I just got this charger. When connected to a mostly charged battery (12.4 volts) I've notices that it seems to charge at 15.9 volts - low current 3 amps or less. This seems too high. It's running outside, 17 degrees temp. This is the voltage as reported by the charger, so it knows it's hitting that level.I wonder if I should ever see such a high voltage in a regular charge cycle? Also, it seems like this charger may not be safe to use on a battery that is hooked up to a trailer or car?

The 1093DBD is temperature compensated on nominal 14.8v at 77F. My chart only goes down to 32F, but that would be 15.3v equivalent, so 17F would be higher than that. So your 15.9 seems reasonable.However, the RV fridge control high limit is 15.4v and that is not temp comp, so you raise a good point to not use the charger when it is below freezing unless you disconnect the batteries from the Rv first, just as you would if equalizing in mild temperatures.

I also found this thread: Crown Battery raises recommended absorption VoltageBFL13 wrote:Not so fast! They still want (in the charging guideline) the "finish stage" (which follows the shortened-in--to about 92% SOC-- "absorption stage") to be constant 3-4 amps per 100ah and to go to 2.65v per cell, which is 15.9v.That "finish stage" was fitted in where the last part the longer full "absorption stage" was with the two stage profile that went to 97% .That is not weekly equalization either, that is the everytime recharge. When you equalize, you run the finish stage an extra three hours.Which is all very like Interstate saying to do an equalize every time after the end of the absorption stage in the two stage profile on their 6s. It is possible that these chargers are now doing this higher voltage all the time, or is it more likely that the temp compensation curve just doesn't have a hard cutoff for high voltage?

mrekim wrote:It is possible that these chargers are now doing this higher voltage all the time, or is it more likely that the temp compensation curve just doesn't have a hard cutoff for high voltage?There aren't any chargers that perform the function that BFL mentioned (finish charging). I don't remember where the VEC's cut off is. It might be 16V.

I NEVER bank on what a single meter tells me. I need a 2nd opinion :)

Smart Charger Voltage 15.9 volts ? (VEC1093DBD)

20 Replies

BFL13
Explorer II
Jan 24, 2014
mrekim wrote:
BFL13 wrote:
It should be around 14.8 at 68F.

If you have somehow hit Equalize (green light flashing) by poking a pin in the hole for that, then it would go into the 15s (15.7v nominal for Equalize.)

Nope, it's not in equalize.

I went and got an IR temp meter. I was off the temp in the basement. I shot the battery and the charger and got 55-56 degrees. Doe that seem more reasonable for a regular cycle?

The table I have for equivalents to 14.7v at 77F is that at 55F it would be 14.99v. So it may not be that far out of whack, but at the high end of whatever its +/- margin of error is?

I have not done a calibration check on mine but it certainly does the temp comp. It will go over 16v in Equalize in cold temps.
mrekim
Explorer
Jan 24, 2014
I found a table:

Temp Voltage
80 14.2
70 14.4
60 14.5
50 14.8
40 15.0
30 15.2

Is this right? If it is this charger may be screwed up :(
mrekim
Explorer
Jan 24, 2014
BFL13 wrote:
It should be around 14.8 at 68F.

If you have somehow hit Equalize (green light flashing) by poking a pin in the hole for that, then it would go into the 15s (15.7v nominal for Equalize.)

Nope, it's not in equalize.

I went and got an IR temp meter. I was off the temp in the basement. I shot the battery and the charger and got 55-56 degrees. Doe that seem more reasonable for a regular cycle?
BFL13
Explorer II
Jan 24, 2014
It should be around 14.8 at 68F.

If you have somehow hit Equalize (green light flashing) by poking a pin in the hole for that, then it would go into the 15s (15.7v nominal for Equalize.)
mrekim
Explorer
Jan 24, 2014
MEXICOWANDERER wrote:
I NEVER bank on what a single meter tells me. I need a 2nd opinion :)

I didn't double check the 15.9 but I have it in the basement now on different batteries and the VEC is reporting 15.3 and my meter (Fluke77) is reporting 15.14. It was charging between 3 and 4 amps. Temp is probably between 63 and 68 degrees.
tvman44
Explorer
Jan 24, 2014
Seems too high to me. :E
MEXICOWANDERER
Explorer
Jan 24, 2014
I NEVER bank on what a single meter tells me. I need a 2nd opinion :)
mena661
Explorer
Jan 24, 2014
mrekim wrote:

It is possible that these chargers are now doing this higher voltage all the time, or is it more likely that the temp compensation curve just doesn't have a hard cutoff for high voltage?
There aren't any chargers that perform the function that BFL mentioned (finish charging). I don't remember where the VEC's cut off is. It might be 16V.
mrekim
Explorer
Jan 24, 2014
I also found this thread:

Crown Battery raises recommended absorption Voltage

BFL13 wrote:
Not so fast! They still want (in the charging guideline) the "finish stage" (which follows the shortened-in--to about 92% SOC-- "absorption stage") to be constant 3-4 amps per 100ah and to go to 2.65v per cell, which is 15.9v.

That "finish stage" was fitted in where the last part the longer full "absorption stage" was with the two stage profile that went to 97% .

That is not weekly equalization either, that is the everytime recharge. When you equalize, you run the finish stage an extra three hours.

Which is all very like Interstate saying to do an equalize every time after the end of the absorption stage in the two stage profile on their 6s.

It is possible that these chargers are now doing this higher voltage all the time, or is it more likely that the temp compensation curve just doesn't have a hard cutoff for high voltage?
BFL13
Explorer II
Jan 24, 2014
The 1093DBD is temperature compensated on nominal 14.8v at 77F. My chart only goes down to 32F, but that would be 15.3v equivalent, so 17F would be higher than that. So your 15.9 seems reasonable.

However, the RV fridge control high limit is 15.4v and that is not temp comp, so you raise a good point to not use the charger when it is below freezing unless you disconnect the batteries from the Rv first, just as you would if equalizing in mild temperatures.

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Smart Charger Voltage 15.9 volts ? (VEC1093DBD)

20 Replies

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