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Single Lithium Starter/Deep Cycle Battery with Outboard Motor

I'm having a hard time putting together all the info I've been reading on this topic. My boat has an outboard motor with an 18 amp/226 watt alternator. I'd like to run a single 12v lithium dual purpose battery (starting and deep cycle) because my current lead acid battery won't last a whole day of fishing due to the draw my electronics and livewell pump require. My trolling motor is on an isolated 24v system.

I'm trying to understand how to protect the alternator from overheating (due to over current) and from blowing up (due to overcharge cutoff).

Can anyone help?

tjbuggy2b asked

0 Answers

Can CerboGX gen start/stop relay work with SolidSwitch104?

On a boat, can I wire the gen start/stop relay on the CerboGX to a SolidSwitch104, which will be connected to the ignition wire on my Balmar voltage regulator?

The way I understand it, this is possible by connecting a 12v source to COM and then run a wire from NO to the SolidSwitch. And so I program the gen start/stop relay to go on at 30 SOC% and off at 75 SOC%, for example, should close the circuit, activating the SolidSwitch (and therefore closing the circuit on the ignition wire). When SOC% reaches the set value, the relay returns to NO state (opens again) and this de-activates the SolidSwitch (thus, stopping the alternator).

Is this right?

Thanks in advance!

jordanb asked

0 Answers

Orion-Tr Smart DC/DC control and grounding clarification


I am building a 24V setup very similar to the victron van install ( on a old Mercedes Benz truck (no smart alternator).

Instead of the Buck Boost, I will use the new Orion-Tr Smart 24/24-17A (400W) Isolated DC-DC charger behind a Battery Protect.

My negative bus bar and the enclosure of the MultiPlus are grounded to the chassis using 4mm2 wire.

The manual of the Orion-Tr Smart ( states on page 4:

"Remote on-off
Use the remote function to enable and disable the converter remotely with the remote on/off connector or using the
VictronConnect app. Typical use cases include a user operated
hard wired switch and automatic control by for example a Battery
Management System. If the minus of the service battery is not at
the same potential as the minus of the alternator or starter battery
an isolated remote on/off cable between the BMS and the on/off
port is required, see chapter 4.4 for details.

This should not be the case in a vehicle, but the on page 10, Figure 4:


there is an isolated remote on/off cable shown.

So here are my questions:

  • Is it correct to ground the negative bus bar and the enclosure of the MultiPlus to the vehicle?
  • Is it necessary to also ground the enclosures of the MPPT, the Orion etc. in such a setup?
  • Basically, I want to use the automatic "engine running" detection mechanism of the Orion-Tr to enable it. In case the VE.Bus BMS triggers the charge disconnect, the BatteryProtect on the charge side disconnects the Orion-Tr to protect the batteries. The question now is, if I also need to deactivate the Orion-Tr to protect it from beeing damaged, like with a MPPT? How would I do this? I have a "Non inverting remote on-off cable, ASS030550200" in my hands. It does not look like the one used in the diagram, it only has three cables (red, black, yellow).


kiko asked
Rod answered ·

1 Answer

Outboard alternator charging lithium


To charge a 12V LiFePO4 from an outboard alternator charging coil, what product is suitable to regulate the charging?

System Components

Outboard: Manual start, Honda BF6, 12V 6A charging coil
Battery: Lithium (LiFePO4), 12Ah, max charging rate 0.8C (9.6A)

Research Done

Watched the Victron Q&A Webinar 1 - Using an Alternator to charge Lithium video, and understand that since the battery has a larger C rating than the alternator, alternator current must be restricted using a Smart Orion or similar.

Victron Options Found

Using the VictronConnect app to check the interfaces via the demo mode. Nothing appears suitable:

- Phoenix Smart Charger IP43 12|30 has "maximum charge current" settings of 7.5A, 15A and 30A, the minimum is too high for the alternator.

- Orion Smart 12V|14V-18A Isolated has a LiFePO4 battery preset but no current limit settings (just voltage), and it isn't clear if it's ok with the variable output from an outboard.

- Blue Smart Charger 12|5 can limit charging to 2A or 7A, but is mains powered, and the 2A lower limit loses 4A of potential charging, while the 7A upper limit is too high for the alternator.

- SmartSolar Charger 100|15 can limit charging on a variable scale in 1A increments, but it's inputs are designed for panels only (MPPT controller won't turn on until incoming voltage exceeds Vbat + 5V. Thereafter the minimum PV voltage is Vbat + 1V), it's also unclear what the MPPT varying the exposed load will do to the outboard coil.

Non-Victron Options Found

- Sky RC B6 Charger + Sterling Alternator Protection Device this combination is promising. The B6 charger can tolerate a range of input from 11-18V, and 6A maximum output. SkyRC were unclear under what circumstances the battery would be disconnected, and so there is a danger of damaging the alternator by having the battery disconnected during engine running.

This danger can be minimised using a Sterling device that provides an emergency route for current in the case of disconnection or failure. Sterling device is waterproof.

The battery pack accepted in the spec of the B6V2 is 100-50000mAh (unclear what happens if the battery is over-spec). Also Victron members mention it being difficult to configure. It is not waterproof and so extra weather protection must be added.

Which Victron product will allow the charge to be limited to a safe current for the alternator?


I am in a 3m open-top inflatable boat so the system needs to be compact, light, and simple.

Update May 2022: added promising (unfortunately non-Victron) option

With the existence of the alternator protector, any charging product that can accept variable and lumpy voltage inputs of ~5V-18V while limiting output to 6A and disconnecting if overloaded seems like the perfect solution.

neepsandtatties asked
neepsandtatties edited ·

8 Answers

How to measure two DC Inputs On CCGX

I am looking to install a Victron system on my RV that will be using a third-party DC-DC charger to charge 48v house batteries from the vehicle's 12v alternator. If I were to connect this charger through a dedicated BMV battery monitor (with a second one for the system's DC loads), is there any way to have one show up as an "alternator" input on the CCGX display screen?

I know I could connect it through the BMV-700 and presumably just have the CCGX show it as power flowing from the "DC loads" box to the battery. My primary concern is ease-of-use for the end user, so I would greatly appreciate any way to configure thte CCGX for this display.

chase-martin asked
leedyson1 commented ·

4 Answers

Orion 12/24-10A wiring questions

2 questions;

I have a boat with a house bank of batteries, and I wish to feed 12v from there to my new 24v bank of batteries in the bow for a newly installed bow thruster.

I already have a set of heavy cables (4/0) running about 25ft from the house bank up to my 12v windlass (very tip of the bow). I want to install this dc-dc charger in the bow next to my thruster batteries and thruster on a nice new wood panel with all the electrical stuff mounted on it. Ideally I would like to cut into those 4/0 cables, about 75% of the way to the bow, add some battery "posts" and then carry those on to the windlass. This way I could connect my 12v side of my orion charger to those posts, and feed my 24v bank. Otherwise I will need to run two more sets of #6 wire (+ and -) or larger another 25ft from the alternator or house bank.

1) Does the dc-dc charger HAVE to be connected to my alternator to sense it, or can I simply connect it to my 12v bank via the existing 4/0 cables (I am thinking it would sense the voltage rise when the alternator starts charging my house bank and turn on?)

2) It states that I need to run #6- but when this is only 10A @ 24v. max fuse is like 25A, so I am thinking I can just run #10 on both the 12 and 24v side of this converter and that should be adequate- assuming I don't have that long run to my house bank- just 2-3ft from the converter to the battery posts. Thoughts?

Thanks, Ty.

jointcustody asked
kevgermany answered ·

1 Answer

Small alternator 16A with Lithium


What recommendation would you share to charge 90Ah LiFePO4 with an alternator rated 16A.

Alternator is not a smart version, don't have any control in case of high temperature.

I'm quite sure that putting it without any Orion-Tr Smart would blow the alternator in a while.

OrionTr-Smart 12/12-18 is almost good, but since cannot set the current limit, it doesn't help too much.



lucasnowak asked
deminimis answered ·

1 Answer

Orion-Tr 12/12 30 directly connected to the alternator


I am using since a while LifePO4 batteries on my boat.

Each battery features an active BMS + balancing.

The starter battery is a 20Ah (CCA of 400A for 5s), while the service battery is an 80Ah battery.

Between them there is a Septor 1275 which allows for charging more than one battery.

The starter battery is connected to the alternator (Hitachi 80A on an Yanmar 3YM20 engine).

For regatta, all fine. For cruising (10hr +), the service battery does not get completely charged when motoring.

I was planning to fit in an Orion-Tr-Smart charger between the alternator and the rest of the circuit (starter battery followed by the Septor 1275 followed by the service battery).

Any drawback in doing so? why is this case not covered by the reference schematic considered?

I understand the Orion is a B2B, but what is actually the diff compared to an A2B in this case?

Any feedback, suggestion, welcome.



ger50 asked
Sarah commented ·

6 Answers

Orion 12|12-30 not charging

I have just installed an Orion 12|12-30 into my 2012 sprinter van. I’m running 3 206Ah LiFePo4 batteries (eventually plan on getting a second alternator). I am not getting a current output while driving which I believe should be around 30A. I’ve adjusted my settings but still seem to be having issues. Start voltage: 14, delayed start voltage: 13.8, delayed start voltage delay: 120s, shutdown voltage: 13.5 input voltage lockout: 12.5V / 12.8V

klf93 asked
klf93 commented ·

1 Answer

Lithium batteries on a 250hp Outboard motor, how to protect alternator (start and house batteries)

I need to increase the capacity of the house batteries for my boat. At the same time I need to keep or preferrably reduce the weight of the boat (I'm at the weight limit when trailering the boat).

Preferrably I would like to replace 2x Tudor 115Ah Dual Marine (60kg) with 1x Li starter battery and 2x Li house batteries (100Ah starter and 2x100Ah House).

Alternator puts out max 46A.

What is needed to ensure a NON overheated alternator?

See picture for separated starting and accessories batteries direcly at the alternator:


daycruiser asked
ww2bar commented ·

4 Answers

Lithium Batteries Location, max cable Length / size between alternator, charger and batteries


planing to change the battery bank on my boat. I wonder if there is any recomentation where to place lithium batteries in relation to alternator to charger to battery bank. Max cable lenght and sizes between the parts.

Thanks for your help


marka asked
marka commented ·

2 Answers

12 volt alternator charging a 48 volt LiFePo4 battery bank

Can I use two Orion-Tr 12/24 DC to DC chargers with outputs wired in series?

pdxagogo asked
kevgermany answered ·

1 Answer

Monitoring alternator temperature with CERBO GX to regulate a Buck/Boost charger


Here is the main idea, not sure if it's possible.

I have a 180A alternator on my sprinter 2020 and I want to install two DC-DC Sterling 12->48V of 70A each to charge 6Kw of Lithium batteries.

I want the Cerbo GX to monitor the alternator temperature and disconnect one of the two sterling when there is too much heat.

Is that feasible ?

Thanks !

sebcbien asked
sebcbien edited ·

3 Answers

Second Alternator + DC-DC Charger

Hello everyone,

I am building a power system in a Sprinter and would like some advice on an idea I have.

I am installing a second alternator with Wakespeed controller connected to a Victron Lynx System (BMS and Distributor Busbars) controlled by a Cerbo GX. I am installing a 1320ah battery and am trying to figure out how to charge it as fast as possible.

So now to my question, it is a dumb idea to also add a Orion-Tr charger off of the starter battery/chassis alternator to the power-in busbar get additional charging? Or is this going to cause issues with the system as is?

This is pretty similar to what I have but with a 120v x2 3k inverter charger:

Also curious about wiring since the Wakespeed and Orion-Tr both use the BMS ATC connection

Any advice is greatly appreciated

trenton-smith asked
nebulight answered ·

1 Answer

Wiring a quattro and alternator to charge 2 battery banks

I am replacing my existing battery charging and inventor system. Can i connect my alternator and the Quattro to the Argofet input terminal? (my existing splitter does this)

I read that the Quattro trickle charge terminal should be used for the starter batteries rather than the main Quattro charge output. Also keeping the alternator dedicated to the starter battery.

If i cannot connect to shore power for some timed the barge will need all batteries charged from the alternator and not the Quattro. Hence, the Argofet would do the job if i can connect a common input from Charger and alternator.

Your guidance is very welcome


miltonmews asked
miltonmews commented ·

1 Answer


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