Bringing 1997 electrics up to date

[CanuckRV]

We bought a 1997 Roadtrek Popular last spring I took care of some bodywork, and installed a 185 amp-hour AGM battery as the old one was shot and the battery compartment under the floor was rotting away.
I have since installed a Renogy 40 amp DC-DC charger removed the old converter and installed a Noco Genius 2 battery charger instead, for AC power I have a 3000w pure sine wave inverter (yes I know its overkill).
On a slow boat from China, I have a DVB01 to control the DC-DC, which I will install.
We had some issues with our alternator last summer while parked with the AC on so I'm hoping the DVB01 will help with that. I would like to set the parameters for the DVB01 to come on after the alternator running for 90 seconds and putting out at least 13v and turn off if it goes below 12.5v does this seem right?

Also with the DC-DC do I still need the isolator?

I would also like to change the battery to Lithium in the near future and am toying around with the idea of getting a suitcase solar charger, my only issue with that is we tend to be moving all the time so not sure how much time we would be stationary to use it and if were do stay someplace for any length of time we are usually out of the campsite and I don't want it to walk away.

Am I on the right track with my thinking? sorry really rambling but trying to do it right once.
Thanks
Jerome

[markopolo]

Originally Posted by CanuckRV

.................. I would like to set the parameters for the DVB01 to come on after the alternator running for 90 seconds and putting out at least 13v and turn off if it goes below 12.5v does this seem right?

Also with the DC-DC do I still need the isolator? ........................

When turned on, the Renogy DC-DC draws from the chassis battery. If using a DVB01 to turn the Renogy on, I'd suggest using a higher turn off voltage such as 12.8V so as to always leave the chassis battery at a high state of charge.

I think forum member ReilyM ended up using Function 3 on the DVB01 set with On at 13.2V and Off at 12.8V.

An isolator is not needed when using a DC-DC unit.

[CanuckRV]

So I got a message this morning from Amazon that my shipment was going to be delayed until December but when I checked the mail today there they were (i got two just in case)

However, the one I got does not look like the one in the user manual posted to the forum earlier. there are only 3 lugs to connect the power wires to not the 4 shown in the manual. Will this one work for me?
https://ibb.co/rMKzj3n

[markopolo]

That appears to be a FRM01 timer relay module -> https://content.instructables.com/OR...7DIUHMS1GV.pdf <- with no voltage triggers.

[CanuckRV]

Oh for Pete's sake!!!

[CanuckRV]

Well, I got a reply from the dealer for the DVB01 it looks like it will be another month before I have it if they send the right part. They say they are sending airmail I guess their planes are slower than what we have.

If I move the cable to the house battery to the same lug on the isolator as the alternator cable would the cassie battery still be isolated? the reason I ask is that I use the power from the alternator to turn the DC-DC on with the D+ wire. If the Cassie battery is not still isolated there would be power and the DC-DC would always be on until the voltage dropped.

[markopolo]

If you move the house battery lug to the same post as the alternator on a diode type isolator then the house battery would be expected to drain into the chassis battery & related chassis parasitic loads.

Both cables (house & chassis) would be +12V at all times because they are attached to batteries so either would keep the Renogy turned on if tapped into for the D+ connection. Some folks just use a switch with +12v on the D+ connection and manually turn the Renogy on and off. The risk is that you have to remember to turn it on and also to turn it off.

Looks like there are two DVB01's on Amazon.ca with Prime shipping so delivery available in just days if you have a Prime account.

[CanuckRV]

I think for now I will leave the isolator as is because it is working for me. How much of a gain (Electric wise) would it be to remove it?
The replacement DVB01's have been shipped airmail so should be here shortly, unfortunately, the weather has turned so it may become a spring project.

[CanuckRV]

Was just shopping on the Canadian Renogy site they have a 100ah lithium for $670 but they also have a 170ah for $950 which for the price difference seems to be the way to go as I was thinking of 2 100ah the 170 would give me plenty of power at a smaller size. I really don't have huge power needs.

[HarryN]

Depending on if you like to run things on the edge or more conservatively, it might makes sense to bring your design up to a 4 battery implementation.

For the typical ~ size 24 / 27 / 31 battery, regardless of LiFe or AGM, they really are designed to operate at ~ 600 watts discharge rates per battery and be "stable".

A person can make an arguments that might get you to 1 kW per battery but that is a real stretch IMHO.

It isn't about total capacity, it is about ability to deliver power. Sort of a crude analogy to how big is the fuel tank vs fuel pump. At some point, it might take more than one to feed a large engine.

The inverter might be larger than your needs, but even if you are only using 1500 watts of it, adding more batteries might be a great benefit than changing types.

[markopolo]

Originally Posted by CanuckRV

Was just shopping on the Canadian Renogy site they have a 100ah lithium for $670 but they also have a 170ah for $950 which for the price difference seems to be the way to go as I was thinking of 2 100ah the 170 would give me plenty of power at a smaller size. I really don't have huge power needs.

They're very different batteries. Maybe think of the 170Ah as 1st Generation from Renogy and the 100Ah on offer as 2nd Generation from Renogy.

Both are limited to max 100A discharge. The 100Ah is rated 4000 cycles and the 170Ah is rated 2000 cycles. The 100Ah has 16 pouch cells inside and the 170Ah has 212 cylindrical cells inside.

2 x the 100Ah in parallel give the possibility of 200A max discharge power capability and 200Ah power capacity.

[CanuckRV]

Thanks for the explanation it helps

[CanuckRV]

Well according to the tracking the DVB01 is sitting at the post office since Sunday hopefully it get delivered soon.

[CanuckRV]

Well they sent the exact same thing I would think Amazon would screen their sellers better. Don't order anything through Amazon from bbrhmc73jhpu yes that's the name of the company.

[CanuckRV]

Well the DVB01's are still in shipping but the good news is I ordered two 100ah LiFePO4 from Renogy they should be here next week.

[CanuckRV]

Yahoo the DVB01 have arrived. I have some wiring questions to connect it to the Renorgy 40amp DC DC charger. Right now the wire goes from the DC+ ignition terminal to the supply wire from the alternator through the isolator. I take it this now goes to the DC+ on the dvb01 and I run a wire to ground to the DC-.and run a wire from the NO to the DC DC charger. do I need to run a wire from the com to ground?
I can wire a house but electronic circuits are not my forte.
thanks for all the help.

[markopolo]

If I recall this correctly then NC, COM & NO don't connect to DC-, DC+, V- & V+ through the relay. NC, COM & NO can even be used for AC loads.

dvb01 supply.jpg

Mike's manual:
https://www.classbforum.com/forums/f...tml#post122181


With a large power supply such as an alternator, DC+, V+ & COM can share that source. That's how Mike did it:

Originally Posted by reilym

............................. In the RV, I'll use the alternator feed into the DC-DC for DC+, V+ and COM......................

NO would go to D+ on the Renogy to turn it on when the programed parameters of the DVB01 are met.

DC-, V- and the Renogy unit's Negative DC Input would share the same ground.

This topic -> https://www.classbforum.com/forums/f...way-11572.html <- is worth reading through for ideas.

[CanuckRV]

Thanks for the links. I have read that thread many times and have the manual, but still have questions on the wiring.
1 If I run a wire from the positive feed from the alternator to DC+ can I use a Jumper from DC+ to V+ and the same for the ground to DC- V-?
2 the Renorgy DC DC only uses one wire to the to the DC+ ignition terminal do I run a wire from NO to that? Do I need a com wire to somewhere?
is this sketch correct? https://ibb.co/yFRMBLm

[markopolo]

Let's use Mike's programing example from his manual. That is to turn the Renogy on if the voltage from the chassis battery/alternator is greater than 13.2V and turn it off if the voltage is less than 12.8V.

For wiring that, the DVB01's "DC+", "V+" & "COM" would all share the same chassis battery/alternator positive power source. The DVB01's "NO" would go to the Renogy's "D+" to turn it on when the programed parameters of the DVB01 are met.

For your question #1 - Yes, but also feed "COM" with a + jumper wire. And yes, all grounds (negative) will be shared from chassis side.

For your question #2 - Yes, The DVB01's "NO" would go to the Renogy's "D+" to turn it on. "COM" is explained above. Your sketch is missing the "COM" + feed wire.

DVB01 "V+" & "V-" will be measuring the chassis battery/alternator voltage.

DVB01 "DC+" & "DC-" power the DVB01.

DVB01 "COM" needs power. In this example it's +12V from the chassis battery/alternator side.

DVB01 "NO" gets connected to the Renogy's "D+".

Some additional thoughts:

If you're using the isolator center post and haven't moved any other isolator wires for this then I'd expect the DVB01 to shut down when the engine is not running. (I'm not 100% sure of that - maybe some voltage leaks back through the diodes)

Using the isolator center post (without movings any other isolator wires) would complicate things on my van because the voltage is high at the center post. It measures 15.25V at the center post and 14.5V outer posts on mine on a cool alternator with already fully charged batteries. It's high because there's a voltage sense wire from the alternator on one of the isolator's outer battery posts. It might all work out if I increased the DVB01 setpoints by 0.75V. That would be 13.95V turn on and 13.55V turn off if following the example in Mike's manual.

I don't know if your van has an alternator voltage sense wire like mine.

[CanuckRV]

thanks so i can jumper the the DC+ to the com and I'm good to go?