Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rating: Thread Rating: 33 votes, 4.82 average. Display Modes
Old 21-01-2013, 18:21   #1321
Registered User
 
deckofficer's Avatar

Join Date: Feb 2011
Location: Northern and Southern California
Boat: too many
Posts: 4,197
Images: 4
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

I goofed. New power supplies and chargers are using switching instead of heavy transformers. My charger only weighs 8 lbs, rated at 1200 watts. I have a switching power supply for my HF SSB and at 30 amps only weighs maybe 5 lbs. I also have a 75 amp 12 VDC supply for the HF amp, it uses a transformer and weighs 30 lbs.
__________________

__________________
Bob
USCG Unlimited Tonnage Open Ocean (CMA)
http://tbuckets.lefora.com/
deckofficer is offline   Reply With Quote
Old 21-01-2013, 18:25   #1322
Registered User
 
deckofficer's Avatar

Join Date: Feb 2011
Location: Northern and Southern California
Boat: too many
Posts: 4,197
Images: 4
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Quote:
Originally Posted by diugo View Post
I like the idea of a good crimp, followed by tight heat shrink to keep moisture out. Soldering large cables is a lot of extra work!
I'm changing my mind after soldering up my parallel jumpers, and will finally embrace crimping over soldering and pony up the $250 for a crimper.
__________________

__________________
Bob
USCG Unlimited Tonnage Open Ocean (CMA)
http://tbuckets.lefora.com/
deckofficer is offline   Reply With Quote
Old 21-01-2013, 18:28   #1323
Registered User
 
diugo's Avatar

Join Date: Dec 2012
Location: Yuma, AZ
Boat: USS Asymptote
Posts: 261
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Bob, I got my cables crimped from some guy named genuinedealz on eBay, you buy the cable and lugs from his store, and for a dollar he will crimp the cable. No need to buy a $250 crimper.
__________________
diugo is offline   Reply With Quote
Old 21-01-2013, 18:38   #1324
Registered User
 
deckofficer's Avatar

Join Date: Feb 2011
Location: Northern and Southern California
Boat: too many
Posts: 4,197
Images: 4
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Quote:
Originally Posted by diugo View Post
Bob, I got my cables crimped from some guy named genuinedealz on eBay, you buy the cable and lugs from his store, and for a dollar he will crimp the cable. No need to buy a $250 crimper.
That is a good reference, thanks. I've had crimping done for me on some of my EV projects, but for the boat I'll buy them. Nice way to warm up a new anchorage to your arrival, when someone puts the call out, having cables that have fried out of their lugs, your equipped to help if you have crimpers. Just a good tool to have onboard with so many cruisers having high current demands from their inverters in our nasty, salty world.
__________________
Bob
USCG Unlimited Tonnage Open Ocean (CMA)
http://tbuckets.lefora.com/
deckofficer is offline   Reply With Quote
Old 22-01-2013, 01:16   #1325
Registered User
 
catakate's Avatar

Join Date: Jan 2013
Location: Bucharest
Boat: Anderson 22
Posts: 133
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Quote:
Originally Posted by deckofficer View Post
Nice way to warm up a new anchorage to your arrival, when someone puts the call out, having cables that have fried out of their lugs, your equipped to help if you have crimpers. Just a good tool to have onboard with so many cruisers having high current demands from their inverters in our nasty, salty world.
Yet another good idea for when I'll hit the Med.
__________________
Been on the mountain's top, now is time for sea level!
God created the world in 6 days and then gave us Bill Gates to teach us how to cope with that!
catakate is offline   Reply With Quote
Old 22-01-2013, 05:37   #1326
Registered User
 
ebaugh's Avatar

Join Date: Dec 2011
Location: On the boat
Boat: DeFever 44
Posts: 525
Awhile back we we looking at how to separate charging and discharging paths...especially inverter chargers. Anyone see a problem with this circuit?
Attached Thumbnails
Click image for larger version

Name:	image-671344861.jpg
Views:	64
Size:	42.3 KB
ID:	53302  
__________________
ebaugh is offline   Reply With Quote
Old 22-01-2013, 05:48   #1327
mrm
Registered User

Join Date: Feb 2011
Location: Poland, EU
Boat: crew on Bavaria 38 Cruiser
Posts: 552
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

What diode current ratings you propose?

Say, a charge solenoid opens and you use windlass or a bow thruster...
__________________
mrm is offline   Reply With Quote
Old 22-01-2013, 05:56   #1328
Registered User
 
ebaugh's Avatar

Join Date: Dec 2011
Location: On the boat
Boat: DeFever 44
Posts: 525
They would have to be battery isolator sized for the largest of your charge/discharge current expectations.
__________________
ebaugh is offline   Reply With Quote
Old 22-01-2013, 06:19   #1329
Registered User
 
diugo's Avatar

Join Date: Dec 2012
Location: Yuma, AZ
Boat: USS Asymptote
Posts: 261
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Quote:
Originally Posted by ebaugh View Post
Awhile back we we looking at how to separate charging and discharging paths...especially inverter chargers. Anyone see a problem with this circuit?
When an inductive load opens, it usually makes more sense to put the diode across the load (parallel to it, wired "backward") rather than the switch/solenoid. That way, the residual energy in the inductor is absorbed only by the diode, not the battery and everything wired to it.
__________________
diugo is offline   Reply With Quote
Old 22-01-2013, 06:30   #1330
Registered User
 
ebaugh's Avatar

Join Date: Dec 2011
Location: On the boat
Boat: DeFever 44
Posts: 525
These are not for the coils. The intent is to have one path to the battery, but be able to either stop charge or stop discharge individually. That way if a charger hits HVC, the loads remain connected. There would be a slight voltage drop to the loads, but the lights remain on.

I'm not sure how important it is on the LVC side to keep the charger connected. So you could eliminate one of the diode/rectifiers. But it would work both ways if you needed it.
__________________
ebaugh is offline   Reply With Quote
Old 22-01-2013, 07:52   #1331
mrm
Registered User

Join Date: Feb 2011
Location: Poland, EU
Boat: crew on Bavaria 38 Cruiser
Posts: 552
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Quote:
Originally Posted by ebaugh View Post
They would have to be battery isolator sized for the largest of your charge/discharge current expectations.
Technically, no problem, for example:

Vishay VSMD400AW60 | VSMD400AW60

or

Powerex LS410860 | LS410860

Only one of them has to be sized for above max. expected load current. The other has to be rated above max. possible charging current.

Heat will be a consideration. For example, 1.2V drop @ 300A will generate 360W of heat to be dissipated. Probably unrealistic and unnecessary to design for continuous loads of that magnitude though. More likely scenario is a passive radiator and a note to skipper 'use bow thruster sparingly when HVC active'.
__________________
mrm is offline   Reply With Quote
Old 22-01-2013, 08:01   #1332
Registered User
 
diugo's Avatar

Join Date: Dec 2012
Location: Yuma, AZ
Boat: USS Asymptote
Posts: 261
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

I think, in the event of high voltage, it may be more practical to simply send a signal to the charger telling it to stop---avoiding that solenoid and diode altogether.

However, in the event of low voltage, your good idea---the solenoid and antiparallel diode---would disconnect the major loads, but still keep what might be the only charging source connected.
__________________
diugo is offline   Reply With Quote
Old 22-01-2013, 08:17   #1333
Registered User
 
ebaugh's Avatar

Join Date: Dec 2011
Location: On the boat
Boat: DeFever 44
Posts: 525
Quote:
Originally Posted by diugo View Post
I think, in the event of high voltage, it may be more practical to simply send a signal to the charger telling it to stop---avoiding that solenoid and diode altogether.

However, in the event of low voltage, your good idea---the solenoid and antiparallel diode---would disconnect the major loads, but still keep what might be the only charging source connected.
Good luck figuring out which charge source...solar, alternator, AC charger is causing high voltage event...and then finding a marine product with a signal based switch in each category. In normal operation, this event is much more likely than a low voltage event.

In a low voltage event, most likely there are no charging sources present, except perhaps solar or wind.
__________________
ebaugh is offline   Reply With Quote
Old 22-01-2013, 08:26   #1334
Registered User
 
diugo's Avatar

Join Date: Dec 2012
Location: Yuma, AZ
Boat: USS Asymptote
Posts: 261
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Quote:
Originally Posted by ebaugh View Post
Good luck figuring out which charge source...solar, alternator, AC charger is causing high voltage event...and then finding a marine product with a signal based switch in each category.
Nevertheless, it (signaling all charge sources to stop) is the preferred course of action. Otherwise your charge disconnect solenoid suddenly leaves multiple charging sources, all connected to each other, without a battery to take the load.

Quote:
In a low voltage event, most likely there are no charging sources present
Then I am curious as to how you plan to correct the low voltage event without a charging source present?
__________________
diugo is offline   Reply With Quote
Old 22-01-2013, 08:48   #1335
Registered User
 
ebaugh's Avatar

Join Date: Dec 2011
Location: On the boat
Boat: DeFever 44
Posts: 525
Quote:
Originally Posted by diugo View Post

Nevertheless, it (signaling all charge sources to stop) is the preferred course of action. Otherwise your charge disconnect solenoid suddenly leaves multiple charging sources, all connected to each other, without a battery to take the load.

Then I am curious as to how you plan to correct the low voltage event without a charging source present?
Most charging sources are not too concerned about a load, the exception being an alternator. That would need to have the field pass through the aux contacts on a Tyco EV200 or some other mechanism to turn off the alternator.

The low voltage event would have to be cleared manually. I have a bypass switch on my installation that forces the solenoid to close, then charge, then reset the BMS. This bypass is intended only for manual observed use. But if you want it both ways, it just needs 2 diode rectifiers as shown.

Much depends on the battery monitor or BMS used and the specifics of other systems in the boat.
__________________

__________________
ebaugh is offline   Reply With Quote
Reply

Tags
battery, lifepo4, LiFePO4 Batteries, sailing

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
LiFePO4 Batteries - Okay Tear Me Apart ;-) jallum Electrical: Batteries, Generators & Solar 395 03-12-2015 13:19
Voltage drop under load, amps read 99% ?? VVD Electrical: Batteries, Generators & Solar 25 28-06-2011 16:25


Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 15:17.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.