GT5 Lithium - Is it really this difficult?

[bnaudie]

I want to exchange my two lead acid coach batteries for three Battle Born 100Ah lithium batteries.

I want to preserve the ability to charge chassis battery from coach converter and to charge coach (new lithium) batteries from chassis alternator, when necessary. And also to have battery boost switch from one set of batteries to the other.

GT5 came with SDC-107A battery control. It apparently does more than just isolate/connect battery systems. It also has onboard fuses and power panel for some various equipment. But it is not compatible with lithium voltage requirements. I do not want to do circuit board voltage tweaking.

The typical isolator that Battle Born uses is Precision Circuits Li-BIM 225, but it only does isolate/parallel switching – no provision for the fuses and power panel built in to OEM device.

QUESTIONS
Can I pull the isolate/parallel function from existing SDC-107A and leave the fuse and power panel functionality as is? And use the Li-BIM 225 to do battery isolation? Has anybody done this? Or something else?

EQUIPMENT LIST
2018 Georgetown GT5 31L5

Chassis Battery - Motorcraft ML BXT-65-750, 750cca, 935ca, 140 Reserve Capacity, Wet Cell

Ford V-10 Alternator Size (output)??

Current Coach (house) Batteries (2):
*Date Stamp Jan. 2018
*27MDP dual purpose lead acid
*160 Minutes Reserve Capacity

Coach Battery Compartment
*15" wide (15-3/4 max)
*19" deep (19-3/4 max)
*Should accommodate (2) GC2 and a single conventional 100Ah Battle Born

RV Custom Products Battery Control Center SDC-107A (disconnect/isolator)

Progressive Dynamics INTELI-POWER PD9270 Converter/Charger – 70-amp output.
*Lithium Replacement Model: Progressive Dynamics PD9170ALV

Progressive Dynamics PD52 Automatic Transfer Relay Switch – Current Rating: 50A line, 70A neutral

Xantrex Freedom Xi Inverter 2000 watts, sine wave

Cummins Onan Generator RV QG 5500 (5500 watts, 45.8 amps)

[Iggy]

Wow.
I have been in electrical/electronics all my life and have no idea about what you are planning to do.

Sure you can do it but.............

Why is the question that comes to mind first.

Do you expect to live in your Georgetown for 10 plus years?

Do you plan on using solar to recharge your batteries or just shore power?

Do you plan on increasing the battery charger in the Georgetown from 70 amp to a larger one?

Do you know that the engine Alternator is I believe only 75 amps.

I suspect you are highly skilled as you seem to know what you are talking about in most of your statements but back to my 1st question why do you what to go thru all this cost, change outs, and the possibility it may not work?

[rk06382]

Originally Posted by bnaudie

I want to exchange my two lead acid coach batteries for three Battle Born 100Ah lithium batteries.

I want to preserve the ability to charge chassis battery from coach converter and to charge coach (new lithium) batteries from chassis alternator, when necessary. And also to have battery boost switch from one set of batteries to the other.

GT5 came with SDC-107A battery control. It apparently does more than just isolate/connect battery systems. It also has onboard fuses and power panel for some various equipment. But it is not compatible with lithium voltage requirements. I do not want to do circuit board voltage tweaking.

The typical isolator that Battle Born uses is Precision Circuits Li-BIM 225, but it only does isolate/parallel switching – no provision for the fuses and power panel built in to OEM device.

QUESTIONS
Can I pull the isolate/parallel function from existing SDC-107A and leave the fuse and power panel functionality as is? And use the Li-BIM 225 to do battery isolation? Has anybody done this? Or something else?

EQUIPMENT LIST
2018 Georgetown GT5 31L5

Chassis Battery - Motorcraft ML BXT-65-750, 750cca, 935ca, 140 Reserve Capacity, Wet Cell

Ford V-10 Alternator Size (output)??

Current Coach (house) Batteries (2):
*Date Stamp Jan. 2018
*27MDP dual purpose lead acid
*160 Minutes Reserve Capacity

Coach Battery Compartment
*15" wide (15-3/4 max)
*19" deep (19-3/4 max)
*Should accommodate (2) GC2 and a single conventional 100Ah Battle Born

RV Custom Products Battery Control Center SDC-107A (disconnect/isolator)

Progressive Dynamics INTELI-POWER PD9270 Converter/Charger – 70-amp output.
*Lithium Replacement Model: Progressive Dynamics PD9170ALV

Progressive Dynamics PD52 Automatic Transfer Relay Switch – Current Rating: 50A line, 70A neutral

Xantrex Freedom Xi Inverter 2000 watts, sine wave

Cummins Onan Generator RV QG 5500 (5500 watts, 45.8 amps)

Look at my post:

Originally Posted by rk06382

I was able to adjust the BCC BIRD trip voltages to 13.45v.
See post: How to adjust SDC-107A BCC for Battle Born batteries #17.



Conclusion:
I am happy with the results. The SDC-107A BCC is now safe to use with my Battle Born batteries. I have isolation when there is no charger raising the voltage above 14v.

[bnaudie]

Originally Posted by Iggy

Wow.
I have been in electrical/electronics all my life and have no idea about what you are planning to do.

Sure you can do it but.............

Why is the question that comes to mind first.

Do you expect to live in your Georgetown for 10 plus years?

Do you plan on using solar to recharge your batteries or just shore power?

Do you plan on increasing the battery charger in the Georgetown from 70 amp to a larger one?

Do you know that the engine Alternator is I believe only 75 amps.

I suspect you are highly skilled as you seem to know what you are talking about in most of your statements but back to my 1st question why do you what to go thru all this cost, change outs, and the possibility it may not work?

Hi Iggy,

Haha.... thanks for your comments and concern.

Motor home came with coach batteries and chassis battery. Traveling - all batteries are charged by the V10. Parked - all batteries are charged by the converter. Both systems protect against overcharging.

My wife and I are planning on living/traveling in the RV until we don't want to anymore. Not promised tomorrow so living for today.

I do have 120 watts of solar right now but that's for prior small RV. I will use it to supplement/reduce need for generator now.

Battle Born lithium battery actually prefers less than 100 amp alternator to prevent overcharging. They have battery management system to prevent overdraw of alternator.

We boondock about 1/3 of the time and do not want to run generator more than I have to - personal preference.

I think the concept is pretty straightforward. I may have overcomplicated the first explanation:

It looks like you have a Forest River GT. We probably have the same battery control center. I'm sure you enjoy/use the ability to charge all battery systems whether parked or traveling. Me too.

But the battery control center that Forest River uses is pretty unique. They include a power and fuse center with the battery isolator, where most RVs just have a dedicated device for battery isolation. And the device they use doesn't operate at lithium voltages.

So.... I cannot just swap devices because I need to leave the power and fuse center. I just want to disable the battery isolator functionality from my current unit and install a standalone battery isolator that supports lithium.

The good news is that the manufacturer of the existing battery control center has provided the schematics that show which wire (just one wire) that I can pull off the coil relay to disable the battery isolator.

And then I can install the standalone lithium battery isolator that will work. But I will test and confirm first - before buying new batteries. Stay tuned....

[Iggy]

Originally Posted by bnaudie

Hi Iggy,

Haha.... thanks for your comments and concern.

Motor home came with coach batteries and chassis battery. Traveling - all batteries are charged by the V10. Parked - all batteries are charged by the converter. Both systems protect against overcharging.

My wife and I are planning on living/traveling in the RV until we don't want to anymore. Not promised tomorrow so living for today.

I do have 120 watts of solar right now but that's for prior small RV. I will use it to supplement/reduce need for generator now.

Battle Born lithium battery actually prefers less than 100 amp alternator to prevent overcharging. They have battery management system to prevent overdraw of alternator.

We boondock about 1/3 of the time and do not want to run generator more than I have to - personal preference.

I think the concept is pretty straightforward. I may have overcomplicated the first explanation:

It looks like you have a Forest River GT. We probably have the same battery control center. I'm sure you enjoy/use the ability to charge all battery systems whether parked or traveling. Me too.

But the battery control center that Forest River uses is pretty unique. They include a power and fuse center with the battery isolator, where most RVs just have a dedicated device for battery isolation. And the device they use doesn't operate at lithium voltages.

So.... I cannot just swap devices because I need to leave the power and fuse center. I just want to disable the battery isolator functionality from my current unit and install a standalone battery isolator that supports lithium.

The good news is that the manufacturer of the existing battery control center has provided the schematics that show which wire (just one wire) that I can pull off the coil relay to disable the battery isolator.

And then I can install the standalone lithium battery isolator that will work. But I will test and confirm first - before buying new batteries. Stay tuned....

Bruce this helps me comprehend why. "We boondock about 1/3 of the time"


Here is some info on the battery control center I have and probably the same as what you have.

[NXR]

I thought I read that the SDC-107A was no longer available if it fails. The 2019.5 and 2020 use a Precision Circuits BCC instead. If you're going to do all of that work you might want to query FR on that subject and if accurate, bite the bullet and change the BCC out as well.

Ray

[bnaudie]

Originally Posted by NXR

I thought I read that the SDC-107A was no longer available if it fails. The 2019.5 and 2020 use a Precision Circuits BCC instead. If you're going to do all of that work you might want to query FR on that subject and if accurate, bite the bullet and change the BCC out as well.

Ray

Thanks for this NXR. That would be sweet! I have an email in to FR....

[rk06382]

Originally Posted by NXR

I thought I read that the SDC-107A was no longer available if it fails. The 2019.5 and 2020 use a Precision Circuits BCC instead. If you're going to do all of that work you might want to query FR on that subject and if accurate, bite the bullet and change the BCC out as well.

Ray

I purchased a replacement SDC-107A direct from RV Custom Products.
See thread My coach batteries stopped charging from the alternator. (Bad SDC-107A)

With technical help from RV Custom Product, I was able to change the charge voltage of the SDC-107A to work with my Battle Born LiFePO4 batteries.

I monitor the chassis battery with my Victron BMV-712.