3v, it auto disconnects at 12.7. In both cases, auto functions are bi-directional, so they occur if either bank meets the criteria. Also, interesting that pressing the dash switch will combine the banks, if not already combined; while holding the dash switch for 6 seconds will manually disengage the combine function, if already combined. This explanation was pretty much confirmed by Chad at FT yesterday.
Accordingly, the "normal position" for this switch seems to be--banks combined. This is pretty much contrary to my past experience with "boost" switches--thus my confusion. Also, seems like this auto switching system is somewhat redundant with our diode-based battery isolators that function while the Cummins is running, but there are probably charging situations dictating that both be used.

Re: 2015 IH--Boost switch?

Reply #10 – October 25, 2022, 11:07:55 am

Sounds like a SMART bi-directional relay/solenoid. Some of these "improvements" may require an advanced degree in electronics OR in video-gaming.

Re: 2015 IH--Boost switch?

Reply #11 – October 25, 2022, 11:19:44 am

Do you have a battery isolator. I'm thinking of taking my isolator out and putting a Blue Sea
relay that does the same thing as that motorized battery switch you have. That relay switch will
replay the isolator and the boost switch.

Re: 2015 IH--Boost switch?

Reply #12 – October 25, 2022, 12:13:28 pm

Quote from: oldguy – October 25, 2022, 11:19:44 am

Do you have a battery isolator. I'm thinking of taking my isolator out and putting a Blue Sea
relay that does the same thing as that motorized battery switch you have. That relay switch will
replay the isolator and the boost switch.

Yes, our coaches have a big isolator. Mine is mounted just inside the rear door on the left side. OldScout and I are not sure if the Silverleaf is telling the switch what to do or if the switch itself is doing it.

Yesterday OldScout disconnected from shorepower, switch was in auto on. He then turned on AC#2 that is on the inverter. After a little while the switch turned to auto off. The one thing we do not know is if the switch did on it's own or if Silverleaf called to the switch to go to auto off. For some reason Foretravel has also included a large battery isolator so we are guessing the auto switch will turn off when the cummings is running but I have not verified that is happening. I am thinking the switch is in auto on when on shore power is to keep the coach batteries charged since in looking at the wiring diagram I see no other way for the chassis batteries to receive charge from the chargers.

Re: 2015 IH--Boost switch?

Reply #13 – October 25, 2022, 12:25:04 pm

If that switch works the same as the Blue Sea it turns its self on and off and it will turn on
when the alternator is charging.

Re: 2015 IH--Boost switch?

Reply #14 – October 25, 2022, 01:09:01 pm

I am afraid that due to my confusion regarding "boost" switch functions, this thread is kind of "much ado about nothing!" However, since the spec sheet suggests the relay switch will combine banks when both are at/above 13.3v, that means the banks will eventually combined when the Cummins is running. Guess the exception might be when house or chassis bank is below 12.7v, and the switch has disconnected banks. But if you start the Cummins, the diode-battery isolator [Old Guy--this could be an issue for your proposed "upgrade" unless Blue Sea is different] would connect the alternator to one or both banks immediately.
Brett is right--I am not smart enough for all this!

Re: 2015 IH--Boost switch?

Reply #15 – October 25, 2022, 01:17:58 pm

I have requested a full set of drawing from FOT today. Hopefully when I get them I will be able to figure out if the Silverleaf is telling the switch to turn on or off or if it is the switch it's self doing it. At this moment I have no idea what model switch OldScout and I have.

I do know the Silverleaf will shut off the water fill if (when) I forget to turn it off at 90% full water tank, so Silverleaf may be operating the switch also.

Re: 2015 IH--Boost switch?

Reply #16 – October 25, 2022, 01:44:54 pm

Quote from: oldguy – October 25, 2022, 12:25:04 pm

If that switch works the same as the Blue Sea it turns its self on and off and it will turn on
when the alternator is charging.

Lithonics makes a similar device more specifically for lithium battery banks. Charges the house lithium thru the alternator but incrementally so as not to overheat the alternator. Then will also switch over to charging the engine batts when on shore power. While also retaining all the function of the boost switch.

Off The Grid RVs in Quartzsite recommended it and installed it. After weeks on being on shore power it kept my engine batts up so I no longer deal with chargers on the engine batts.

Re: 2015 IH--Boost switch?

Reply #17 – October 25, 2022, 02:55:37 pm

Blue Sea relay won't work with lithium batteries so the tech told me. Good to see Lithonics makes
one for lithium batteries. With the Blue Sea Automatic Charging Relay the alternator is hooked up to
the chassis battery and when the voltage gets up above 13 volts for 90 seconds or 13.5 volts for 30
seconds the batteries are combined in the automatic position. It disconnects when the voltage gets
the voltage gets below 12.75 for 30 seconds and 12.3 for 10 seconds. There is electrical and mechanical
switch to over ride the automatic.

Re: 2015 IH--Boost switch?

Reply #18 – October 26, 2022, 08:48:28 am

oldguy--your description of the Blue Sea sound very similar to how my switch is functioning. Arguably, my switch seems to focus on the inverter/charge side, as FT also installed the diode-based battery isolator to manage alternator charging. By 2017, perhaps 2016, FT was installing a different switch [Blue Sea?] and had done away with the battery isolator. I have heard on other forums about installing a "DC2DC" programmable switch to protect the alternator as part of a lithium bat upgrade. My conclusion is that FT needed to install both the isolator and the boost switch, to cover all charging situations. Perhaps, as you suggest, the DC2DC switch covers both functions.

Re: 2015 IH--Boost switch?

Reply #19 – October 26, 2022, 11:24:50 am

The Blue Sea regulator also does the same thing when being charged by the inverter/charger
so the chassis batteries are getting charged also. I have ordered one and a Balmar Regulator
and will open a new link with the insulation.

Re: 2015 IH--Boost switch?

Reply #20 – October 26, 2022, 02:01:41 pm

Peter. So you have no plans for lithium batteries in the future?

Re: 2015 IH--Boost switch?

Reply #21 – October 26, 2022, 04:45:24 pm

No I have silicone batteries and they will probably out last me. They are great in the cold
and now have 1200 AH house batteries and 300 AH start batteries, don't the cranking amps, but
they sure turn the engine over fast.

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