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> I'm surprised boats are already moving to lithium. When the alternative is a bank of lead-acid batteries with effectively ~50% usable capacity and poor charg

> I'm surprised boats are already moving to lithium. When the alternative is a bank of lead-acid batteries with effectively ~50% usable capacity and poor charge efficiency, at least for cruisers effectively living at sea off solar power, it's not surprising at all.

kragen 7y ago
The lead-acid batteries still cost a lot less per joule of capacity than the lithium batteries do. They just weigh more. Or maybe charge efficiency is the reason?
- newnewpdro 7y ago
  Space tends to be at a premium for cruisers, and modern cruisers are increasingly embracing electricity for powering everything. Charge efficiency is a big one, but it's also just maximizing energy capacity in the available volume.
gnaritas 7y ago
Lead-acid is still better, it's 1/10 the cost for equivalent usable amp-hours. Most boaters use deep cycle golf cart batteries, they're produced at such scale that they're cheap as hell. Lithium is a waste of money and dangerous to boot. They only make sense if you're extremely space limited, which most bigger boats aren't.
- darksaints 7y ago
  Most marine lithium batteries are LiFePO, not lithium ion. They're far more stable and safe to have on a boat. Compared to lead acid, they have better charge efficiency, deeper cycles, longer lifespans, higher energy density and specific capacity. Furthermore, I've never found lead acid batteries that come close to 1/10th the price...1/4 is more like it.
  - gnaritas 7y ago
    Fair point on the LiFePO, but none of those other things really matter as they're easily made up for by a larger bank, what matters is the cost per amp/hour and lithium isn't remotely there yet. The exact fraction varies, but lithium isn't going to touch some Costco golf cart batteries at a $100 a pop. You can buy an entire house bank for the cost of 1 lithium LiFePO battery (nearly 1k on Amazon). Unless you just like wasting money, deep-cycle lead-acid is a far better choice.
kragen 7y ago
WTF! gnaritas's comment has been [dead]ed. This site is turning into a fucking shithole. Here's what he said: "Lead-acid is still better, it's 1/10 the cost for equivalent usable amp-hours. Most boaters use deep cycle golf cart batteries, they're produced at such scale that they're cheap as hell. Lithium is a waste of money and dangerous to boot. They only make sense if you're extremely space limited, which most bigger boats aren't." Edit: apparently enough people vouched for the comment, it's back from the dead. But this definitely should not be happening to people like gnaritas who have devoted so much time and effort to making HN better.

kragen 7y ago

The lead-acid batteries still cost a lot less per joule of capacity than the lithium batteries do. They just weigh more. Or maybe charge efficiency is the reason?

newnewpdro 7y ago
Space tends to be at a premium for cruisers, and modern cruisers are increasingly embracing electricity for powering everything. Charge efficiency is a big one, but it's also just maximizing energy capacity in the available volume.

gnaritas 7y ago

Lead-acid is still better, it's 1/10 the cost for equivalent usable amp-hours. Most boaters use deep cycle golf cart batteries, they're produced at such scale that they're cheap as hell. Lithium is a waste of money and dangerous to boot. They only make sense if you're extremely space limited, which most bigger boats aren't.

darksaints 7y ago
Most marine lithium batteries are LiFePO, not lithium ion. They're far more stable and safe to have on a boat. Compared to lead acid, they have better charge efficiency, deeper cycles, longer lifespans, higher energy density and specific capacity. Furthermore, I've never found lead acid batteries that come close to 1/10th the price...1/4 is more like it.
- gnaritas 7y ago
  Fair point on the LiFePO, but none of those other things really matter as they're easily made up for by a larger bank, what matters is the cost per amp/hour and lithium isn't remotely there yet. The exact fraction varies, but lithium isn't going to touch some Costco golf cart batteries at a $100 a pop. You can buy an entire house bank for the cost of 1 lithium LiFePO battery (nearly 1k on Amazon). Unless you just like wasting money, deep-cycle lead-acid is a far better choice.

kragen 7y ago

WTF! gnaritas's comment has been [dead]ed. This site is turning into a fucking shithole. Here's what he said: "Lead-acid is still better, it's 1/10 the cost for equivalent usable amp-hours. Most boaters use deep cycle golf cart batteries, they're produced at such scale that they're cheap as hell. Lithium is a waste of money and dangerous to boot. They only make sense if you're extremely space limited, which most bigger boats aren't." Edit: apparently enough people vouched for the comment, it's back from the dead. But this definitely should not be happening to people like gnaritas who have devoted so much time and effort to making HN better.