View Full Version : Batteries Not using any water
March 17th, 2008, 10:46 PDT
bluesky 2512i with IPN pro remote
3 everstart deep cycles.
Almost every day for the last 5 months my monitor has indicated a 100 % state of charge by sundown. Every time I've checked the h20 level in my 7 month old batteries I have not had to add any water.
For a while it was not going into acceptance mode. A lower float current remedied that.
I have noticed that several different digital multimeters have read between .1 and .2 volts lower than the battery monitor.
When in acceptance mode the meter reads 14.4 volts and the DMM reads 14.25.
When in float mode the meter reads 13.2 volts and the DMM reads ~ 13.08.
Should I set the acceptance and float voltages higher?
How long should I set the acceptance time?
March 17th, 2008, 11:00 PDT
that would depend on what you trust moreso. if it were me i'd trust that several of the more accurate dmms have consistantly shown a differing voltage. look at the specs for accuracy on each meter too and i'll bet the farm that the dmms with be far more accurate than a battery monitor. now which dmm to go with is the big question. some makes are known to be very accurate too so maybe you might say which dmms were used and measured what specific voltage.
edit to add:
i set my parameters by a dmm though my controller's meter seems to be accurate enough for me to set things by.
March 17th, 2008, 11:26 PDT
Though my DMM is a Cen-tech harbor freight special it has always read within .05 volts of every other (4)DMM's I've borrowed Which is always at least .1 volts lower than than the monitor.
I'm bumping up both .1 volts right now. How much time should I allow for acceptance with my setup?
March 17th, 2008, 12:05 PDT
Sounds like you don't have a BTS for your unit ( battery temp sensor )
If this is the case, and your battery's are colder than 25C you will need to boost the voltage according the the manufactures recommendations
March 17th, 2008, 12:18 PDT
see page 5 on acceptance charge.
you do not have to change the voltage setpoint for acceptance as that you can leave at the 14.4v i believe you have it set at. in having 3 batteries at about 100ah each this means about 4.5amps for the float switchover point.
edit to add:
on second thought add .1v to it as you're not seeing the voltage properly on your monitor. 14.4v is good with an accurate meter.
March 17th, 2008, 18:21 PDT
Another concern is have you ever had an equalize cycle run ? That will bubble off some water, and top the charge off too.
I don't know if it's kosher to force an EQ during Bulk, and let the EQ top off the cells, or is Acceptance part of a needed pre-cycle ?
March 18th, 2008, 10:08 PDT
The 2512i does not have the option for the temp sensor, nor the equalize function, so I have never equalized the batteries. However this system is installed in a daily driven Van so stratification is less of a problem. My alternator will bring the voltage up to 15 for short periods, but little is asked of it now and the output falls to the 2 to 5 amp level within 5 minutes of driving.
I do have a wall charger which does not claim to have an equalize function but never the less will bring the batteries upto over 15 volts, but have had no need to use it in since I hooked up the panel, as I seem to have a electrical surplus on any day with just a few hours of sun.
My monitor displays my battery min and maximum voltage. Before the acceptance stage started working properly this number would be around 11.7 as the starter turned the engine turned over. After the acceptance stage started working this number rose to 12.2 volts. This morning ,after raising the acceptance and float voltages by .1 volts yesterday, the minimum battery voltage read 12.3 volts. This was despite using slightly more amps last night, and starting the van a little earlier, on a cooler than average morning.
Thanks for the info!
March 18th, 2008, 13:31 PDT
1) van alternator will only output about 13.8V . Deep Cycle needs almost 15V
2) Equalize is also needed to balance the cell voltages, and should be done monthly to keep the battery healthy.
3) are you using a Starter Battery or a Deep Cycle battery, they differ about a volt in fully charged conditions, and paralleling a deep cycle with a starter battery, will, in several months, destroy the weaker battery.
March 19th, 2008, 10:00 PDT
Fwiw, I regularly see 14.8 volts at the batteries from my alternator, and I'm using 3 duplicate deep cycles in parallel with the option of isolating the engine compartment battery. One deep cycle battery has enough CCA to start my van easily in my climate.
Since my batteries rarely drop below the 90% level the alternator doesn't have to work very hard, and the meter drops down to 13.4 volts and 4 to 6 amps pretty quickly. The one time I disconnected the panel till I reached the 50% level, the meter, after starting the van, held at 14.8 volts and well over 50 amps for the 90 minute drive.
Somewhat surprisingly, setting the max battery volts on the monitor limits the alternator voltage as well, unless the meter is lying.
I wonder if I could simulate a equalize charge by temporarily setting my acceptance voltage to 15.2, and making sure none of my 12 volt electronics are turned on.
March 19th, 2008, 12:10 PDT
I regularly see 14.8 volts at the batteries from my alternatorThat used to be rather unusual. For example, the most I've ever seen at the battery terminals in the engine bay of my 10-year old Ford F-250 Super Duty is 14.2 V, IIRC. It does seem like alternator regulator voltage in newer vehicles is creeping up, though... What brand and year is your RV's chassis? Is it possible you have a special "RV" regulator? Have you had any problems with the starter battery (i.e., short life)?
I wonder if I could simulate a equalize charge by temporarily setting my acceptance voltage to 15.2, and making sure none of my 12 volt electronics are turned on. This should work. Just do it after the controller has completed its "regular" absorption charge.
Jim / crewzer
March 21st, 2008, 9:55 PDT
My DIY dodge camper van is old enough to vote, and the regulator is within the rebuilt engine computer. I don't know if A1 Cardone increased the regulator's output.
I have put on a 130 amp alternator, but cannot explain the regular 14.7/8 readings I get. I did replace the stock gauge atl. cables with 2awg. The readings were taken from the house battery bank, the monitor displays .1 volt higher. The engine compartment battery equals the house bank.
I honestly don't know how my alternator kept up before I got the solar setup. In fact it didn't and I wound up plugging a charger in every few days.
My previous battery problems were all caused by three different make and ages of batteries. They still lasted a minimum of 3 years.
Thanks for the input.
Wayne from NS Cana
March 22nd, 2008, 5:06 PDT
Just a note on automotive battery voltage here in my part of Canada. Perhaps the regulators destined for our somewhat colder climate are set for a higher voltage than warmer parts of the world. I can't remember any of the many vehicles I've checked here as far back as the 70's having significantly less than 14.5 at the terminals of a charged battery with a properly operating alternator. But likewise, I've noticed an upward creep in voltage over the years and put it down (as a guess at the time) to new battery technology requiring it. I was also told in the 1980's by some supposedly top automotive people that starting in the 80's, automotive alternators had built in temp compensation to boost battery voltage in cold weather. Strange how I wondered even back then how that would work - - the alternators we were talking about had the regulator built into the alternator which under heavy load would run too hot to touch. Hummmmm, perhaps they used an early version of bluetooth to a sensor embedded in the battery. :p:p
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