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Russ wrote: ↑Fri Sep 12, 2025 6:26 am Are you planning on charging the LiFePO4 batts ONLY from solar? Keeping the motor on its own start battery? The way you use your boat, that would probably work fine.
Isolated batteries with different charging probably saves the challenge of 12v charging the LiFePO4.


You don't show a fuse/breaker going to the (5 Switch w /fuse USB & out) or the (6 fuse block).

I use one of these to fuse that run.




I see you have a breaker between the solar panels and the controller. I don't have this fused/breakered. It's probably a good idea though.

• If you don't have any loads on the start battery other than the starter then you should never wake up to find it dead. You shouldn't but you will so get a booster pack. Murphy always finds a way onboard.

• A single positive bus bar and a single negative bus bar can make wiring neater.
  • One properly sized and fused positive cable will be the only thing connected to your positive post.
  • One properly sized negative cable will be the only thing connected to your negative post.
  • All charge sources can be connected directly to the positive and negative bus.

• Unless you have a good reason (and on a plastic boat I can't think of one) all of your DC negative cables should be connected together, preferably at a common bus bar.

• Over-current devices protect wires. They should trip well before the wire can be damaged and never trip under normal loads. Nuisance trips are more than a nuisance. They are either a design problem or a failing over-current device.

• Safety equipment (VHF, AIS, radar, horn, navigation lights, steaming light, anchor light, bilge pump) should be connected to a dedicated circuit.
  • If possible put each on its own dedicated circuit.
  • Avoid using switched circuits. If the master switch (usually your Perko) is on, then the safety equipment should be powered. If the safety equipment does not have its own switch (ex: some AIS units) then a switched circuit would be preferable.

• Low voltage DC circuits will have significant voltage drop over surprisingly short distances. Some devices don't care; some are very picky. Current is not the only reason to use a larger wire. Sometimes you have to do it to keep your voltage at an acceptable level.

• Almost every electrical thing you bring from home is going to need a lot more power to run than you probably expect. Make sure you really want it and design for it appropriately.

• TANSTAAFL.
  • If you change voltage (think USB charger in 12V socket) you will consume more power than the charger is providing.
  • If you change DC to AC (inverter) you will consume more power than the inverter is providing (sometimes a lot more).
  • If you charge a battery (tablet, phone, laptop...) by plugging into an inverter you will use a lot more power than the battery is receiving.

• Try to maximize inefficient operations (see above) during times when you have excess power production (shore power, daytime with solar, ...)

Russ wrote: ↑Fri Sep 12, 2025 10:23 am You are using LiPO4 and I need to learn more about them. My understanding is they don't have the problem of losing power just sitting idle like lead acid do. So disconnecting them makes sense.

I have some 12v stuffs running all the time. A 12v WiFi switch, Cell phone wifi hot spot and a wifi camera. So I need 12v power constantly and the solar panel works fine for that.

You seem to have a good handle on the wiring and it seems to work well for you with all your power needs.

I found this about fusing:

For 12-volt marine systems, the American Boat & Yacht Council (ABYC) standard E-11 requires that fuses or circuit breakers be located within 7 inches (178 mm) of the power source, measured along the conductor. The purpose is to protect the wiring from overheating and causing a fire, especially in the event of a short circuit.

Sounds like you are good on this.

Be Free wrote: ↑Fri Sep 12, 2025 11:00 am Your design is starting to take shape. Good job! I think keeping your outboard connected directly to your lead battery is a very good idea.

Some design goals to consider:

• If you don't have any loads on the start battery other than the starter then you should never wake up to find it dead. You shouldn't but you will so get a booster pack. Murphy always finds a way onboard.

• A single positive bus bar and a single negative bus bar can make wiring neater.
  • One properly sized and fused positive cable will be the only thing connected to your positive post.
  • One properly sized negative cable will be the only thing connected to your negative post.
  • All charge sources can be connected directly to the positive and negative bus.

• Unless you have a good reason (and on a plastic boat I can't think of one) all of your DC negative cables should be connected together, preferably at a common bus bar.

• Over-current devices protect wires. They should trip well before the wire can be damaged and never trip under normal loads. Nuisance trips are more than a nuisance. They are either a design problem or a failing over-current device.

• Safety equipment (VHF, AIS, radar, horn, navigation lights, steaming light, anchor light, bilge pump) should be connected to a dedicated circuit.
  • If possible put each on its own dedicated circuit.
  • Avoid using switched circuits. If the master switch (usually your Perko) is on, then the safety equipment should be powered. If the safety equipment does not have its own switch (ex: some AIS units) then a switched circuit would be preferable.

• Low voltage DC circuits will have significant voltage drop over surprisingly short distances. Some devices don't care; some are very picky. Current is not the only reason to use a larger wire. Sometimes you have to do it to keep your voltage at an acceptable level.

• Almost every electrical thing you bring from home is going to need a lot more power to run than you probably expect. Make sure you really want it and design for it appropriately.

• TANSTAAFL.
  • If you change voltage (think USB charger in 12V socket) you will consume more power than the charger is providing.
  • If you change DC to AC (inverter) you will consume more power than the inverter is providing (sometimes a lot more).
  • If you charge a battery (tablet, phone, laptop...) by plugging into an inverter you will use a lot more power than the battery is receiving.

• Try to maximize inefficient operations (see above) during times when you have excess power production (shore power, daytime with solar, ...)

Finally, regardless of what you end up doing, label and document every wire, switch, connection, and fuse. I can guarantee that you will not remember what you did or where it was no matter how clear it is in your mind today. "Future You" will thank "Present You" next year when that "thing" stops working in the middle of the night.

Be Free wrote: ↑Fri Sep 12, 2025 11:00 am Your design is starting to take shape. Good job! I think keeping your outboard connected directly to your lead battery is a very good idea.

Some design goals to consider:

• If you don't have any loads on the start battery other than the starter then you should never wake up to find it dead. You shouldn't but you will so get a booster pack. Murphy always finds a way onboard.

Enjoyed this entire thread of info and the video Tuxon Pup! Question for everybody, I am going to be buying a booster pack (just in case) for my Honda 50 HP 4 stroke. Does anyone have preferences on what to purchase? I of course would want to be able to recharge it with 12 volt. Thanks for the help

FittsFly wrote: ↑Tue Nov 11, 2025 5:45 am
Enjoyed this entire thread of info and the video Tuxon Pup! Question for everybody, I am going to be buying a booster pack (just in case) for my Honda 50 HP 4 stroke. Does anyone have preferences on what to purchase? I of course would want to be able to recharge it with 12 volt. Thanks for the help

Russ wrote: ↑Tue Sep 02, 2025 6:15 am I'm going to second the problem with the "gray marine" fuel line. That was my "new" hose to replace the original fuel line (which was still fine). I thought it was too old and I should replace it.

THIS is what happened after 2 weeks of use. It literally crumbled and who knows what that junk inside did. I replaced the fuel filter after that.







THIS is what I replace the "cheap" prefab fuel line with. Bought primer bulb and connectors and made my own fuel line. I have another as a spare.
https://www.amazon.com/dp/B0B6TTNN7H?re ... tails&th=1