DVSR help...

[lazergeek]

I think I found a simi easy solution that would engange with either or both motors were running. https://www.amazon.com/Dual-SPST-NO-Power-Relay-Module/dp/B09T6TNRMV/ Connect 1 relay input to each ignition switch, Parallel the 2 red outputs and connect to a battery source voltage and parallel the negtives adn connect to the cut wire on the DVSR.

 

[FSH 210 Sport]

I think that would work Laze…

Here is how I see your wring?

Input 1 yellow to the boat ignition 1/port, input 1 blue wire to ground
Input 2 yellow to the boat ignition 2/ starboard, input 2 blue wire to ground

Output C1 red & Output C2 red tie together and attach to switched side of start battery.
Output NO1 black & Output NO2 black tie together and attach to DVSR red wire.



I get having the two relays in one box. How about using two of these as they are waterproof relays.

Amazon.com

Yes, using the rocker switch on the dash is a very simple way to turn the DVSR on and off, essentially the same as using an ignition hot to activate a relay. The other thing I do is I wait for the starter battery voltage to exceed the house battery voltage before I activate the rocker switch, I do that to keep the house battery from trying to flow it’s power into the start battery.

If you put a smart shunt (sorry can’t remember if you did that already) on your house battery you will be surprised how many amps flow into your LiFePO4 battery when it’s down 40-50% from your engines.

 

[lazergeek]

I think that would work Laze…

Here is how I see your wring?

Input 1 yellow to the boat ignition 1/port, input 1 blue wire to ground
Input 2 yellow to the boat ignition 2/ starboard, input 2 blue wire to ground

Output C1 red & Output C2 red tie together and attach to switched side of start battery.
Output NO1 black & Output NO2 black tie together and attach to DVSR red wire.

View attachment 213132

I get having the two relays in one box. How about using two of these as they are waterproof relays.

Amazon.com

Yes, using the rocker switch on the dash is a very simple way to turn the DVSR on and off, essentially the same as using an ignition hot to activate a relay. The other thing I do is I wait for the starter battery voltage to exceed the house battery voltage before I activate the rocker switch, I do that to keep the house battery from trying to flow it’s power into the start battery.

If you put a smart shunt (sorry can’t remember if you did that already) on your house battery you will be surprised how many amps flow into your LiFePO4 battery when it’s down 40-50% from your engines.

Your wireing explination was exactly what i was thinking too. I was also looking at the single relays I just posed the one I did for easier explination to everyone here.. I did put a shunt in last year, although I usually dont look at the app while running the boat, usully while just floating to see how much solar I have coming in. Im also switching my solar charge controleler to a 2 bank unit. My last 2 outings the low voltage alarm has been going off on my VHF for the house battery after just sitting 10 min so that battery was due for replacing anyway.

 

[FSH 210 Sport]

Your wireing explination was exactly what i was thinking too. I was also looking at the single relays I just posed the one I did for easier explination to everyone here.. I did put a shunt in last year, although I usually dont look at the app while running the boat, usully while just floating to see how much solar I have coming in. Im also switching my solar charge controleler to a 2 bank unit. My last 2 outings the low voltage alarm has been going off on my VHF for the house battery after just sitting 10 min so that battery was due for replacing anyway.

Right on…

The most charge current I’ve seen going into my Li house battery via the smart shunt was 26A, that was the first test I did with the boat parked in front of the shop with nothing else turned on at 3500 rpm on each engine. While on the water if I let the battery go to say an 80% state of charge or lower I see roughly 21-23 A coming in. I did not have the shunt installed when I still had a flooded lead acid house battery for comparison, but I’d like to think based on my research that the Li battery is taking in more amps due to its low resistance.

Do you have your shunt set up to monitor your start battery voltage? I find that the shunt battery voltage readings are .4-.5 volts higher than the connext screen battery voltages, is that your experience as well?

The two bank solar charge controller you are going to install, one will be tuned for the start flooded acid battery and the other tuned for the Li house battery?

 

[lazergeek]

Right on…

The most charge current I’ve seen going into my Li house battery via the smart shunt was 26A, that was the first test I did with the boat parked in front of the shop with nothing else turned on at 3500 rpm on each engine. While on the water if I let the battery go to say an 80% state of charge or lower I see roughly 21-23 A coming in. I did not have the shunt installed when I still had a flooded lead acid house battery for comparison, but I’d like to think based on my research that the Li battery is taking in more amps due to its low resistance.

Do you have your shunt set up to monitor your start battery voltage? I find that the shunt battery voltage readings are .4-.5 volts higher than the connext screen battery voltages, is that your experience as well?

The two bank solar charge controller you are going to install, one will be tuned for the start flooded acid battery and the other tuned for the Li house battery?

I just have a single shunt on the house battery. Yes I see the voltage drop to the connext too. The 2 bank solar charge controller has battery selection for bank 1 which will be set to Lifepo4 profile Lithium house batter and bank 2 only has FLA profile 1amp trickle charger which should be fine.

 

[Adrian @ JB Solutions]

My DSVR stopped working. House battery only charges when yellow switch is flipped to both. Any ideas how to by pass?

 

[lazergeek]

My DSVR stopped working. House battery only charges when yellow switch is flipped to both. Any ideas how to by pass?

Make sure the black wire from the DVSR is connected to the battery grounds and make sure the red wire on the back is not cut.

 

[lazergeek]

Your wireing explination was exactly what i was thinking too. I was also looking at the single relays I just posed the one I did for easier explination to everyone here.. I did put a shunt in last year, although I usually dont look at the app while running the boat, usully while just floating to see how much solar I have coming in. Im also switching my solar charge controleler to a 2 bank unit. My last 2 outings the low voltage alarm has been going off on my VHF for the house battery after just sitting 10 min so that battery was due for replacing anyway.

I Installed my new solar charge controller and ignituon relays to control the DVSR today. I forgot my boat keys so couldn't actually test it but "should" work if manual wiring diagram was correct.

 

[jcb1977]

I confirmed today this solution does work....just change the posts at each battery switch to deactivate the DVSR when battery switches are off to independently charge each battery. This is in lieu of a switch on the DVSR ground or snipping the red loop wire. I think a little easier to do.

 

[FSH 210 Sport]

I confirmed today this solution does work....just change the posts at each battery switch to deactivate the DVSR when battery switches are off to independently charge each battery. This is in lieu of a switch on the DVSR ground or snipping the red loop wire. I think a little easier to do.View attachment 218946

So you are saying to swap the line and load sides?

 

[jcb1977]

So you are saying to swap the line and load sides?

yes.....at each battery switch change the DVSR positives from the Battery post to the Load Post (green arrows in diagram). With the battery switches off, it deactivates the DVSR so no small draw from batteries with switches off, and can charge individually.

 

[FSH 210 Sport]

yes.....at each battery switch change the DVSR positives from the Battery post to the Load Post (green arrows in diagram). With the battery switches off, it deactivates the DVSR so no small draw from batteries with switches off, and can charge individually.

That is a great find! Thanks for posting that!!

 

[Whiplash22]

Alright, I have another one for the Guru’s here. Looking to add a Lifepo4 battery for the house battery, which everything here explains what I need to do. My caveat is I have a 36v trolling motor battery with a monster lithium quantum charger that charges the trolling battery off the crank battery both on shore power and from the stator. Will I have any issues with the dvsr trying to balance each battery while the engines are on as it is going to see a draw from the cranking battery? Has anyone removed the DVSR entirely? If I remove it will it cause any unforeseen issues aside from convenience? I will still retain all manual switches and cutoffs.

 

[FSH 210 Sport]

This is a good question!

Please tell me about the 12V to 36V DC to DC charger you have as that set up is alluring to me as well.

Okay, charging, charging only occurs due to potential difference in voltage, in other words the charging source voltage has to be higher than the battery being charged to get the electrons to flow that direction, or there is more electrons on the charging side than the being charged side. Make sense?

In your current configuration, when you have the engines running, does the dvsr close and try to charge the house battery while the start battery is being charged and charging the trolling motor battery? If so, what is the connext battery voltage reading?

Since the resting voltage of a LFP house or start battery is 13.6 volts when it is fully charged, that will activate the dvsr since its close point is 13.4 volts, (opens at 12.7 which is when a LFP battery is almost fully depleted) when that happens, the proposed LFP house battery could very well start “charging“ the trolling motor battery bank until such time that A-the LFP house battery voltage drops enough due to charging the trolling motor battery-that whole potential difference thing, or B-IF the alternators are supplying high enough voltage to keep the electron flow INTO the house battery at some level with the dvsr closed.

The alternators on our boats only produce roughly 13 amps each, maybe 14, but the point is, there is not a lot of left over charging power, their full output is at 3500 rpm’s, the most I have ever seen on my boat was 26 amps flowing into my LFP house battery but dropped off relatively quickly as the battery voltage climbed as the battery was being charged. That being said, the rectifier / regulators which convert the three phase AC voltage from out alternators to DC and then regulate the voltage to 14.4 volts by shunting the excess voltage to ground when it is unneeded will charge aggressively with the addition of a lot of load which drops the voltage. Don’t worry you will not over burden the alternators, the alternators in our boats are always at full output since their magnetic fields are fixed, they are known as PMA’s or permanent magnet alternators which are different from automotive style alternators which regulate the output by altering the current flow into the rotor or magnetic field on the rotor, these types of alternators can be easily damaged by LFP batteries unless there are protections there, either thermal within the alternator or just current limiting.

In my opinion, you need to set your dvsr activation up on a rocker switch on the dash so that you can control when it closes. Also, you need to put in a couple of victron smart shunts so you can monitor the amperage flow into or out of the trolling motor battery bank on the load side of the DC to DC charger, and another one on the house battery so you KNOW what is going on

That DC to DC charger is going to be looking for enough voltage to operate, and it should have a charge relay, dvsr / ACR itself so that once the proper input voltage is present it will close and begin charging, voltage too low and it will not operate. That is why I asked above whether or not the dvsr is currently operating and what the connext screen voltages are. To be clear, there should be no flow from the trolling battery bank back through the DC to DC charger due to the step up transformers and diodes, as well as its internal acr.

Should you disconnect the dvsr ? NO.

But you will need to have more control over it on the dash so that once voltages look good you can activate it and let the engines charge the house battery too. Simply hooking the dvsr up to a run hot will not work in your case as you need to make sure the power flows are correct so that you are not draining your house battery to charge the trolling motor battery bank via the DC to DC charger.

Does all that make sense?

 

[Whiplash22]

So I have only started the boat on the trailer with the current set up, the weather has not been conducive for boating here in Oklahoma. When started the connext shows the static voltage of 12.7 at start which increases to 13.6, and then tapers back down to 12.7. This dip indicates to me that the dc to dc charger is now pulling voltage from the cranking battery and transferring it to the trolling motor battery. How that thing works is beyond my level of electrical knowledge and expertise, magic blue smoke I imagine. So to me, this means if I remove the DVSR the “alternators” will charge each battery respectively and mixing battery chemistries won’t be an issue if and when they are bridged.

 

[FSH 210 Sport]

So I have only started the boat on the trailer with the current set up, the weather has not been conducive for boating here in Oklahoma. When started the connext shows the static voltage of 12.7 at start which increases to 13.6, and then tapers back down to 12.7. This dip indicates to me that the dc to dc charger is now pulling voltage from the cranking battery and transferring it to the trolling motor battery. How that thing works is beyond my level of electrical knowledge and expertise, magic blue smoke I imagine. So to me, this means if I remove the DVSR the “alternators” will charge each battery respectively and mixing battery chemistries won’t be an issue if and when they are bridged.

If you remove the dvsr your house battery will not charge off of the alternators. I’m assuming you have a two bank on board charger?

That tapering down of voltage you saw could very well be the DVSR closing and charging the house battery?

I looked up the DC to DC charger you listed,

https://www.monstermarinelithium.com/collections/chargers/products/12v-to-36v-quantum-charge-on-the-run

I have a call into them as the pick up voltage is listed as “a certain voltage”… not specific enough for me, I’d want to know the exact pick up voltage. It lists the amperage output as 10A maximum @43.8 volts or 438 watts. At 26 amps and 14.4 volts coming from the engines alternators that’s 374.4 watts, but hard to say if the output will stay that high. So if you use the formula Is (amps secondary) = Watts / Es or secondary voltage, then, Is is = 374.4 W / 43.8 Es=8.54 Amps going into the trolling motor bank. Not a lot but it will still put some Ah’s / KWh’s back into the trolling motor bank. What size onboard charger do you have ?

 

[FSH 210 Sport]

I heard back from them, lead acid / AGM pick up voltage is 13.5volts, and the lithium pick up is 14 volts…just realized I should have asked for the drop out voltages darn it. I’ll have to call back next week.

I think having the DVSR and the monster marine charger, each with its own switch would be best, this way you could use the limited amp output of the engines alternators to focus on charging either the house battery or the trolling motor bank once the start battery has come up to full charge.

And I have to wonder what the drop out voltage is on the monster marine charger is, and whether or not it will be high enough to stay engaged once it starts charging the trolling motor batteries and the bus voltage of the engines alternators drops due to that charging load. You may need to let the start battery come up to 14.4 volts, finish its charge, before letting the monster marine charger do it’s thing to keep the alternator buss voltage as high as possible, otherwise it may start cycling on and off.

 

[Whiplash22]

Yea I have a triple bank Noco 10 amp. Currently have 2 banks utilized one for crank and one for the house. I plan to have two 100 ah mini lifepo4 set up for the house batteries. I was assuming that both house and cranking batteries each had their own direct feed from the alternators. Which would make sense, if the DVSR is integral to charging the house battery then how would I wire up the switch and control mechanism as you all have described.

 

[FSH 210 Sport]

Both alternators go to the start battery, this assures the start battery gets charged first and is therefore always fully charged, well mostly, before the house battery starts getting a charge.

The DVSR closes at 13.4 volts to allow charging of the house battery, the DVSR opens at 12.7 which isolates the start and house batteries, again preserving the start battery for starting duties only. Due to the fact the LFP batteries have a resting voltage of 13.6 is why the DVSR must not be active when the engines are off, otherwise the LFP batteries will discharge into the lower voltage of the lead acid start battery.

On the back of the DVSR module there is a red wire where you can make changes to how the DVSR operates per BEP Marine.

You can read about it here:

https://www.bepmarine.com/-/media/inriver/710-140A_INSTR_BEP.pdf?modified=20230328095440

This is how mine is set up in the “storage mode”.



You can also set it up as a “run” hot so that it only operates when the engines are running. BUT in your situation I think it best to be able to isolate charging the house bank or the trolling motor bank.

I just ran a wire up to the dash for the feed to the DVSR and switched it via a rocker switch so I have control over it, in my case I wait until the start battery voltage gets above the house battery voltage before I activate the DVSR, usually I wat until the start battery reaches 14 volts.

 

[Whiplash22]

Is that a two way or 3 way rocker switch?