Fighting against "best"

[ThereAndBack]

So I finally bought myself another boat. She needs some work. I go about doing the things that need doing. Most recently, the dink.

I ended up with a 10ft aluminum RIB with a 15hp electric start. Do I need such a thing? Not really. I survived for years in a little portabote with a 3.5hp, but I wanted it.

Now it is time to change the batteries. The boat has 6 x GC2 batteries in it. I know I can throw 8 GC2 batteries in and have roughly 400 usable amp hours, but I'm contemplating putting lithiums in. That will of course mean changing the charge sources and all the other things.

And after that, maybe time for new solar and wind gen?

I don't have unlimited funding. Prioritization is hard. How do you reel it in and just go with "good enough" sometimes?

[Tillsbury]

It is tough. I try to prioritise the worst things (once safety is sufficient). I upgrade the worst system to as good as possible. I wouldn’t want to upgrade to a half-baked solution, I’d rather skip it if funds are tight and come back to it later.

Do the batteries really need replacing now? Can you upgrade the generation a little first, which would mean crummy batteries wouldn’t be shown up so much? Then budget to go all out to really nice new batteries in a year or two?

That or go to a small lithium setup with just sufficient power, knowing you can add more capacity later?

[Hesti]

Do what is needed for safety and keep some money in the kitty. Then go sailing. Once you use the boat, you will find out what really needs changing / improving / updating and you will be glad about having the funds available.


If I understand correctly, at the moment, you have 300 Ah capacity. If you have a means of recharging (wind or solar), 300 Ah can go a long way.



If you want to be off shore power for longer periods, recharging ability may have higher priority than pure battery bank capacity - it does not make a big difference if a 300 Ah or a 400 Ah battery bank is empty ...

[john61ct]

Originally Posted by ThereAndBack

So I finally bought myself another boat. She needs some work. I go about doing the things that need doing. Most recently, the dink.



I ended up with a 10ft aluminum RIB with a 15hp electric start. Do I need such a thing? Not really. I survived for years in a little portabote with a 3.5hp, but I wanted it.



Now it is time to change the batteries. The boat has 6 x GC2 batteries in it. I know I can throw 8 GC2 batteries in and have roughly 400 usable amp hours, but I'm contemplating putting lithiums in. That will of course mean changing the charge sources and all the other things.



And after that, maybe time for new solar and wind gen?



I don't have unlimited funding. Prioritization is hard. How do you reel it in and just go with "good enough" sometimes?

Where located? In the US, an investment in LFP will start paying off compared to lead, after maybe 8-10 years.

Big negative financially if they don't last 15-20, or something happens to kill the bank.

So from a strictly economic POV, a very risk move even if money is not a concern.

The question to ask, in any case, is, do I really **need** this fix/upgrade?

Costs vs benefits. . .

[ThereAndBack]

To those asking, yes, it is new battery time. The old ones are pushing 8 years and probably at 50% or less of their rated capacity now. They sag badly. It is just time.

I hear you guys on the lithium banks. I know all the pros and cons. It is more the struggle of going with the best vs just enough that I was commenting on.

[john61ct]

And your local market conditions can really make a huge difference to the economic side.

$1 / AH @12V for true deep cycling lead in the US, just is not available elsewhere afaik unless you're in China maybe.

And $7-10 / AH @12V for LFP, is I believe higher than you need to pay in EU or Oz?

[ThereAndBack]

Local market is that I can buy GC2 from Sam's for 90 bucks or t105s pretty cheap too. LFP is 1k per 100amp/hr. 12v system.

So 1k for all the batteries FLA or 4k for LFP, plus other expenses. Sure in the long run LFP is more economical assuming you don't blow the system up, but the initial price is steep.

If you go with the "best" on every system, it gets very expensive.

[Stu Jackson]

Originally Posted by ThereAndBack

>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Now it is time to change the batteries. The boat has 6 x GC2 batteries in it. I know I can throw 8 GC2 batteries in and have roughly 400 usable amp hours, but I'm contemplating putting lithiums in. That will of course mean changing the charge sources and all the other things.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

I don't have unlimited funding. Prioritization is hard. How do you reel it in and just go with "good enough" sometimes?

Could you have answered your own question?


Prioritization isn't hard. Discipline is hard.


Factors involved are Budget, Complexity and Need.


If you can't afford the more expensive batteries, budget controls.


If you can't afford the more expensive battery charging system, budget controls.


If you CAN afford either of these two, and you can't have one without the other, right?, then complexity and ROI are involved.


And in this case your "good enough" comparison doesn't seem to me to apply, since the decision making process doesn't appear to make a HUGE argument for Li over FLA, especially when you factor in the complexity of the charging system, beyond the cost altogether. FLAs work GREAT, not just "good enough" while Li might be a little bit better for the intended purpose, which is energy storage and operation.


Your boat, your choice.


But be honest about the comparisons, not emotional. Pretend you're doing this for a client.


Good luck.

[john61ct]

And $4K for that much LFP sounds way cheap to me in the US,

if you count delivery, fittings @ care infrastructure required to ensure longevity.

[Lake-Effect]

Originally Posted by ThereAndBack

I don't have unlimited funding. Prioritization is hard. How do you reel it in and just go with "good enough" sometimes?

More precious than funds is TIME. I'm a firm believer in "go now", so if one of the choices gets you out sooner... that's the choice. Especially if the effects of that choice affect the future more than the present.


I'm very interested in new battery technology... but I also appreciate that FLA batteries are still more common, cheaper, maintainable, and a bit more tolerant of abuse like the occasional overcharging. Given the 4x price difference... I'd be going with the FLA.


Maybe by the time the new FLA batteries are ready to be replaced, Li batteries will be more common and will have come down in price.

[Cheechako]

You have 6 batteries in your RIB and now want 8? What am I missing? How about 1.?

[AndyEss]

Originally Posted by Cheechako

You have 6 batteries in your RIB and now want 8? What am I missing? How about 1.?

It's one of the new, multi-purpose RIBs.
You can use it as an anchor too.

[B_Hunter45]

I have several

1. Ain't broken, don't fix it
2. Keep it as simple as possible.
3. Take the shortest path, the one that gets you to the water faster.
4. Never go to the latest and greatest. The difference in cost usually doesn't justify.

[Don C L]

Well that’s my struggle too, as I am sailing on a shoestring. I say B Hunter has it right. A lot of folks replace perfectly good things with something newer and prettier, at great expense. I just keep sailing until there is something I cannot live with for reasons of safety or it just reaches a point of cosmetic challenge that even I can’t stand. I will say, with kids banging around my boat, it is actually nice to have a strong, safe boat that is NOT so Bristol. Dad doesn’t yell so much that way.