Re: [electricboats] [Electric Boats] Battery Bank Charging >

Haven't had much of a change to go full throttle yet except pier side. Previous owner passed away and the boat was for sale about 4.5years. I've been going through it and tending to a hit list of stuff. With that being said I have gone full throttle pier side and rocked the boats next dock over. I did see /hear some cavitation. Not sure if it's effected by being tied up and boat not moving. FYI I have a 13x14rh prop. It's shot, replacing with 14x12rh. No reasoning behind different sizing other than it in new old stock and cheap..🥴

John

On Sat, Jan 11, 2020 at 4:01 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.