Boost switch

Topic: Boost switch (Read 2525 times) previous topic - next topic

Re: Boost switch

Reply #25 – December 16, 2021, 12:24:56 pm

I've used the jumper to keep both the conventional engine batteries charged as well as the AGM coach batteries since 2008. It's plugged in 24/7 while parked at home, only removing before I start the engine. The twin voltmeters are worth their weight in gold as they keep an eye on the alternator, batteries, etc while driving and while parked. They also stay on 24/7. The are fused at the plugs and each end of the cable has a 5 amp fuse so there is no chance of a fire. The Progressive Dynamics converter does an absolutely perfect job of keeping the voltage right around the advertised 13.2 volts. I plug both in at the same time as one end can become electrically hot and could pop a fuse if it touches the ground on the other plug.

No idea where the white specks came from in the photo.

Pierce

Re: Boost switch

Reply #26 – December 16, 2021, 12:41:14 pm

Doug the makes perfect sense using your boost switch with the generator running
as depending on you inverter you get a lot of amps while starting and probably the
grid heater won't use any amps from the batteries. I made up my own thing for
charging the chassis battery which I can get up to 80 amps from the house batteries
for starting.

Re: Boost switch

Reply #27 – December 16, 2021, 01:34:07 pm

Brett,maybe revise the statement to no way to charge while not running.

Re: Boost switch

Reply #28 – December 16, 2021, 03:15:04 pm

Quote from: John44 – December 16, 2021, 01:34:07 pm

Brett,maybe revise the statement to no way to charge while not running.

Correct. Addressing the topic of use of the boost switch "The night before starting".

As you said, the engine-driven alternator charges both battery banks when the engine is running.

Re: Boost switch

Reply #29 – December 16, 2021, 03:24:26 pm

Quote from: wolfe10 – December 16, 2021, 11:45:11 am

Actually, as Foretravel built the coaches, there is NO means of charging the chassis batteries.

It would not surprise me for someone at Foretravel to suggest leaving the boost switch on that long when you are on shore power so that the converter or inverter/charger will charge up the chassis batteries.

Are there other means (many better) for charging the chassis batteries? Sure.

I was having a discussion with a guy on Facebook about leaving the boost on all the time to keep start batteries charged. He produced this from Foretravel.
Said he has kept the boost switch on for years with no issues.
Keith

Re: Boost switch

Reply #30 – December 16, 2021, 03:29:48 pm

While the boost switch CAN be used to charge the chassis batteries, it is not what I would call "the preferred method".

If shore power goes down, BOTH battery banks discharge. Now, neither engine nor generator can be started.

I much prefer to see either a "smart thief" like the Xantrex Echo charger OR a good quality small-output smart charged specifically/only for the chassis batteries.

Re: Boost switch

Reply #31 – December 16, 2021, 04:09:11 pm

Quote from: wolfe10 – December 16, 2021, 03:29:48 pm

While the boost switch CAN be used to charge the chassis batteries, it is not what I would call "the preferred method".

If shore power goes down, BOTH battery banks discharge. Now, neither engine nor generator can be started.

I much prefer to see either a "smart thief" like the Xantrex Echo charger OR a good quality small-output smart charged specifically/only for the chassis batteries.

That's exactly what I told him from info learned here.

Keith

Re: Boost switch

Reply #32 – December 16, 2021, 06:03:11 pm

Potential problems I see with boost switch on all the time or for long periods,you go out 24 hours before a trip and turn it on,your
2 house batteries are fully charged from the inverter/charger,now your charging the 2 house batteries that are already fully charged.If your start battery is a AGM you should be using a charger that is designed for AGM batteries for optimum life.Plus all the things Brett thought of.

Re: Boost switch

Reply #33 – December 16, 2021, 07:04:15 pm

Quote from: John44 – December 16, 2021, 06:03:11 pm

Potential problems I see with boost switch on all the time or for long periods,you go out 24 hours before a trip and turn it on,your
2 house batteries are fully charged from the inverter/charger,now your charging the 2 house batteries that are already fully charged.If your start battery is a AGM you should be using a charger that is designed for AGM batteries for optimum life.Plus all the things Brett thought of.

Using a PowerMax and now a Progressive Dynamics converter, our AGMs house batteries are 13 years old with no issues and no special settings. Our jumper keeps the engine batteries up at the same time.

Pierce

Re: Boost switch

Reply #34 – December 16, 2021, 07:31:03 pm

Quote from: Pierce & Gaylie Stewart – December 16, 2021, 07:04:15 pm

...our AGMs house batteries are 13 years old with no issues and no special settings...

Wow, that's impressive. At 5 years our Gels have approx 80% of original AHs. What % of original capacity do you think you have at 13 years?

Re: Boost switch

Reply #35 – December 16, 2021, 08:19:15 pm

Quote

That's exactly what I told him from info learned here.
Keith

Wyatt Sabourin. I can hear you laughing.

Re: Boost switch

Reply #36 – December 16, 2021, 08:20:01 pm

Slight but similar topic, I have been meaning to post this. How would one test their boost switch is working ? I searched and one said to put in a digital volt reader in the cig lighter and see if there is a jump when the switch is on. I tried both cig lighters and the voltage did not change.

Re: Boost switch

Reply #37 – December 16, 2021, 08:40:15 pm

I use a 10 amp draw test light take the cables off one side, turn the boost on and
put the test light on the lug that I removed the cable from and if light comes on
the boost works.

Re: Boost switch

Reply #38 – December 16, 2021, 08:45:37 pm

Quote from: Jason – December 16, 2021, 08:20:01 pm

Slight but similar topic, I have been meaning to post this. How would one test their boost switch is working ? I searched and one said to put in a digital volt reader in the cig lighter and see if there is a jump when the switch is on. I tried both cig lighters and the voltage did not change.

My starter turns over faster if I use the boost.

Keith

Re: Boost switch

Reply #39 – December 16, 2021, 09:09:23 pm

Quote from: hdff – December 16, 2021, 08:45:37 pm

My starter turns over faster if I use the boost.
Keith

If it does, you have a fault in the batteries, terminals, cables or starter. I've tried ours on both and there is zero difference. If you have more CCAs than the Cummins CCA recommendation for your engine, something is wrong. Check cranking voltage.

Pierce

Re: Boost switch

Reply #40 – August 26, 2024, 01:12:18 pm

Quote from: Chuck & Jeannie – December 14, 2021, 09:40:20 pm

And actually, in my case, the boost solenoid is not exactly the same as the ignition solenoid. I use a Blue Sea 9012 for ignition duties, and a Blue Sea 7701ML as a boost solenoid. The 7701ML draws no current in "ON" or "OFF" state, only draws current when changing state of switch. I COULD (if I so desired) leave it turned on for months at a time with no worries (about heat buildup or current draw).

Solenoid L-Series - 250A 12/24V - Blue Sea Systems

ML Solenoid - 12V DC - Blue Sea Systems

Bumping this (can you tell we're collecting spares/zero-ing out the new coach?

)

Would this still be the recommendation today?

Re: Boost switch

Reply #41 – August 26, 2024, 02:01:50 pm

Quote from: Michelle – August 26, 2024, 01:12:18 pm

Bumping this (can you tell we're collecting spares/zero-ing out the new coach? )

Would this still be the recommendation today?

Not the original poster that shared this but I would recommend these. I had gone through a number of relays in trying to do a battery disconnect on my Tahoe. Finally got he Blue Sea 7701 and it has lasted. The problem I see in using the 7701 for battery boost is existing wiring. In order for this switch to work you need at least 3 wires to the unit. 1 ground, 1 with 12v momentary for on, and 1 momentary for off.

I am getting the Blue Sea 9012 for my HWH power solenoid for the hydraulic pump. I had to replace the HWH ones about 6 years ago with new HWH ones. They are starting to act up again so figured I would get better solenoid this time around.

Re: Boost switch

Reply #42 – August 26, 2024, 02:07:01 pm

Quote from: Jason – December 16, 2021, 08:20:01 pm

Slight but similar topic, I have been meaning to post this. How would one test their boost switch is working ? I searched and one said to put in a digital volt reader in the cig lighter and see if there is a jump when the switch is on. I tried both cig lighters and the voltage did not change.

What were your voltage readings? If plugged in to shore power with the charger on you should be in the 13+ voltage range. With no charger on your chassis batteries you should be in the 12.5-12.7 range. If both are in the 13+ range before starting there is a good possibly that your chassis batteries have a charger on them, or your boost switch is stuck closed (connected)

Re: Boost switch

Reply #43 – August 26, 2024, 04:02:59 pm

Quote from: Michelle – August 26, 2024, 01:12:18 pm

Would this still be the recommendation today?

Yes - I would still recommend this combination. As Turbojack states in Reply #41 (above) the 7701 does require some additional wiring. Nothing that can't be accomplished with a little basic ingenuity. I detailed the installation of my 7701 in the initial post in the thread linked below:

'93 U280 Isolator Panel Upgrade

Re: Boost switch

Reply #44 – August 26, 2024, 05:51:58 pm

If putting in the blue sea 7701 you can get rid of the isolator and use the existing cables and both
sets of batteries will charge from either alternator or the inverter charger.

Re: Boost switch

Reply #45 – August 26, 2024, 11:44:23 pm

My experience is that any manual way to charge the chassis batteries will finally be forgotten or fail.

Finally went the full route like the new coaches have and put in a blue seas ACR 500 amp magnetic switching relay

Factory boost takes 3amps to keep it connected.

My guru buddy connected the optional starter lug wire from the starter relay to the ACR so that the batteries do not auto connect when starting unless selected to connect. He had a customers coach chassis batteries failing that were being covered up by the auto connect. Did not know they were failing as using both banks covered that up. Pretty smart of Blue-Seas to have that lug on their ACR so you can select to have the starter only use the chassis batteries to start.

The more involved part for me as I have no power in storage was to add a 1100 watt solar system and a PT100 Magnum energy solar controller. Other than corroded battery terminals for sure everything is charged correctly as the Battery Temp system adjusts the solar system charging voltage to the batteries based on their exact temp.

Turns out the pt100 cycles the batteries less in storage than the inverter would have if on shore power as the inverter lets the batteries run down then recharges them. The magnum RC lets them go down 10%? The Magnum ARC I think can be set to let them run down 5% if memory serves me.

Expensive but in my area, in shaky town, a for sure fully charged coach maybe a real necessity. No way out of my area if a disaster occurs. 3 freeway lanes and 30 million people.

Re: Boost switch

Reply #46 – August 27, 2024, 02:18:08 pm

the Blue Sea 7701 is automatic and can be done manually.

Re: Boost switch

Reply #47 – August 27, 2024, 02:38:32 pm

Quote from: oldguy – August 27, 2024, 02:18:08 pm

the Blue Sea 7701 is automatic and can be done manually.

Sorry, but the Blue Sea 7701 ML is not automatic - it is a manual control latching solenoid only.

ML Solenoid - 12V DC - Blue Sea Systems

The Blue Sea 7620 ML-ACR Automatic Charging Relay looks very similar and IS automatic. This may be the ACR to which Bob refers.

ML-ACR Automatic Charging Relay - 12V DC 500A - Blue Sea Systems

Re: Boost switch

Reply #48 – August 27, 2024, 08:45:47 pm

Thanks Chuck it's the ML-ACR Automatic Charging Relay - 12V DC 500A - Blue Sea Systems that I
have.

Re: Boost switch

Reply #49 – August 28, 2024, 02:50:56 am

As i posted under charge from any source to either battery banks the ML-ACR will remain combined while starting unless you run na sense wire from the starter relay to the dedicated lug on the ML-ARC which then uncombines the battery banks.

Under no charging and with any discharge occurring for a short period of time the combiner auto disconnects the banks so starting would only use the chassis batteries anyway

We elected to not run an additional wire from the ML-ARC to the front selector switch to light up when the batteries are combined.

I my case i have two led battery voltage led readouts installed in the dash battery voltage cigarette plugs. Not as fast indicating connect/disconnect as the switches led indication but running the wire would have been to much time and effort consuming.

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