Lithium battery for cd25 day sailer?

[Kilgore]

Has anyone tried one of these? They are getting cheap, small and plentiful. My lead-acid is due for replacement and I'm considering something easier to haul on/off the boat. Mine only powers radio, instruments and rarely the LED running and cabin lights. The current battery is topped off by the Tohatsu SailPro and a small 12" square solar panel. Lithium batteries need special controllers to avoid overcharge fires, correct?

[Astronomertoo]

I would be curious as to what prices you are seeing. I am used to buying the low priced golf cart batteries for all my boats, and RVs which are very reasonably priced and are durable. I saw a new Li 12V 100AH battery the other day advertised for $1000. I was shocked.
I am normally happy with lead acid batteries. Just make sure you mount them in a boat so the battery long axis is oriented port-starbd which puts the individual cells longwise bow to stern, and use a catchment box for spilled acid just in case. If you mount the batteries long wise bow to stern they will have more chances to spill when you accidentally or intentionally put the rail in the water. BTW, sealed batteries would not leak. Why does it matter?

See https://forums.sailboatowners.com/index ... es.148709/

My boat is still apart after finding too many things in poor condition, and I am slow. When I bought my boat it had dual batteries mounted incorrectly, and the lower keel bilge was very acidic. It took lots of sodium bicarbonate and a lot of flushing with a hose and a new drain, to neutralize it. The entire bilge will still require scrubbing with a long handled stiff brush to clean the brown lead precipitated stain from the acid and some loose lead ballast pigs found in the bottom of the keel, before painting with gray bilge coat.
Bob C

[Terry]

Has anyone tried one of these? They are getting cheap, small and plentiful. My lead-acid is due for replacement and I'm considering something easier to haul on/off the boat. Mine only powers radio, instruments and rarely the LED running and cabin lights. The current battery is topped off by the Tohatsu SailPro and a small 12" square solar panel. Lithium batteries need special controllers to avoid overcharge fires, correct?

A lithium ion is an option if you want to take it home for a charge it, as it is small and light. I checked the price on Amazon for a 10 amp l-ion, and it was $99. There are some that are made for motorcycles. I didn't see the amp/hr capacity or the price.

When my lead acid bat died, I didn't immediately replace it, just ran without power. I have a marine handheld and a Garmin handheld. It worked fine. Eventually I installed an Optima AGM, which cost me about $140 through CostCo ($190 at Amazon). It fits in the same area as the lead acid, but doesn't require a battery box or venting. The SailPro will recharge it directly, without controller. It is 55 amp/hrs.

One consideration, and a major one in my opinion, is the overall power consumption expected, worst case. For me, I want enough power for lights, marine radio, and ham radio. And I want that for more than one day. Eventually, I will end up with four Optima or equivalent batteries and a better solar panel system to maintain charge.

The thing to do would be to calculate your power requirements and go from there. You'd be able to take out your solar panel. Nice and simple.

Another consideration may be a Gell Cell, like the ones used in home security systems and small uninterruptible power supplies. I've used those before. They are light weight and very cheap. After a few years, toss it, and buy another. Again, it all depends on anticipated, worse-case consumption.

All the Best. . .

[Kilgore]

The batteries I was looking at, that are now used in sports cars to shave weight, are in the 100 watt hour range for around 200 bucks.