Cruisers Forum
 


Join CruisersForum Today

Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 09-05-2017, 16:53   #1
Registered User

Join Date: Jul 2013
Boat: Adams 38; sloop
Posts: 72
Can a float current be too high?

Can a float current be too high?

My new Nextstep2 regulator is tripping to float after, say, 1 hour in absorption phase (time set by me). At that point, current is still quite high...over 10A and as much as 18A, under various tests from various discharge states. Float set point is 13.4V.

Can I damage the batteries with this high float current at 13.4V? Battery monitor is then showing positive ah, eg, 10, 15ah etc if engine runs for 15 or 30 mins beyond when it says they are full (at 0 ah). Is this damaging? My old Nextstep1 seemed fine with float current around 2-3 A or less (can't remember clearly; but it died - pot screw stopped responding).

Note: I posted today related issues on this NS2 regulator on a separate thread. This issue on float current was replied to by Main Sail but are there other answers? Thanks.
__________________

jackt is offline   Reply With Quote
Old 09-05-2017, 19:12   #2
Senior Cruiser
 
senormechanico's Avatar

Cruisers Forum Supporter

Join Date: Aug 2003
Boat: Dragonfly 1000 trimaran
Posts: 6,679
Re: Can a float current be too high?

Do you have any loads when this happens ?
How big is your battery bank and what type ?
FLA, AGM, NiCd,, LiFePo4?
Age of batteries and condition of battery terminal cleanliness?
What voltage do you have when alternator says they're full?
Is that voltage measured at battery terminals or at the alternator or somewhere in between. It all matters.
We're here to help.
__________________

senormechanico is offline   Reply With Quote
Old 09-05-2017, 19:20   #3
Registered User

Join Date: Jul 2013
Boat: Adams 38; sloop
Posts: 72
Re: Can a float current be too high?

Quote:
Originally Posted by senormechanico View Post
Do you have any loads when this happens ?
How big is your battery bank and what type ?
FLA, AGM, NiCd,, LiFePo4?
Age of batteries and condition of battery terminal cleanliness?
What voltage do you have when alternator says they're full?
Is that voltage measured at battery terminals or at the alternator or somewhere in between. It all matters.
We're here to help.
Thanks. Please see my other thread where I listed the specs. Voltage is measured at batt by batt monitor. There are some helpful answers from today there also...it might be my batts are just not fully charged before absorption phase terminates at 60 mins and so current is still being accepted...
Thanks.
NextStep2 regulator bulk charge issue
jackt is offline   Reply With Quote
Old 09-05-2017, 20:11   #4
Moderator
 
Adelie's Avatar

Join Date: Feb 2010
Location: La Ciudad de la Misión Didacus de Alcalá en Alta California, Virreinato de Nueva España
Boat: Cal 20
Posts: 8,926
Re: Can a float current be too high?

Yes it can be set too high, yours is not. The battery has not adequately charged if you are still at 10a in float, unless you have a 2000a-hr bank.

Check your battery manual, absorption time should be on the order of 3-4hr.
__________________
Num Me Vexo?
SailboatData
A house is but a boat so poorly built and so firmly run aground no one would think to try and refloat it.
Adelie is offline   Reply With Quote
Old 09-05-2017, 20:33   #5
Registered User

Join Date: Jul 2013
Boat: Adams 38; sloop
Posts: 72
Re: Can a float current be too high?

Quote:
Originally Posted by Adelie View Post
Yes it can be set too high, yours is not. The battery has not adequately charged if you are still at 10a in float, unless you have a 2000a-hr bank.

Check your battery manual, absorption time should be on the order of 3-4hr.
Thanks! Yes, everybody is telling me this and I am finally understanding it. Thank you!

ps. Batt specs below. I posted in my other thread regarding this.
http://usbattery.com/wp-content/uploads/2017/02/usb_2200_data_sheet_2017HR.pdf

http://www.cruisersforum.com/forums/f14/nextstep2-regulator-bulk-charge-issue-179406.html
jackt is offline   Reply With Quote
Old 10-05-2017, 07:51   #6
Registered User

Join Date: Nov 2015
Location: Fl
Boat: Wauquiez Hood 38
Posts: 1,171
Re: Can a float current be too high?

Quote:
Originally Posted by Adelie View Post
Yes it can be set too high, yours is not. The battery has not adequately charged if you are still at 10a in float, unless you have a 2000a-hr bank.

Check your battery manual, absorption time should be on the order of 3-4hr.
Exactly.
__________________
Keth

Boat Vinyl Lettering and Graphics
Bleemus is offline   Reply With Quote
Old 10-05-2017, 08:48   #7
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 26,328
Re: Can a float current be too high?

You don't set current, only voltage.
Bank accepts whatever current it can, no more.
However your earlier comment about not being fully charged is almost certainly what is happening
a64pilot is offline   Reply With Quote
Old 10-05-2017, 09:13   #8
Registered User

Join Date: Aug 2009
Location: Maryland
Boat: Outbound 46
Posts: 248
Re: Can a float current be too high?

We have a large bank, 1000+ amp-hours. If we go down 50%, that's 500 amp-hours. Our shore-power charger can deliver 100 amps, so it is AT LEAST 5 hours to get out of absorption mode. As others have said, if your battery is accepting 10 amps at 14.4 volts, let alone 13.4, it is far from full.
DMCantor is offline   Reply With Quote
Old 10-05-2017, 09:49   #9
Senior Cruiser
 
senormechanico's Avatar

Cruisers Forum Supporter

Join Date: Aug 2003
Boat: Dragonfly 1000 trimaran
Posts: 6,679
Re: Can a float current be too high?

A64's post just above is what I was getting at.
If your boat has other loads at the time, the meter might be reflecting that.
If no other loads and you still have big current on float setting, the cells haven't been fully charged.
__________________
One should try to "Die Young" as old as possible.
senormechanico is offline   Reply With Quote
Old 10-05-2017, 09:57   #10
Are you serious?
 
sailorboy1's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: On the boat somewhere
Boat: Hunter 410
Posts: 15,341
Re: Can a float current be too high?

Quote:
Originally Posted by jackt View Post
Can a float current be too high?

My new Nextstep2 regulator is tripping to float after, say, 1 hour in absorption phase (time set by me). At that point, current is still quite high...over 10A and as much as 18A, under various tests from various discharge states. Float set point is 13.4V.

Can I damage the batteries with this high float current at 13.4V? Battery monitor is then showing positive ah, eg, 10, 15ah etc if engine runs for 15 or 30 mins beyond when it says they are full (at 0 ah). Is this damaging? My old Nextstep1 seemed fine with float current around 2-3 A or less (can't remember clearly; but it died - pot screw stopped responding).

Note: I posted today related issues on this NS2 regulator on a separate thread. This issue on float current was replied to by Main Sail but are there other answers? Thanks.

there's no problem with the amps in float. But your problem is that you aren't staying in absorption long enough.
__________________
jobless, houseless, clueless, living on a boat and cruising around somewhere
sailorboy1 is offline   Reply With Quote
Old 10-05-2017, 12:08   #11
Registered User

Join Date: Jan 2017
Posts: 11,733
Re: Can a float current be too high?

A good charging system, properly configured, won't drop to float voltage level until **after** amps has dropped down to well below .03C, or 3A per 100AH bank size.

Use the configuration options to adjust things until that's what you see while monitoring.

If that is very difficult, consider getting more flexible gear.
john61ct is offline   Reply With Quote
Old 11-05-2017, 15:40   #12
Registered User

Join Date: Jul 2013
Boat: Adams 38; sloop
Posts: 72
Re: Can a float current be too high?

Thanks everyone.

I posted the below Q also over on the other initial thread I have related to this. Clearly, I am not running in abs long enough (1 hr). However, I thought I was running long enough - on my OLD batt bank the bat monitor was saying it was full. See below. Thus, I thought 1 hr would be okay for the new batts too...

Please take a look here too:
NextStep2 regulator bulk charge issue

I also don't understand why on my previous batt bank of 440 Ah, I would recharge each 24hrs from around -50 Ah. Alternator is a Bosch 90 A. This involved say 20 mins of bulk at 60 A to 14.3V and then another 1 hour of absorption at 14.3 V. In that time, my Link10 battery monitor would count back the amp hrs dutifully:
-50...-40...-30...-20...-10...-9...-8...-5...-1...0.
Also, the CURRENT would drop during absorption as expected:
60A...50...40...30...20...10...9...8...7...5...2.
at that point the monitor's algorithm indicated batt was full (algorithm: over 10% total Ah must be drained (>44 Ah) and current must drop to < 2% of declared batt capacity (8.8 A) for 5 mins).
Now it may well be according to your comments I was not running abs for long enough (only 1 hr) and batts were in fact woefully undercharged even though batt monitor said Ah were replaced AND CURRENT WAS < 2%. So were they undercharged or not after 1 hour? Since current acceptance was low - it was < 9 A and went as low as 2 or 3 does it mean they were in fact charged...or instead that the batts were not fully charged and simply could not accept more current because they were damaged? Sulfation? So the amps dropped (due to the regulator algorithm or the batt chemistry??) because they could not be "pumped in"??
jackt is offline   Reply With Quote
Old 11-05-2017, 15:46   #13
Registered User

Join Date: Jul 2013
Boat: Adams 38; sloop
Posts: 72
Re: Can a float current be too high?

Quote:
Originally Posted by sailorboy1 View Post
there's no problem with the amps in float. But your problem is that you aren't staying in absorption long enough.
Thanks. So high amps (20A) at float voltage (13.4V) won't damage anything? It's the high voltage that can damage, right?
jackt is offline   Reply With Quote
Old 11-05-2017, 15:47   #14
Registered User

Join Date: Jul 2013
Boat: Adams 38; sloop
Posts: 72
Re: Can a float current be too high?

Quote:
Originally Posted by a64pilot View Post
You don't set current, only voltage.
Bank accepts whatever current it can, no more.
However your earlier comment about not being fully charged is almost certainly what is happening
Thanks. Please see the Q I just posted which your comment speaks to and perhaps you can expand?
jackt is offline   Reply With Quote
Old 11-05-2017, 15:49   #15
Registered User

Join Date: Jul 2013
Boat: Adams 38; sloop
Posts: 72
Re: Can a float current be too high?

Quote:
Originally Posted by DMCantor View Post
We have a large bank, 1000+ amp-hours. If we go down 50%, that's 500 amp-hours. Our shore-power charger can deliver 100 amps, so it is AT LEAST 5 hours to get out of absorption mode. As others have said, if your battery is accepting 10 amps at 14.4 volts, let alone 13.4, it is far from full.
Yes, at the end of 60 mins abs time, before step to float (13.4V), it was accepting 20A at 14.3V.
__________________

jackt is offline   Reply With Quote
Reply

Tags
current, loa

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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
Has Cruising Become Too Artificial, Too Expensive, Too Regulated ? Piney Our Community 66 26-07-2017 19:01
Float-on, float-off yacht transport video exMaggieDrum Seamanship & Boat Handling 0 09-04-2016 07:46
float switch far away from pump... should I use the neg side for the float switch? felipe Electrical: Batteries, Generators & Solar 13 02-02-2014 13:20
Float voltage too high? stevensuf Electrical: Batteries, Generators & Solar 16 18-06-2012 07:23



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 02:58.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.