How to set Battery Charge Rate on Trace DR 2412

bgmills

I have an RV outfitted with a Trace DR 2412 Inverter/Charger. I have changed the battery configuration. I am trying to interpret the manual in order to adjust settings for the new config. The documentation is vague and provides little useful information regarding the device settings particularly in regard to the Battery Charge Rate. The pot on the unit is supposed to be set in Amps but provides no incrementation or numbering on the dial. I can't tell if this is to be set by percent or a scalar value in amps. The instructions say to calculate the value in amps but there is no meaningful way to implement given the design of the panel on this unit.

Anyone have any experience with setting up one of these?

RCinFLA

Re: How to set Battery Charge Rate on Trace DR 2412

Charge rate adjustment pot is roughly linear.

For DR2412 100%, fully clockwise is about 120 amps. 50% is roughly 60 amps.

Start by turning the pot fully counterclockwise to see where the screwdriver blade points with respect to min setting printed on front panel.

There is a lot of variation particularly with AC line voltage since the charger is basically the transformer in reverse with rectifying diodes. This is especially so when using a generator as charging source. Charging load on AC source has a poor Power Factor (PF) so you can easily load down the peak voltage on a generator without any noticable straining of the generator's engine.

I strongly advise you to invest in a low cost clip on DC capable ampmeter like the one here. Or you can get a battery monitor like Trimetric unit with 500 amp current shunt to display battery current.

http://www.sears.com/shc/s/p_10153_12605_03482369000P?prdNo=2&blockNo=2&blockType=G2

http://www.solar-electric.com/trtmbamosy.html

bgmills

Re: How to set Battery Charge Rate on Trace DR 2412

Thanks RC. Useful information. I am charging from AC. I have an ammeter on the internal DC circuit but not on the charging circuit. I am using a Greenlee induction meter to measure the charge current.

With the pot at max, in bulk mode my meter peaked at around 22 amps but settled around 14, in absorption phase it was running around 8-10. The main problem I am having right now is that the Trace seems to go quickly through the bulk and absorption phases even after I have put heavy loads on the battery.

My ammeter shows that it is charging but only for a brief period before it goes to float and the battery voltage never goes back to full charge (12.4 instead of 12.8 vdc). Even though it goes to float, it doesn't seem to actually be fully charging the batteries. I have had to fully recharge with an offline deep cycle charger.

I see the 0-120 in the spec sheet although that doesn't correlate with my measurement. With two 92 amp/hr batteries using the recommended calculation, 184/5=36.8. So if set by percent the pot should be set at 31%. I will try that. Anything else that could be causing it to truncate the charge cycle? The manual seems to suggest reducing the battery size setting. I have it at 170 now.

bgmills

Re: How to set Battery Charge Rate on Trace DR 2412

By the way. These batteries are AGM. There is no setting in the manual for this. I have it on type 5. Maybe it should be on 7.

RCinFLA

Re: How to set Battery Charge Rate on Trace DR 2412

bgmills wrote: »

By the way. These batteries are AGM. There is no setting in the manual for this. I have it on type 5. Maybe it should be on 7.

Look at table 3.1 in owner's manual and select the setting that best matches your battery manufacturer's float and absorb voltage. Absorb voltage is called 'Bulk' in their manual table. (I consider the name 'bulk' to be the first stage constant current phase, which is your pot setting)

For AGM, it is usually Lead-Calcium sealed setting, which is switch position 6. Position 5 is another possiblity for slightly higher float voltage. Setting 7 may give you a too high float and absorb voltage, but again, refer to your battery recommendation.

The table heading of 'Bulk/Equalize' means for an normal bulk or equalize switch setting. Setting 0 and 1 are for Equalizing which you should be careful using on AGM sealed batteries.

Some AGM manufacturers do specify using a short equalize cycle but usually only if you are having problems with the battery. AGM use oxygen recombination which recycles hydrogen/oxygen back to water in a sealed case environment. An equalize high voltage overcharge may create so much gas the recombining process on an AGM can not keep up, so internal pressures within case rise and the safety value vents (typically an audible high pitched squealing sound) to relieve pressure within the case. This is a safety valve to avoid case splitting, or exploding. The result of venting AGM (or any sealed lead acid battery) is loss of water that cannot be replaced.


The DR2412 should push out 120 amps max charging current, if the battery is discharged enough, and the AC input is 120 vac. You may be getting the lower current readings because the battery is already charged and it is going into absorb (constant voltage phase). Check it when your batteries are discharged 20% to 40% (60% to 80% SOC).

bgmills

Re: How to set Battery Charge Rate on Trace DR 2412

OK. Excellent feedback. I have adjusted the Max Charge Rate per your suggestion to my best guess as to what 31% might be on the dial. It helped a little but it's still going to float far too soon.

I will check the battery specs and try 6 and maybe 7 (watching the battery temp) just to see if it has any impact on the charging cycle. I have put a battery temp sensor on the Trace with the expectation that it will limit overcharging, although there isn't much documentation on that either.

I am just concerned that the Trace seems unable to reach full charge on these batteries. When I put my BatteryMinder on them off line, it charges for a couple of hours at 8 amps to get to float (after being discharged to around 12.1) but then registers a full charge with standing voltage at over 12.8. The Trace goes to float in a less that 5 minutes and never seems to fully charge the batteries (how could it unless the charge current was exceptionally high?). Usually reads around 12.4 after it goes to float. That is considerably less capacity.

Thanks again for you help!

bgmills

Re: How to set Battery Charge Rate on Trace DR 2412

Having followed RC's advice and doing some extensive testing I have come up with correct settings for this unit and battery combination. I now have a pretty good understanding of how to configure it in case anyone else is interested. What I discovered, however, is that the problem I was experiencing with the unit truncating the charge cycle was directly correlated to the addition of a battery temperature sensor. There is no documentation in the manual about the function of the temp sensor other than saying that it protects the batteries from over charging. Sounds like a good idea. That may well be true because it seems to immediately interrupt the charging cycle.

As part of my testing, once I got the settings right, I ran the charging cycle with and without the temp sensor. Without the temp sensor, the unit charges to spec. With it connected, the charging cycle is truncated, voltage drops from 13.6 to 12.5 in float and current drops from 9+ to about .5 amps within 1 minute. The charging cycle never completes, so I have disconnected it. Anyone have any idea what is going on with this? Did it ever work? What is it doing or not doing?

BB.

Re: How to set Battery Charge Rate on Trace DR 2412

What was the actual temperature of the battery sensor (or the point on the battery to which it was attached)?

If the sensor was on a battery post--and there was poor electrical connection--it could heat the post up and cause the Charger to drop the charging voltage/set points down.

-Bill

RCinFLA

Re: How to set Battery Charge Rate on Trace DR 2412

Temperature compensation just changes the absorb and float voltage settings versus temp. Basically the hotter the battery is the lower the set voltages.

http://www.powerstream.com/SLA.htm

The DR series charging regulation for current is not very accurate or stable as it will become a function of AC input voltage to the unit. Voltage regulation at the absorb and float levels are okay.

Your battery should not be getting warm during normal charging unless you are pumping too much current into it during the bulk first stage of charging for the AH size of the battery.

Don't go over 12% to 15% of AH rating for the constant current bulk phase.

Blackcherry04

Re: How to set Battery Charge Rate on Trace DR 2412

When Xantrex replaced the DR series with the TR series they made the charging algorithm even crazier. As your battery's age or if you have any drain on them, it will drive you crazy with it's charge cycles. I keep mine faked out with a trickle charger, otherwise it will keep on initializing a new full charge cycle.

Float Charge
Float charge, the final stage of battery charging, maintains a charge to the
batteries for 1 hour as long as AC is present on the inverter’s input. Float
charging reduces battery gassing, minimizes watering requirements (for flooded
batteries) and ensures the batteries are in a constant state of readiness. The
Charge Mode indicator light is illuminated green.
After 1 hour at float charge, the Xantrex TR Series will transition to Standby Mode.

Standby Mode
The Xantrex TR Series will transition to the Standby (charger OFF) Mode after 1
hour in the float stage. In standby, the Charge Mode indicator light is solid green
and the display screen shows "---".
A new charge cycle will be initiated if the battery voltage drops below 12.5 Vdc
(for 12 V models) or 25 Vdc (for 24 V models) while in Standby Mode. You can
manually initiate a new charge cycle while in Standby Mode by pressing the
ON/STANDBY switch once, to transition the Xantrex TR Series to OFF, then pressing
the ON/STANDBY switch again.
If qualified AC power becomes not available while the Xantrex TR Series is in
Standby Mode, it will automatically transition to Invert Mode and begin taking
power from the batteries.

bgmills

Re: How to set Battery Charge Rate on Trace DR 2412

OK. Sounds like the Charge Rate should really be about half of what the manual recommends (31% in this case). As currently configured (w/o temp sensor), when the battery is at 80-90% capacity, the bulk charge phase (orange light) is relatively short, perhaps 5-10 minutes, then it goes to absorption phase (flashing orange) for about 10 minutes then settles to float (green). There does not seem to be any standby mode. It will just stay in float and hover near 100% depending on the load. You can hear a soft rising and falling hum but it never stops entirely. There is nothing in the manual about standby.

I don't know the actual temp at the terminal but I do not detect any noticeable heat from touch after charging. I had the temp sensor connected to a screw post (negative) directly on top of the battery cables. With the temp sensor connected, no mater what my settings on the charger, it always truncated the charge cycle after a couple of minutes--going to float and leaving the batteries in a less than fully charged state. So, I have disconnected it.

After a four day trip this past week, everything seemed to work without a hitch. With fully charged batteries and a little sun, my solar charger (Solar Boost 2000E) now goes to standby indicating that the batteries are at full charge after a charge cycle. Unless my batteries conk out unexpectedly for some reason, I think things are working great!

Thanks for all the great feedback.