Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 23-07-2012, 11:07   #1
Registered User

Join Date: Oct 2011
Location: Wherever the wind takes me
Boat: Bristol 41.1
Posts: 809
Storage batteries and heat

My house bank is located low in the engine compartment of my boat, so it regularly sees high temperatures. Is there a battery type that is less affected by high temperatures, or the corollary, is one type of battery particularly affected by high temperatures?

Is there any analytical data out there, or is it all anecdotal?

TIA
__________________

__________________
redsky49 is offline   Reply With Quote
Old 25-07-2012, 12:46   #2
Registered User

Join Date: Oct 2011
Location: Wherever the wind takes me
Boat: Bristol 41.1
Posts: 809
Re: Storage batteries and heat

Hmm... Lots of views, but no insights.

My suspicion is that during elevated temperatures all batteries suffer degradation regarding life cycles, but also enjoy momentary increases in capacity; and that all battery types act pretty much the same. From what I can discover, that seems to be the consensus.

Doesn't appear to be any actual testing data available on-line to dispute this.
__________________

__________________
redsky49 is offline   Reply With Quote
Old 26-07-2012, 06:40   #3
Registered User

Join Date: Mar 2012
Location: On board in Alanya, Turkey
Boat: Hunter Legend 420 Passage
Posts: 626
Re: Storage batteries and heat

At 25 Deg C batteries gas at 14.4 volts, at 40C they gas at 13.98v - so no sealed batteries should be anywhere near the engine as temperatures of over 40C are soon reached.

Open wet lead acid batteries would be better as they can of course be topped up with water.
__________________
sailinglegend is offline   Reply With Quote
Old 26-07-2012, 08:41   #4
Registered User

Join Date: Dec 2010
Location: W Carib
Boat: Wildcat 35, Hobie 33
Posts: 7,940
Re: Storage batteries and heat

Cooler is better. Not only do they off gas more at higher temps, but batteries can be charged faster at lower temps. Is your charger temperature compensated? If not, you could be cooking your batteries.
__________________
belizesailor is online now   Reply With Quote
Old 26-07-2012, 09:18   #5
Moderator Emeritus
 
GordMay's Avatar

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 31,580
Images: 240
Re: Storage batteries and heat

Batteries intended for high-temperature applications often use a lower initial specific gravity electrolyte (weaker acid) than those intended for use at normal temperatures.

Batteries can be discharged over a large temperature range, but charge temperature should be limited to between 10C and 30C (50F and 86F).

Heat is the worst enemy of most batteries, including lead acid. Adding temperature compensation on a lead acid charger, to adjust for temperature variations, prolongs battery life by up to 15 percent.

The recommended compensation is 3mV per cell, per degree Celsius, applied on a negative coefficient; meaning that the voltage threshold drops as the temperature increases.

Typically recommended Float Voltage thresholds, representing a 30mV correction per cell per 10C (18F):
Normal 25C (77F): 2.30V/cell (13.8V)
Hot 35C (95F): 2.27V/cell (13.62V)
Cool 15C (59F): 2.33V/cell (13.98V)
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 26-07-2012, 09:50   #6
Moderator Emeritus
 
GordMay's Avatar

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 31,580
Images: 240
Re: Storage batteries and heat

Excerpted from ➥ Float Charging - Batterytender.com

... Battery Charger Output Voltage vs. Temperature (Temperature Compensation):
This battery charger characteristic probably has more influence on the battery than line regulation. Even if a battery is kept at its ideal float voltage, and if that ideal voltage is compensated properly for temperature, an increase of only 7 C to10 C can still cut the battery life in half, assuming that the higher temperature remained for the entire observation period.
Short-term fluctuations in temperature have little impact on battery life, unless the temperatures are extreme. In general, cold is good, hot is bad, very cold is better (but too cold can be worse), and very hot is worse.
At the extreme cold end, bad things can happen as well, but those bad things are just dramatic reductions in the battery performance.
At the extreme hot end, while the battery is charging, it can emit dangerous gasses. The ideal temperature compensation range for lead acid batteries is typically in the range of 2.5 to 4.0 millivolts per 2-volt cell, per degree Centigrade. The temperature compensation coefficient is also negative, meaning that the change in charging voltage is in the opposite sense as the change in temperature. If the temperature goes up, the charging voltage comes down and vice-versa ...

Some more light reading about Battery Temperature Compensation

Battery Temperature Compensation

➥ http://www.global-download.schneider-electric.com/852575A6007E5FD3/all/2C44FF0BC409DA0D852576F0006997F0/$File/sp3.1_qa_v3.pdf

http://www.tekrispower.com/pdfs/xant...20Charging.pdf

http://www.boatelectric.com/VictronD...0and%20AGM.pdf
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 26-07-2012, 10:13   #7
Registered User

Join Date: Oct 2011
Location: Wherever the wind takes me
Boat: Bristol 41.1
Posts: 809
Re: Storage batteries and heat

Quote:
Originally Posted by belizesailor View Post
Cooler is better. Not only do they off gas more at higher temps, but batteries can be charged faster at lower temps. Is your charger temperature compensated? If not, you could be cooking your batteries.

Yes, charger utilizes temperature compensation.

"This battery charger characteristic probably has more influence on the battery than line regulation. Even if a battery is kept at its ideal float voltage, and if that ideal voltage is compensated properly for temperature, an increase of only 7 C to10 C can still cut the battery life in half, assuming that the higher temperature remained for the entire observation period."

The key here is that the elevated temperatures are only for the period when the engine is operating. In my case, my diesel auxiliary sailboat only sees engine operation, on average, less than 2% (probably far less) of the time on an annual basis. Additionally, my batteries are lower than the engine and extend away from the engine in an end-to-end arrangement so heat soak is less of an issue than it might be.

This year I am going to monitor the actual engine room temps at both high and low heights and see what actually is occurring. I am in the process of changing over from gel cells to wet, and will try to record my experience for anyone who might be in the same boat

My sense is that there is an overwhelming amount of anecdotal information, second hand opinion, and outright misinformation circulating out there regarding batteries. If you exercise some common sense, any battery will work remarkably. Case in point, my current Prevailer gel cell 4Ds range in age from six to eleven years. The oldest batteries have diminished in capacity and are now starting to bulge/leak. I have certainly gotten my money's worth!
__________________
redsky49 is offline   Reply With Quote
Old 26-07-2012, 10:32   #8
Commercial Member
 
CharlieJ's Avatar

Cruisers Forum Supporter

Join Date: Dec 2008
Location: St. Petersburg, FL
Boat: Gulfstar Long Range Trawler; 53'; BearBoat
Posts: 835
Re: Storage batteries and heat

Quote:
My sense is that there is an overwhelming amount of anecdotal information, second hand opinion, and outright misinformation circulating out there regarding batteries.
True enough. However; the battery manufacturers' websites generally have detailed information and will often provide graphs showing loss of cycle life as a function of environmental temperature.

Charlie
__________________
Charlie Johnson
JTB Marine Corporation
"The Devil is in the details and so is salvation."
CharlieJ is offline   Reply With Quote
Old 26-07-2012, 11:18   #9
Registered User

Join Date: May 2011
Posts: 132
Re: Storage batteries and heat

Why not just add power ventilation to the battery box? It seems that with so not only the heat problem but would also get rid of explosive gases. Just my two cents, Mike.
__________________
Florida Mike is offline   Reply With Quote
Old 26-07-2012, 12:06   #10
Senior Cruiser

Cruisers Forum Supporter

Join Date: Jul 2006
Location: Chesapeake Region and Maine
Boat: 42' Bob Perry sloop
Posts: 4,038
Images: 4
Re: Storage batteries and heat

Mike beat me to it: definitely think about engine room ventilation; even a 3-4" muffin fan (like on a computer) blowing across the batteries would help.

Also, borrow or buy a laser temperature meter (they're cheap these days). Measure the temp of the batteries at various points, including: engine off, engine running for 15 minutes, engine running for several hours. Record also the ambient temperature.

That will give you a pretty good idea of what's going on.

And....if your gels lasted as long as they have, I'd say you really don't have a problem to worry about the way you use your boat.

Just be careful to watch the electrolyte levels on the new flooded batteries. I use WaterMiser caps to reduce water loss; well worth the investment and they don't have to be removed when equalizing batteries as do the HydroCaps.

Bill
__________________
btrayfors is offline   Reply With Quote
Old 26-07-2012, 14:35   #11
Registered User

Join Date: Oct 2011
Location: Wherever the wind takes me
Boat: Bristol 41.1
Posts: 809
Re: Storage batteries and heat

One of the nice things about an older center cockpit boat is the possibility to have a real engine room, small certainly, but adequate. It also allows, in my case, for no less than five access doors to the engine, one of which is usually open when motoring for extended periods.

Despite that, a small supply air fan, wired in to the engine start wiring makes sense. I will just have to think through the location so as not to introduce a path for noise into the boat, or to create any incidental problems.

I do have an IR thermometer. It just needs to move from work place to play space. It will be interesting to see the results.

Do watermiser caps raise the height of the batteries substantially? How much do they reduce the need to water the batts?

My past experience with paralleled Trojan SC225 flooded batteries was that water needed to be added every couple months. Not a terrible burden, but my current battery installation is more difficult to access, and if I could lengthen the service periods, that would be good. I also am going to try to raise (very slightly) the charging voltages, so I may use more water than planned.

Appreciate all the input!!!
__________________
redsky49 is offline   Reply With Quote
Old 26-07-2012, 21:36   #12
Marine Service Provider

Join Date: Oct 2011
Posts: 1,205
Re: Storage batteries and heat

I have my batteries connected to a voltage switch, as soon as the voltage reaches 14.4 volts an outside fan comes on and stays on until the battery voltage drops to 13.2.

I also have a temp switch that comes on and ducts a seperate outside air fan to my alternators, as soon as the temp rises abvoe 120 F , and off at 100F.

In this day and age it is very simple to extend the life of most heat sensitive devices.

Lloyd
__________________
FlyingCloud1937 is offline   Reply With Quote
Old 26-07-2012, 21:46   #13
Registered User

Join Date: Jan 2012
Location: CHARLESTON, SC
Boat: IRWIN 10/4
Posts: 58
Re: Storage batteries and heat

If you like following engine room temperatures for a long period, or short period, one thing I use is a LASCAR EL-USB data logger, temperature monitor. It's a USB probe, very small that you set up on a computer, it has a small battery, and it will take thousands of samples. Every second, 5 seconds, minutes, hours, days, etc. They also have current and voltage monitors. Just another toy, but it gives you an idea what's happening if you are trying to fine tune a battery system at the engineering level.
__________________
RUSTYNAIL is offline   Reply With Quote
Old 27-07-2012, 09:52   #14
Registered User

Join Date: Oct 2011
Location: Wherever the wind takes me
Boat: Bristol 41.1
Posts: 809
Re: Storage batteries and heat

Two great suggestions from Flyingcloud and Rusty.

As a retired engineer, never pass up on a chance to make things overly complicated, or add a new gadget

I am looking forward to seeing what the actual temperatures - both engine space and batteries - are during extended motoring. For some inexplicable reason, I have not checked this before. Logging the temps should be interesting, and hopefully, informative.

Having had some exposure in the past to industrial ventilation (though on a much bigger scale) this will be a nice project.

Thanks!!
__________________

__________________
redsky49 is offline   Reply With Quote
Reply

Tags
storage

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




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 10:51.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.