Reply
 
Thread Tools Search this Thread Display Modes
 
Old 10-25-2019, 05:30 PM   #41
Guru
 
TDunn's Avatar
 
City: Maine Coast
Country: USA
Vessel Name: Tortuga
Vessel Model: Nunes Brothers Raised Deck Cruiser
Join Date: Feb 2015
Posts: 877
One consideration for lithium iron phosphate batteries is charging with your alternator. Lithium batteries can accept very high charge currents. If the batteries are low they can and will pull your alternator up to 100% output unless you have an external regulator that lets you limit charging current. This can be an issue if the engine speed is low since the alternator will not be adequately cooled and can burn up. The solution is simple - install an alternator with a sophisticated external regulator that can limit current, or use a DC to DC converter fed by the alternator for the charging. The converter will limit charging amps to a safe level for your standard alternator. Victron has a new video in this issue which is worth watching. Suitable converters are sold as DC to DC battery chargers.
__________________
Advertisement

TDunn is offline   Reply With Quote
Old 10-25-2019, 06:36 PM   #42
Grand Vizier
 
Delfin's Avatar
 
Join Date: Jan 2010
Posts: 3,442
Quote:
Originally Posted by TDunn View Post
One consideration for lithium iron phosphate batteries is charging with your alternator. Lithium batteries can accept very high charge currents. If the batteries are low they can and will pull your alternator up to 100% output unless you have an external regulator that lets you limit charging current. This can be an issue if the engine speed is low since the alternator will not be adequately cooled and can burn up. The solution is simple - install an alternator with a sophisticated external regulator that can limit current, or use a DC to DC converter fed by the alternator for the charging. The converter will limit charging amps to a safe level for your standard alternator. Victron has a new video in this issue which is worth watching. Suitable converters are sold as DC to DC battery chargers.
They pull the same amount of current through about 98% of their capacity, but your point is well taken. A Balmar MC6xx regulator allows you to derate the output of the alternator. Mine is set to around 70% of maximum.
__________________

Delfin is offline   Reply With Quote
Old 10-26-2019, 12:39 AM   #43
DDW
Guru
 
City: San Francisco
Country: USA
Join Date: Apr 2018
Posts: 990
If I were changing over and particularly if buying a new external regulator for the alternator, I'd heavily consider a Wakespeed 500 instead of the Balmar. The Balmar 6xx can't really tell when the batteries are full, it just guesses and is easily confused. The Wakespeed is the next generation as it can measure current, not just voltage.
DDW is online now   Reply With Quote
Old 10-26-2019, 09:31 AM   #44
Grand Vizier
 
Delfin's Avatar
 
Join Date: Jan 2010
Posts: 3,442
Quote:
Originally Posted by DDW View Post
If I were changing over and particularly if buying a new external regulator for the alternator, I'd heavily consider a Wakespeed 500 instead of the Balmar. The Balmar 6xx can't really tell when the batteries are full, it just guesses and is easily confused. The Wakespeed is the next generation as it can measure current, not just voltage.
There's a lot to like about the Wakespeed, except for one fairly important lack of functionality. Unless I'm misreading the manual, because you use dip switches with set profiles, you have no control over bulk voltage. If the want something other than 13.8/27.6 v, you're out of luck. This regime is fine, most of the time, but if you don't have the ability to ramp that voltage up to the level balancing circuitry on the BMS kicks in, you may see a decline in capacity due to memory effects.
Delfin is offline   Reply With Quote
Old 10-26-2019, 10:25 AM   #45
DDW
Guru
 
City: San Francisco
Country: USA
Join Date: Apr 2018
Posts: 990
Dip switches only set the rough functionality. You need to hook the Wakespeed 500 up to your laptop, then you can set just about everything you could imagine and a few things you didn't. A large superset of the Balmar 6xx. There'd be no point (well not much point) in paying for the 500 without accessing that functionality. In addition, the Wakespeed will communicate directly with some BMS units over Canbus. The Wakespeed 100 is more rudimentary, and less capable than the Balmar IMO.
DDW is online now   Reply With Quote
Old 10-26-2019, 10:43 AM   #46
Grand Vizier
 
Delfin's Avatar
 
Join Date: Jan 2010
Posts: 3,442
Quote:
Originally Posted by DDW View Post
Dip switches only set the rough functionality. You need to hook the Wakespeed 500 up to your laptop, then you can set just about everything you could imagine and a few things you didn't. A large superset of the Balmar 6xx. There'd be no point (well not much point) in paying for the 500 without accessing that functionality. In addition, the Wakespeed will communicate directly with some BMS units over Canbus. The Wakespeed 100 is more rudimentary, and less capable than the Balmar IMO.
Ah, thank you. I missed that external control functionality. Does look like a very good unit.
__________________
Delfin
"Dad always thought laughter was the best medicine, which I guess is why several of us died of tuberculosis." - Jack Handy
Delfin is offline   Reply With Quote
Old 10-26-2019, 11:05 AM   #47
DDW
Guru
 
City: San Francisco
Country: USA
Join Date: Apr 2018
Posts: 990
And, they are right over there in Oak Harbor if you have a question. Balmar has been bought and moved to Alabama, anybody that knows how the 6xx works (intimately) has left the company.
DDW is online now   Reply With Quote
Old 10-26-2019, 07:42 PM   #48
Grand Vizier
 
Delfin's Avatar
 
Join Date: Jan 2010
Posts: 3,442
Quote:
Originally Posted by DDW View Post
And, they are right over there in Oak Harbor if you have a question. Balmar has been bought and moved to Alabama, anybody that knows how the 6xx works (intimately) has left the company.
Not everyone. Tom Postieri (sp?) is still in Arlington and always helpful, and I think Chris Witzgel also knows his product.
Delfin is offline   Reply With Quote
Old 10-26-2019, 07:46 PM   #49
Senior Member
 
stevemitchell's Avatar
 
City: Seattle
Country: USA
Vessel Name: Rendezvous
Vessel Model: Ocean Alexander 420 Sundeck
Join Date: Sep 2018
Posts: 315
I've got a draft article I hope to publish in the next week or two on a 6 month use cycle of the Wakespeed WS-500 regulator on dual engines along with my LiFePO4 bank + higher amperage alternators.

So far I can say I am very impressed with them, and have not found a better system for charging LiFePO4 or higher amperage current batteries. They are infinitely configurable (both a blessing and a curse) and use CANbus to communicate between eachother to ensure they are both working equally well. That and the fact that they also use a shunt to monitor the actual amperage going in/out of the bank make this a pretty similar charging system to an actual AC charger/inverter.
__________________
Steve Mitchell - Editor SeaBits.com
m/v Rendezvous
1988 Ocean Alexander 420 Sundeck
stevemitchell is offline   Reply With Quote
Old 10-29-2019, 04:41 PM   #50
Veteran Member
 
DCDC's Avatar
 
City: New Orleans
Country: USA
Vessel Name: Stella
Vessel Model: Seaton 56
Join Date: Sep 2017
Posts: 81
Thanks for all the input and ideas.
DCDC is offline   Reply With Quote
Old 10-30-2019, 10:19 AM   #51
Senior Member
 
RickyD's Avatar
 
City: Long Beach, CA
Country: United States
Vessel Name: Aquarius
Vessel Model: Californian 55 CPMY
Join Date: May 2018
Posts: 141
[QUOTE=twistedtree;812749]Something in the 1400ah @ 24V range. It's probably serious overkill, but without a solid understanding of the electric loads, I'd rather err on the side of too much rather than too little. And that's nameplate rating, so figure 80-90% of that is usable.


Part of the uncertainty is because I haven't finalized what batteries I'm going to use, and they come if different quanta of capacity. Plus I'm leaning towards a redundant setup with two banks, so the capacity steps are pairs of batteries.. Several vendors sell ~300Ah batteries, so a bank of 4 would be 1200 ah, and 6 would jump up to 1800ah.[/QUOTE

What about cranking power with LiPo? I would like to replace my 4 LA 8Ds and pick up more amp hours. With my two refrigerator freezers, one of which draws 6.5 amps at 120v so I guess 70 amps at 12v through the inverter, I draw down my bank overnight and have to run the genset for hours to charge back up in the morning and again in the evening. My current set up is the start battery and two other 8Ds are the house bank, and the other 8D is the start for the port engine. This way I always have a start battery. I also have a battery combiner. Can I use LiPo for starting my 3208 Cats?
__________________
Aquarius 1991 Californian 55 CPMY Long Beach CA
RickyD is offline   Reply With Quote
Old 11-01-2019, 05:58 AM   #52
FF
Guru
 
FF's Avatar
 
Join Date: Oct 2007
Posts: 19,908
"With my two refrigerator freezers, one of which draws 6.5 amps at 120v so I guess 70 amps at 12v through the inverter,"


Have you contemplated installing more efficient DC reefers?
FF is offline   Reply With Quote
Old 11-01-2019, 07:19 AM   #53
Guru
 
twistedtree's Avatar
 
City: Gloucester, MA
Country: USA
Join Date: Jan 2013
Posts: 5,137
Using LFP as a start battery might be problematic, so it should be carefully researched.

The good news is that they can deliver high current, but you don’t want to do it for anything other than a short burst. But that matches the load for starting an engine- usually. Typical max draw limits are 3C to 5C. You’d have to check your starter specs, but I think 800-1000A draw could be expected. At 3-5C, you are looking at a 200-300ah battery.

That said, most drop ins have built in current limiting and will disconnect if current exceeds specs. The catch is that those specs are usually based on continuous current, not short term burst current. So the disconnect is likely at around 1C, so 200A on a 200ah battery. With this, there is a distinct risk that the battery will shut down when you start cranking.
__________________

__________________
www.MVTanglewood.com
twistedtree is online now   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 12:14 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012
×