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sailorbryant · 27-05-2022, 15:36

Switched house batteries to lithium

Thought I would give a report on getting new lithium batteries for my sailboat. We have a Hunter 460. My existing batteries were six Five year old Trojan T-105 six volt golf cart batteries for a house bank of 600 AH. My existing inverter/charger was a Xantrex Freedom 2000. I had two existing 235Watt solar panels with TriStar 45A solar controller.

I installed the following in January 2022 before cruising to the Bahamas for two months.

1. Two Jita 300 AH lifep04 batteries
2. Magnum 3000 watt inverter/charger
3. Renogy 50 amp DC-DC charger with MPPT solar controller
4. Renogy battery monitor with 500A shunt
5. Two 300A power buss bars for battery installation.
6. New cables as needed
7. 12v trolling motor breakers as needed
8. I added two additional 200 watt solar panels.

I installed the batteries per manufacturer instructions. Also after installation I discharged each battery to 11V per manufacturer instructions and then charged them to 14.7V per manufacturer. The capacity recorded by the battery monitor was 312AH for one battery and 313AH for the other. The voltage comparison between batteries from the manufacturer before discharge and after resting the batteries were virtually identical which indicated they were balanced.

I am very happy with the new installation. The batteries charged very quickly and it was nice that the voltage never dropped very much during use. During our two months in the Bahamas our electrical consumption consisted of:
1. 12V freezer and refrigerator compressors
2. 30 gal per hour watermaker for two hours every 4-5 days
3. Lights, charging phones, computers, toothbrushes, razor and batteries for tools.
4. Electric kettle, Instapot and Ninja cooker. We had always used propane in the past for cooking and found out we had plenty of battery power to use electric with the new batteries. We used almost no propane in two months- less than 10% of one 10lb tank.
5. Electric ice maker we run for about a half day every two to three days. We really like ice in our sundowners.

We did not have to run the generator for the entire time we were in the Bahamas. The solar panels and batteries supplied all of our power. Power from motoring was pretty inconsequential as we only used about 10-15 gal of diesel while we were there.

In summary the batteries performed flawlessly and exceeded our expectations. The lowest we discharged them to was 33% after making a lot of water one day and having the Instapot on most of the day. The next day was sunny and they came back up to 75%. The next day after that was sunny also and they came back up to 100%.

**GordMay** · 28-05-2022, 02:16

Greetings and welcome aboard the CF, Bryant.
Thanx for the report.

PaulCrawhorn · 28-05-2022, 06:42

I could not find anyone having done even a basic cap test on the Jita, much less a teardown on what sort of cells they used.

BMS - C-rate limitations? Protection just cuts power off, or allows for signaling a relay or external controls?

Any feedback on per-group voltages to track imbalance issues?

Setpoints, "start balance" voltage, the "bleeding" balancing current rate in mA.

Adjustability?

Temperature based cutoff?

Is there an internal heating pad?

Bill O · 28-05-2022, 10:29

Bryant,
Thanks for the report, it seems encouraging to finally switch to lithium.

What water maker are you running?

Bill O · 28-05-2022, 10:39

Paul,
Not to hijack the thread, but you obviously know much more than I do on lithium. Any issues w/these 300ah bats?
https://www.amazon.com/dp/B08K7HZ6KZ..._dp_it_im&th=1

Will Prowse

Will Prowse tore them down and seemed ok.

(We aren't planning any high lat trips so don't think we need internal heating)

donradcliffe · 28-05-2022, 11:02

What was the maximum load current and charging current ? I looked on Amazon, and in February the seller said that a 200 amp BMS was an extra cost option.

Seriously Slow · 28-05-2022, 20:35

Thanks for the report. I just bought one of those batteries for an RV. and have been happy so far. Interesting that you did the deep discharge and charge to 100% routine as I was told by a rep that it wasn't necessary. Just fully charge it and use it. It seems they can't decide?
200 amp max discharge according to specs.

Scubaseas · 29-05-2022, 02:10

Thanks for the report. The 900watts solar surely helps. Your experience mirrors mine after switching to lithium. Very happy with the performance and quick charge times. I just need more solar!

sailorbryant · 29-05-2022, 17:12

The max current discharge per spec sheet I received with batteries was 200 amps. I have two in parallel which gives me 400 amps which is more than than enough for my 3000 watt inverter. I think the max draw I remember was around 2500 watts when I was using the inverter to power my 6 gal electric hot water heater. I only ran the hot water heater for about 30 minutes and there was no problem. The voltage on the batteries dropped to about 12.6 to 12.8 volts while heater was running.

wholybee · 29-05-2022, 17:27

Awesome. LiFePO4 is a gamechanger, and there are many options for install. What I learned from mine, and you have proven also, is that you don't need the expensive high end BMS with relays and CANBUS connections to everything. They are truly (if installed correctly) and install it and forget it piece of kit.

And because they charge so fast from solar, there is less need for other charging sources, and you can use all the electric gizmos.

Congrats on your sailing season.