Battery for electric outboard

[Greybeard357]

I am wondering if somebody else has done this and their experiences.
I have a 30 lb thrust electric outboard ( draws 30 amp flat out.) that I use for checking redclaw pots. Currently using a 100 ah lead acid deep cycle but it is near 2 year old so will move it on to next position and I am looking at switching to a LiFe bat instead.
Currently I use a 5.5 hp motor driving a Bosch 80 amp alt for initial recharge then a Redarc 1206 charger from batts to finish off. Now I think the genset will be ok for initial recharge but not sure how to go for finish charge. I have 300 w solar and 2 x 120ah agm batts , a 55 lt freezer runs full time off these but quite a bit of spare energy left.
Thought I might change from 12 v to 24 v sys and use a voltage controlled current limited circuit to charge LiFe or use an inverter ...

Any thoughts ?

Thanks
Merv.

[Dot]

Hi Merv and welcome to the "happy" forum I have no idea on any of your questions but some one will be along I'm sure.. Meantime why not go to the "Introduce Yourself" thread and tell us nosey people all about you and your rig if you have one that is.

[BruceS]

Please send 5kg of redclaw for answer!!!

I think we'll wait for the proper answer..... ??
Welcome aboard!!

[TigerMK1]

I'm sure Ti Terry will be along to give better advise. I know some people have fitted LIPO batteries as starters for cars/trucks and I am using LIPO 48V batteries on our bikes that push them for about 30klms. They have there own charging systems. If you check ebay/google you can get LIPO battery packs in various voltages and power. In Aus the gov limited bike power to 200W. You can get whatever size you need off ebay and they come sealed with BM and charging systems.
Cheers
Steven

[Greybeard357]

Thanks for the replies so far.
Admin , 5 kg redclaw ?? no problem but you will have to come to Emerald to collect them .http://www.ozervnews.com/forum/posting. ... ca81e1636e#

The outboard is 12 volt , was wondering how a car start battery would go (LiFepo4 ), appear to be fully cased, so less exposed joiners ect. otherwise a Winson 100 ah pack.

Merv.

[T1 Terry]

Hi Merv,
there so many possible ways of building a 12v lithium battery but as it's for a boat the very real chance of it getting wet or ending up in the water has to be added in when deciding what to recommend. In this case I think you would be better off with one of these http://www.evworks.com.au/index.php?pro ... -LP12V40AH you would need a battery charging method that would limit recharging to 13.8v to minimise the possibility of one cell over charging. The possibility is still there but in a seal battery there is no way of checking individual cell voltages or balancing the individual cells.
The ideal way to build a 12v battery is for 4 cells connected in series with a cell logger connected to monitor the individual cell voltages but this method is far from water resistant.
the other issue is size, the smallest individual Winston cells that are available off the shelf in Aust are 60Ah, the most common is 100Ah, a lot bigger than what you need so they would be a lot more expensive, the 100Ah 4 cell battery even with just a logger would be around the $600 mark, hard to justify for a boat battery used every so often that doesn't really need the 100Ah of capacity, then add the risk of the whole thing going in the drink and killing the cell logger. That bit is only $28 but all the cables and connections would need to be stripped out and cleaned to stop corrosion etc.
The battery would last a lot longer and you would know when a cell was fully charged and if a slight balancing was needed and a warning that a cell as getting deeply discharged with the 4 cell battery and a logger but I'm not sure it justifies the added cost.

T1 Terry

[Greybeard357]

Terry the average run time would be 30 - 40 minutes but could be more occasionaly so I wouldn't be comfortable with a 40 ah batt. I was looking at the LP 12v 90 but maybe the 6o ah would be enough.
I don't use the petrol o/b if I can help,. elec is so much easier to use.
If I was to use an inverter then battery charger is there any special requirements needed ?

Thanks
Merv.

[T1 Terry]

How long run time do you get with the 100Ah lead acid you are using at the moment? The 40Ah lithium would give you the same run time as the 100ah lead acid, the 60Ah would do it with power to spare.
All you need is a battery charger that only charges to 13.8v, it can be solar, a DC To DC or a mains charger. EV Power http://ev-power.com.au/webstore/index.p ... cells.html has 40Ah and 70Ah cells so you could build up a 4 cell battery and then use a cell logger to beter monitor the cell voltages, cost a bit more but you would know just how the cells were travelling when you were recharging them.

[homeless]

I cheated as my boat battery uses the same cells as my house and crank batteries in the bus so in the event one cell DID fail I have 4 spare cells.
My battery also has been used for my 12v air compressor (goes like the clappers and pumped my tyre up a lot faster than the AGM's did ) and also it is used for the 18v chain saw, so it has multiple uses and also is my spares if needed. Cant do that with the built up models.
Terry's thoughts on the need to learn how to charge and manage the battery may be not your thing so then the ready made is perhaps the best way.
It is great to be able to carry a light battery around but have the power of 200AH. My battery is in a old battery box with a few other bits .
Regards
Brian

[BobnBev]

Hi People, A good subject, The son inlaw has a fresh water fish farm and they were setting it up a some months back. They normaly use elect.OB to stop oil ect . getting in the water, as you would.. Now some time back I picked up some 5, 40 amph second hand LiFePo4 LFP batterys from e---bay . The son in law got 3 , 2 went in the back of the ute to run the fridge. The 3rd was a spare. They did some work in the dam and used 2 elect OBM. 1 had a 100 amph AGM, the other a LiFePo4 40 amph SH battery. and by the end of the morning( a good 3.5 hours) they were charging the AGM, but the 40 amph LiFePo4 was still going strong. It went better than the agm by a big way. As in speed and time used..And a quater of the weight...
They still talk about it.....
Bob n Bev...