Concerns converting to lithium

[LibertyCall]

After thoroughly exhausting two sets of Trojan SLA house batteries, I'm seriously considering going lithium. I'm told the best way to save my alternator is with a DC-DC charger. My concern is the mass of wires, isolator, BIRD, etc. Not sure if they will remain necessary but the quantity of wires tells me they will. It's a 2002 Mountain Aire DP. Here's a pics of the hornet's nest.

[twinboat]

Disable the big relay by removing the wires on the BIRD. Mark and tape them up for when you trade it in. Hook things back up and keep your batteries and charger for the next RV.

Now you can use the 2 large terminals of the same solenoid to connect your battery to battery charger. Leave what's on there and add wires to the charger. Looks like the large black looping wire is the house battery. The other large red cable will be the chassis battery.

If your batt to batt charger needs an ignition source, use the one from the BIRD.

Lots of spark potential there so disconnect the shore power and battery cables before diving in.

The smaller solenoid is your house battery disconnect, don't touch that.

Once you do that, you'll need a lithium Amp L Start to keep your chassis battery charged while on shore power. The BIRD used to handle that but it's not lithium compatible.

[LibertyCall]

Originally Posted by twinboat

Disable the big relay by removing the wires on the BIRD. Mark and tape them up for when you trade it in. Hook things back up and keep your batteries and charger for the next RV.

Now you can use the 2 large terminals of the same solenoid to connect your battery to battery charger. Leave what's on there and add wires to the charger. Looks like the large black looping wire is the house battery. The other large red cable will be the chassis battery.

If your batt to batt charger needs an ignition source, use the one from the BIRD.

Lots of spark potential there so disconnect the shore power and battery cables before diving in.

The smaller solenoid is your house battery disconnect, don't touch that.

Once you do that, you'll need a lithium Amp L Start to keep your chassis battery charged while on shore power. The BIRD used to handle that but it's not lithium compatible.

That was about enough fear factor to make me go AGM and leave everything else the same. I’ll keep your email in my back pocket. Thank you for the info.

[creativepart]

I did this project last April. I can tell you two things:

1. Looking at the wiring and all those solenoids looked super scary and really confusing. But after I started the project it actually turned out to be very logical and surprisingly straightforward.

2. The lithium batteries are really game changers. Very little storage discharge, very quick charging and consistent power at the ready.

The one thing I quickly learned was the need to maintain the chassis battery when not traveling. Traveling, the alternator keeps the chassis battery topped up. But, sitting in storage or on shore power in a campsite you need to add some way to maintain that charge. I added an “Amp-L-Start” to the mix of wires right there - which was super easy after learning the wiring from doing the install - and this fixed that problem for about $100.

[LibertyCall]

Thank you for the reply. That makes two replies with the Amp-L-Start comment. In all the YouTube install videos I've watched I've not seen that mentioned. What would I be doing that would require that? I have a Xantrex SW-3012 inverter/charger that has been taking care of that. I might sound clueless and amateurish but I was a Navy electronics tech for radar and communications gear. Not much experience with automotive and don't have a wiring diagram of the coach. I thought this was primarily tapping the alternator charge wire that goes to the chassis batteries and running it to the DC-DC charger and over to the house batteries.

I truly appreciate the help.

[LibertyCall]

Not sure which is exactly the smaller one. Would that be the Intellitec or the White-Rodgers device?

[creativepart]

Originally Posted by LibertyCall

Thank you for the reply. That makes two replies with the Amp-L-Start comment. In all the YouTube install videos I've watched I've not seen that mentioned. What would I be doing that would require that?

You'll be eliminating the OEM connection between the Chassis and House batteries.

Currently, your White Rogers solenoid connects the two battery banks when you are driving. This charges both the Chassis and House banks via the alternator. Then when parked and on shore power the solenoid connects the chassis bank to the house bank whenever the house batteries are near fully charged and the chassis battery starts dropping in voltage (usually around 12.5v) to keep the chassis battery fully charged.

Since you don't want your alternator charging your LiPo batteries you are removing the connection between the two banks.

Your DC2DC charger will take the place of the alternator charging the House bank while you are driving. While, of course, the alternator will still be charging the Chassis bank.

Then when you arrive at a campground for an extended stay and are plugged into shore power, your inverter charger keeps the House bank fully charged. But what about that Chassis bank? What's keeping that fully charged?

This is where the Amp-L-Start comes in. You simply connect it between the House and Chassis banks, using the same wiring that was already there for the White Rogers BIM setup. This little box does the same job as your original solenoid to connect the two banks, as necessary, when you are on shore power (not while driving). This keeps your Chassis bank from gradually losing power from parasitic draws while parked on shore power. When the House bank is near fully charged the Amp-L-Start "steals" a little power from that bank to trickle charge the Chassis bank and keep it charged up.

When I did my install, I figured it would take a good while for the Chassis bank to need any charging. So, I didn't plan on using the Amp-L-Start at all. But I was wrong. With the RV sitting in my driveway, on shore power, as I finished all my installations I could see the Chassis battery dropping in voltage every day or two. So, I ordered one and the installation took less than an hour. Right away it started charging the Chassis battery and all was fine from them on.

[twinboat]

Originally Posted by LibertyCall

Not sure which is exactly the smaller one. Would that be the Intellitec or the White-Rodgers device?

Intellitc is the smaller battery disconnect solenoid. You can see that it only has a large cable on one large terminal. The lower amp house loads are on the other side.

Charging between the batteries are done with the White Rodgers solenoid.

Alternator connect to the chassis battery ONLY
Magnum inverter/Charger connects to the house batteries ONLY.

All charging between the house and chassis batteried is thru the white Rodgers solenoid. That is controlled by the BIRD. You need to shut that off.

I mention using the disabled White Rodgers solenoid as a juntion point for convenience, all connection you need are right there.

BIRD is a device that controls charging 2 ways, bi-directional. A battery to battery charger is a one way device. That's why you need a device ( Amp L Start ) to charge the other way. The BIRD can't do it.

[redbaron73]

Originally Posted by twinboat

BIRD is a device that controls charging 2 ways, bi-directional. A battery to battery charger is a one way device. That's why you need a device ( Amp L Start ) to charge the other way. The BIRD can't do it.

I looked up the Amp-L-Start and found the company has a lot of really good products, for a great price. I have just ordered their Toad-Charge to replace my failed RVI Toad Charger...Thanks for the info!


That AMP L Start is now on my list of products for my soon to come Lithium upgrade.


Site Link: LSL Products / LSLProducts.com - Problem-Solving Gear & Gadgets

[LibertyCall]

Thanks to everyone for the helpful and educating comments. Decisions, decisions!

[LibertyCall]

Originally Posted by creativepart

I did this project last April. I can tell you two things:

1. Looking at the wiring and all those solenoids looked super scary and really confusing. But after I started the project it actually turned out to be very logical and surprisingly straightforward.

2. The lithium batteries are really game changers. Very little storage discharge, very quick charging and consistent power at the ready.

The one thing I quickly learned was the need to maintain the chassis battery when not traveling. Traveling, the alternator keeps the chassis battery topped up. But, sitting in storage or on shore power in a campsite you need to add some way to maintain that charge. I added an “Amp-L-Start” to the mix of wires right there - which was super easy after learning the wiring from doing the install - and this fixed that problem for about $100.

Would you mind contacting me at stephenwilson1956@icloud.com? I have a couple more questions before I start playing with wires.
Thanks

[LibertyCall]

Originally Posted by twinboat

Intellitc is the smaller battery disconnect solenoid. You can see that it only has a large cable on one large terminal. The lower amp house loads are on the other side.

Charging between the batteries are done with the White Rodgers solenoid.

Alternator connect to the chassis battery ONLY
Magnum inverter/Charger connects to the house batteries ONLY.

All charging between the house and chassis batteried is thru the white Rodgers solenoid. That is controlled by the BIRD. You need to shut that off.

I mention using the disabled White Rodgers solenoid as a juntion point for convenience, all connection you need are right there.

BIRD is a device that controls charging 2 ways, bi-directional. A battery to battery charger is a one way device. That's why you need a device ( Amp L Start ) to charge the other way. The BIRD can't do it.

After re-reading this a few times and going back into the bay it seems to be clearer. If I'm understanding this correctly:
1. Remove wires from the BIRD - no other removals. (Tape and tag).
2. Connect DC2DC input to altenator (the pictured big red cable on the solenoid).
3. Connect DC2DC output to house batteries (the pictured big black cable).
4. Install Amp-L-Start between chassis and house batteries. Could I also put the chassis batteries on a charger when on extended stays? Not as convenient though.

[creativepart]

Originally Posted by LibertyCall

Would you mind contacting me at stephenwilson1956@icloud.com? I have a couple more questions before I start playing with wires.
Thanks

Actually Stephen, I don't mind emailing, but my install did not include the BIRD relay... I have a BIM. You have both a BIM and a BiRD and while I understand the processes involved our two RVs are setup different enough that I don't feel capable to advise you directly about the steps you need to take.

If you are looking for my help and don't want specifics then I'll be happy to help in general terms. OR help with other parts of the transition. Otherwise someone with a setup like yours would be your best bet for info.

As to the DC2DC charger hookup that you discussed with Twinboat on the post above... I felt confident I could power the DC2DC charger from the connections on the BIM (big red wire), but I went another way. I wired the Victron charger directly to my Chassis battery. The Victron is only 30-amp so all I needed was 10 gauge wire - but I used 8ga.

A plus for the Victron over all there other DC2DC chargers I looked at was that all the other chargers required a "trigger" wire to determine when the engine was running and the Victron auto senses this from the alternator output at the battery. That may not matter to you because I think you have such a trigger wire on the BiRD but I'm not positive. Since I have lots of other Victron pieces I also wanted the Dc2DC charger to be available on the bluetooth app, also.

[twinboat]

Originally Posted by LibertyCall

After re-reading this a few times and going back into the bay it seems to be clearer. If I'm understanding this correctly:
1. Remove wires from the BIRD - no other removals. (Tape and tag).
2. Connect DC2DC input to altenator (the pictured big red cable on the solenoid).
3. Connect DC2DC output to house batteries (the pictured big black cable).
4. Install Amp-L-Start between chassis and house batteries. Could I also put the chassis batteries on a charger when on extended stays? Not as convenient though.

Yes, you got it.

As far as the Amp L Start, that would go on the same 2 terminals of the DC2DC charger.

Pick up your ignition signal for your DC2DC charger from BIRD ign wire.