Lifepo4 Batteries

[Midnightsun]

My memory is definitely not what it used to be. I do remember my name though so that's a good thing right?

Why don't we start now? Make that link a sticky in the electrical/battery section with an appropriate title.

[Midnightsun]

Here is another eye opener, at least for me it was. Take the time to listen and learn here but do keep in mind this is more for RVs with a single alternator which usually do rely heavily on charge via the alternator when compared to a boat.

[DarylB]

Hi all,

I am looking to purchase a Bluetti AC300 (3kW Inverter) with 1 BS300 (3072Wh Battery). This would allow my 120V 30A shore power to pass thru. When not on shore power the Bluetti will provide my 120V. My second 120V 30A shore power is for Air Conditioning and will stay separate.

Your thoughts.

[km1125]

I'm not familiar with the Bluetti at all, but on a boat you really need to understand how the inverter handles the neutral and ground connections, especially with the pass-through feature. What it SHOULD do is isolate the inputs and then connect the neutral and ground when it's in "inverter" mode, but disable that connection when it is in "pass-through" mode.

Also consider how you're going to recharge it, especially if you need to recharge on the boat, rather than via shore power. 3kW is a lot of capacity and would probably take a bit to recharge.

[Midnightsun]

The Bluetti seems more like a portable backup solution or if you want, a gas free generator with a heck of a lot of cool options so not sure how this would connect to the boat other than the way you would connect a portable generator. Guess the official name of these are "portable power stations". I see you could connect a 30a shore power cord from it to the boat which would power up everything just like if you were on shore power however nothing about pass thru. I cannot see how this type of unit would be of benefit on a boat plus the cost is up there considering this is almost equivalent to a single 12v 300aH LifePo4 battery if my math is right. https://www.bluettipower.ca/products/ac ... 20Shopping

Here is a good rated unit with a smaller 2100wh integrated battery. Which is about 1/3 less than the Bluetti however you can see it can run a coffee maker for 3hrs before needing a charge which is OK but nothing to write home about and as already mentioned you got to get the juice back in to use it again. This one cannot do 30a like the Bluetti though but gives you some run times in the add which will be helpful in your decision. https://ca.jackery.com/products/explore ... anic&gad=1

[DarylB]

Thanks for the replies above!

The AC300 has a 30A AC input and output. It is a full UPS so will pass thru my shore power when plugged in. The shore power will also charge it.

I am looking at putting this between the shore power input and the panel so it will always be in use.

[Midnightsun]

Here is what it now looks like with 3x 300ah LifePo4 units for a total of 900AH. EDIT, no I did not capsize.

IMG_2765.jpg

[KyleR]

Hi Hans,

I know this is an older thread, but one concern you voiced early on was not having the alternator redundancy provided by the isolators which you replaced with the DC-DC chargers.

Did you ever address this or did you just leave the alternators "separated"? If so, any issues or concerns come up so far?

Thanks for the great write-up and ongoing updates through your process!!

[Midnightsun]

No issues whatsoever. I have kept the isolators in place so I actually do have alternator redundancy. All works as expected after almost 2 season. Best upgrade one can make.

[KyleR]

So your alternators go to your isolators, which feed your house batteries, which then feed your lithium bank via the DC-DC chargers? Is that right?

The reason I ask is because this is the exact same setup/conclusion I came to when planning our lithium conversion. It's good to read about an almost identical install that is working properly!

We're just going with 200ah of lithium (for now ) as we have very low usage - but like to be on anchor as much as possible! If we ever decide to add an inverter I would definitely want a larger house bank, but for now 200ah will be great!

Thanks again!