Upgrad AGM Battery’s to lithium instead of the solar route

[Jim from New York]

Has anybody upgraded to lithium and found it adds that little bit more time on anchor and not needed to go the solar route? I usually stay two days on anchor without starting the motor and of course, my battery drains to a point where the refrigerator won’t operate. If lithium has worked for anybody in this situation please chime in would appreciate your input.. It’s a lighter set up and about the same cost of a good solar system. I think my 2018 23 would have the right charger needed but I would need to check. Thanks for any input Jim

[thataway]

I did that in a slightly different way--in that I added the LiFePO4 (2-100 amp batteries) to carry the load of my freezer chest and the Refrigerator chest. This will carry this load for at least two days. That left the FLA house batteries with very little drain--and thus gave me up to 3 days with out battery charging. That is pushing the envelope a bit. But possible. The other house load (LED Anchor Light, and LED cabin lights) are minimal, and plenty of power for that--even enough to charge the Torqeedo if necessary. Recharged with a full days run with the engine. Off this same system, I had a Victron multiplus 2000 watt inverter to run the induction burner and the microwave. The victon inverter also has an 85 amp battery charger and mains power boost of 50 amps if necessary to sync with mains power for low voltage, low amperage at a dock.

I have never had solar on the boats I have owned. For my house essentials I built a 600 amp hour battery bank (12 volt) and 1200 watts of Solar panel to run deep freeze and refrigerator, as well as LED secondary house system (Has 3000 watt PSW inverter).

[Jim from New York]

I’ll be pricing out three batteries and checking the battery charger to see it handles lithium. I would like to keep the cabin top clear of solar and use for storing kayaks and such. If I do it I’ll let you know how it worked out
Jim

[thataway]

With li batteries. Be sure and follow all of the instructions, and ABYC rules. Essential to have good fuses, make sure that the wires are short as possible, proper gauge, and well insulated. Have a good appropriate battery switch near the battery. Have good monitoring systems.

[Marco Flamingo]

I went with lithium on my trawler. Get the ones with Bluetooth so that you can really see what they are doing. I went with 4 280AH batteries (bigger boat, bigger battery bank). It was right before the recent tariff increase, so a bargain. An extra battery is an extra day at anchor.

Fusing is an issue because of the amount they can discharge in a short circuit. You probably should have a MRBF on each terminal for 100Ah batteries. Larger ones need more complex fusing because of the need for higher AIC (amperage interupt capacity).

LFP batteries can be placed on their sides, stacked, etc. in ways that lead can't be. Plus lighter and easier to place in remote places. The initial cost of an extra battery and cables will pay out if you own the boat for any length of time. If you use them only as house and charge with shore power, that simplifies a lot.

Don't think that you have to have a special LFP charger. An LFP charger might be more convenient, but isn't always necessary. Charge LFP and don't float. A "full" charge isn't always required and doesn't shorten battery life. With Bluetooth, you can hook up your old charger and simply unplug it when the batteries are at 95%. Don't need no stinkin' float.

[gulfcoast john]

Hi Jim,

We had enough clear roof space that a $149 100W Renogy panel, Victron MPPT controller and Blue Seas circuit breaker gives us unlimited nights for under $250 grand total if there is some sun during the daytime. The typical marine fridge uses no 12v power (other than the LED door light) unless the Danfoss compressor is running. We keep the thermostat (marked 0-5) at 3 during the day, but after the last fridge door closes at night, we dial it back to 1 with full oversize ice cube trays for temp ballast, which cuts the compressor usage by about 50% without the ice melting. Defrost when the icebox gets ¼” of ice frost to also improve efficiency.

If the lithium option turns out to be more expensive than you want, you could consider a quiet inverter 110v generator like the Honda 2300 (which can power a 15K rooftop AC and all other appliances on board) or a used 2000iu. The $599 Firman 2000 appears to be a cheap knockoff, but surprisingly gets a very good Consumer Reports review. I’d get a Harbor Freight extension for the 90 day warranty, a couple of high quality CO alarms and never run it at night or when asleep. Downside is the space required.

https://www.harborfreight.com/2000-watt-super-quiet-inverter-generator-with-co-secure-technology-epa-71343.html

Best of luck in finding a solution that works great for you!

John

[Jim from New York]

Looks like im staying with original plan of using solar to add a bit more time on the hook. It will be a fun interesting project thinking of starting with 100 watt rigid mounted panel on cabin top making sure the controller will handle a second panel if need more. The lithium batteries would be nice but ends up much more costly, thought of changing refrigerator that won’t solve much ether. So that’s the plan. Thanks for all the information

A bit of information for those looking for a system I found is renogy has a Bluetooth module for checking the battery condition, for safety ect.
But I found a very interesting complaint . It only allows access to the app on your phone with Internet connection which provides the link( no Internet no app visualization)
I could be offshore with no internet access. It is mind-numbingly dumb that thee app that requires login
Just saying

[thataway]

The Victron smart shunt and other products do not need internet--blue tooth should not need internet connection.

Any of the small refrigerators use a compressor. The Fuji swing motor uses a little less power than the Danfoss compressors, with the rest use.

It was our observation at Lake Powell 200 watts of solar panels were necessary to keep up with the refrigerators.

[kennharriet]

I’ll have more to report soon as we are on day one headed to Skagway from Idaho. This is the maiden road trip/voyage with 2 100ah Li batteries, 200w of portable panel and 20 amp DC-DC charger. We carry an Alaska series dingy so did not want rigid panels. The folding portable panels slide under the stainless dingy rack securely and are available for charging once the dingy is deployed. Our Engel freezer is the primary load along with a Wallas 1300 heater, Starlink mini and other electronics.