Re: [electricboats] [Electric Boats] Battery Bank Charging >> How to run "hybrid" with a generator?

nope-  for LiFePo4 batteries it is recommended to store them at 50%.  I've done both ways over the years with my CALB 180AH  (20 cells, 64V) either near full charge or about half charge and never see any difference on startup in the spring. Voltage essentially identical to how I leave it in the fall.

That's the beautiful thing with electric motor and lithium.  Turn off in the fall, pull battery cable, walk away-  attach battery cable in the spring and motor to the slip. Just like 7 months of cold northern winter never happened. I've not seen any self-discharge whatsoever through the winter.

Also, I have run perfectly in "hybrid" fashion by running my 2kW generator connected to shorepower inlet.  I can go any speed- at low speed will also charge battery ; at full speed will have some of the energy from the generator and the rest from the battery. Or I can pick a speed to show zero charge/discharge for the battery- this was about 4 knots

George Ojdrovich

Tartan 34C with 5kW and 11.5kwH battery

On Jan 11, 2020, at 5:42 PM, Bob Jennings <heatnh@gmail.com> wrote:

Harley, not sure where you're located  but leaving batteries @ 50% SOC to sit over the "winter" will kill them. 50% SOC, they are subject to freezing. Just saying...

Bob

On Sat, Jan 11, 2020, 7:01 PM Harley Clark <clarkharley37@gmail.com> wrote:

Helpful report. 

I have a 10kw drive in my 1978 Tartan 34 with a 100 ah LIFEPO4 battery bank.

I wanted to extend my range so I bought a 2kw generator but have not used it , yet.

Just for the record, I have an Orion Jr. BMS with switching relays to limit charging and discharge.

This winter I am intentionally leaving the battery bank sit at about 50% charge to extend the battery life.

I have noticed that I can spin the propellor enough so I think it begins to cavitate. Have you experienced

On Fri, Jan 10, 2020 at 6:33 PM John Montgomery via Groups.Io <gotz2sail=yahoo.com@groups.io> wrote:

Hi,

I have a 5kw motor, 240ah bank at 48v. The charger I had at the time output 15a. I knew I was going to upgrade to a 25a charger. Sidenote, USBatttery eng. recommend a charger that can do 20% or slightly more of your amp hours. So the 15a was to small. 

Anyway, I ran the math. 48v at 25a is 1200w. 1200w at 120v is 10a. I found a generator at home Depot that ran 1600w continuous with an RV connector. I ran generator connected to my shore power connection. Charger ran 120v to 48v and then the buss. 

I clamped the battery leads and saw 0a, 15a from charger . Throttled up to say 20a, I'd see 15a from charger then 5a out of bank. Tada motor sailing/hybrid gen.

Kind of a sloppy set up but it worked. To do like your saying about gen to motor you'd need some kind of ac-dc drive. 120v in and 48v out with enough amp out to push you along. I'm powering a 30' Newport sailboat, 20a gets me going assuming I don't have a headwind ect. Think about what your pushing. Is 20a enough? If so you'll need something that can do 20a continous with spurts above that for a minute.

Hope I wasn't to confusing.