New Boat: Lithium Now or Later

[SV-Viento]

Originally Posted by SV Confianza

There was a decent amount of rewiring and then adding sensing wires. This could be solved by just asking them to wire the alternator to charge the house bank, and then have the house bank charge the starter banks, so it will be easier to do LFP later.

Feeding wires through conduit that was waterproofed was fun. A good amount of expensive battery cable had to be tossed and new ones made. I didn't want to extend cables that were too short to add resistance points.

I had to replace my alternators, though, and wire the regulators, since those didn't exist. So if you were already planning alternators capable of charging LFP with external regulators, that makes it easier. I know some may argue, but you'll want beefier alternators for LFP. Your power usage will grow a bit to your power ability, and alternators used for a LA setup will probably be inadequate. The minimum small case alternator that I would recommend is the Balmar xt170.

Lots of other good comments here, but I think Statistical has a good point about the warranty. Will they start blaming any issues on your modifications to the electrical system. That alone might be worth just some negotiation with them on price of the LFP setup, or making sure the warranty will still be valid if they wire the LFP and you can make your own choices.

If you're interested in what our setup looks like, I documented it here: https://www.clevermariner.com/post/c...work-from-boat

Just a BIG Thank YOU!!!!!!!! for your thoughtful response and link to your blog. I just started to read - it will be super helpful.

[SV Confianza]

Originally Posted by SV-Viento

Just a BIG Thank YOU!!!!!!!! for your thoughtful response and link to your blog. I just started to read - it will be super helpful.

Just glad to see people get some use out of it =). I got lots of help from other content creators like Rod Collins (CMI), Steve Mitchell (Seabits), and Ben Ellison and Ben Stein (Panbo), etc etc. Figured I'd try to give my experiences back to the community.

Feel free to DM me if you've got any questions about how things might play out in the real world. I don't claim to be the world's foremost expert or anything, but we've been playing with our LFP setup for a couple of years now.

I just realized that I really need to add a table of contents to that post or something. It is quite....long.

[Senojev]

I would definitely do a post delivery conversion to lithium. Your inverter charger and an alternator are both lithium capable. Why would you want to increase the capability of your inverter/charger? If it is capable of supporting 640Ahr of AGM it will support a smaller lithium bank. If you think you may want to go with a larger lithium bank in the future, it may be worth increasing the size now and at least the cabling, etc. will already be in place. Converting to lithium in the future would be relatively easy and significantly cheaper, especially as lithium is dropping in price.

[Adelie]

Originally Posted by Senojev

I would definitely do a post delivery conversion to lithium. Your inverter charger and an alternator are both lithium capable. Why would you want to increase the capability of your inverter/charger? If it is capable of supporting 640Ahr of AGM it will support a smaller lithium bank. If you think you may want to go with a larger lithium bank in the future, it may be worth increasing the size now and at least the cabling, etc. will already be in place. Converting to lithium in the future would be relatively easy and significantly cheaper, especially as lithium is dropping in price.

The OP indicated FLAs in the original post, unless I missed a clarification somewhere.

If he was going to hang on to the lead cid batteries for a while I would suggest Gels or FLAs over AGMs.

[Senojev]

Adelie

My mistake … the OP did say that the house bank option would be FLA or lithium but other loads such as electric winches would be from AGMs. He also said that one alternator would feed both the FLA and the AGMs. If this is the case, going with AGMs for the house should be considered. Increased cost but may be worth it if he can keep the AGMs fully charged regularly. Plans to add solar would help in this regard.

[kmacdonald]

Changing to lithium is very simple. $30K is rediculous. 560AHr @ 12V is about $2K. Just about all new solar charge controllers can be programmed for lithium and most externally regulated alternators can also be programmed for lithium. If you dont know how to do it yourself you shouldnt have lithium. A few days reading will teach you enough to do it yourself.

[SV-Viento]

Originally Posted by Senojev

I would definitely do a post delivery conversion to lithium. Your inverter charger and an alternator are both lithium capable. Why would you want to increase the capability of your inverter/charger? If it is capable of supporting 640Ahr of AGM it will support a smaller lithium bank. If you think you may want to go with a larger lithium bank in the future, it may be worth increasing the size now and at least the cabling, etc. will already be in place. Converting to lithium in the future would be relatively easy and significantly cheaper, especially as lithium is dropping in price.

This is the likely direction we head. We Have asked builder for more detail and will simply plan to make modifications to lithium post delivery.

[SV-Viento]

Originally Posted by Adelie

The OP indicated FLAs in the original post, unless I missed a clarification somewhere.

If he was going to hang on to the lead cid batteries for a while I would suggest Gels or FLAs over AGMs.

Op here - and you are correct the builder is at this time supplying FLAs for the house bank. I would prefer AGMs if not lithium but they have strong opinions that differ from mine and simply have two options FLA or lithium.

[kmacdonald]

Originally Posted by SV-Viento

Op here - and you are correct the builder is at this time supplying FLAs for the house bank. I would prefer AGMs if not lithium but they have strong opinions that differ from mine and simply have two options FLA or lithium.

Nothing wrong with FLA.

[SV-Viento]

Originally Posted by kmacdonald

Changing to lithium is very simple. $30K is rediculous. 560AHr @ 12V is about $2K. Just about all new solar charge controllers can be programmed for lithium and most externally regulated alternators can also be programmed for lithium. If you dont know how to do it yourself you shouldnt have lithium. A few days reading will teach you enough to do it yourself.

In concept I totally agree with you and have read enough to know to read and ask more . The big question, ask up thread is will insurance allow me to do the work. If not, it will still be less costly to have it done post delivery.

[kmacdonald]

Originally Posted by SV-Viento

In concept I totally agree with you and have read enough to know to read and ask more . The big question, ask up thread is will insurance allow me to do the work. If not, it will still be less costly to have it done post delivery.

It will certainly be much less post delivery. Id guess 75% or more less if paying someone to do it. $3K or less if you do it.

[SV-Viento]

Originally Posted by kmacdonald

Nothing wrong with FLA.

We had and I installed a simple but very nice AGM system in our last boat. It worked great for our use case. But builder has strong thoughtful opinions/logic on why they go with FLAs for house bank. And they aren’t wrong it will be a very nice FLA house bank BUT if cost were not so insane we would do lithium now. So, will sleep on it a couple more days need to let them know Monday.

[kmacdonald]

Cost/Reward is always a consideration. FLA and lithium both deliver power and get the job done but Lithium doesn't do it $30K better. $5K is even a stretch. $3k, jump on it.

[mako]

Since options via a dealer are generally about 4X more expensive than what you could retrofit yourself, the answer is obvious, as stated numerous times already. However, I wouldn't waste a new build with a 12V house bank. It's easy enough to specify a 24V system and shouldn't be much of a cost. That would be a better investment of your money at this time.

Certainly if you're planning one day to upgrade to full Aircon, induction stove, washer/dryer, etc., then you may consider paying the costs upfront for a 48VDC main bank.

Then a simple 12V AGM starter battery, isolated.

[SV Confianza]

Originally Posted by mako

Since options via a dealer are generally about 4X more expensive than what you could retrofit yourself, the answer is obvious, as stated numerous times already. However, I wouldn't waste a new build with a 12V house bank. It's easy enough to specify a 24V system and shouldn't be much of a cost. That would be a better investment of your money at this time.

Certainly if you're planning one day to upgrade to full Aircon, induction stove, washer/dryer, etc., then you may consider paying the costs upfront for a 48VDC main bank.

Then a simple 12V AGM starter battery, isolated.

I will second that! I really wish when we did our refit we went 24v instead of 12... I didn't want to replace the other 12v stuff, but I have since replaced a lot of it anyway. If I had to do it again, I would certainly go 24v in a heartbeat. I'm already reaching limitations of 4/0 cable with the lithium setup.