STERLING ULATRA PRO 50 ISSUE

[Cpt Mark]

A few years ago I got rid of my 90's battery charger and went with a Sterling Ultra Pro 50 for a number of reasons but one of them was that it had LiFePo presets and a custom setting for whatever you want. Sounded great.

Reality. The LiFePo presets are not suitable for me. Charging and floating at 14.6. Yes you can charge LiFePO to 14.6 but that is the top end. I want to run my batteries at 14.2 max.

I used the custom setting for 14.2 and the mandatory float at 13.6 (for now). What happened was the 1st time I did this it put out 50 amps, whoo hoo! and then started a 58 minute countdown where the amps dropped every minute. That happened 1 time.

After that, even tho I have cycled on/off it starts out at around 20 amps and immediately counts down to 4-12 amps depending how it's feeling and sometime will display "Ready 0 Volts" and usually but not always on restart will go to "conditioning" on conditioning it does not go above 14.2.

I can turn it off every 20-30 minutes and restart it to put more AH in the battery but this is ridiculous.

I called Sterling and they are all at the boat show. was sent 3 useless videos and given a number to call a guy in the UK which is nice but I have no idea when he goes home or stops answering the phone and since I'm in PST it makes it more challenging.

Does anyone have any experience with this unit that can guide me? I appreciate any help.

Thanks

[lmxr]

When it is not delivering its maximum current of 50A, what is the battery voltage?

[Cpt Mark]

It starts off at 14.1 and is immediately in Conditioning mode which is where it's supposed to be AFTER the bulk charge mode. Within 30 seconds of operation it drops from an initial 20.4A at 14.1 to 10.3A at 14.1.

It will hold here for a while (currently timing it) and then drop to 4A at 13.6V which is the foat voltage I've set. This will happen within an hour or less

[lmxr]

This behavior does not sound abnormal if the battery is close to being fully charged. Does your concern lie in that the bulk phase appears to be skipped, or would you want that the battery charger charges with more current without raising the battery voltage over 14.2 V?

[HeywoodJ]

Originally Posted by lmxr

This behavior does not sound abnormal if the battery is close to being fully charged. Does your concern lie in that the bulk phase appears to be skipped, or would you want that the battery charger charges with more current without raising the battery voltage over 14.2 V?

+1

14.1 is pretty close to 14.2. I'd guess temperature compensation is altering the setpoint just a hair and the charger is seeing the batteries as "full" and switching out of bulk immediately. Sounds pretty normal. The manual is silent on turning off temperature compensation for Li chemistry so maybe a response from Sterling is required.

[Cpt Mark]

It is a new battery I built and installed. Have 2 more to add in process now. Don't want to add them until this one is fully charged so that all are top balanced the same.

On the installed one I discharged it to check it functionality. very happy with the result. The Eve cells are amazing. Since then tho, it has never been recharged to max as the charger seems to not be bulk charging at all. The only way I get anything into it is to turn it off, then back on an repeat the cycle.

[Cpt Mark]

Originally Posted by HeywoodJ

+1

14.1 is pretty close to 14.2. I'd guess temperature compensation is altering the setpoint just a hair and the charger is seeing the batteries as "full" and switching out of bulk immediately. Sounds pretty normal. The manual is silent on turning off temperature compensation for Li chemistry so maybe a response from Sterling is required.

Interesting thought. I don't have a temp probe on the battery from the charger tho. But I think you're right that it thinks it's charged and goes into next phase. I am getting a response from Sterling but it's now their weekend.. sigh

[Dave Lochner]

As others have said, the Sterling/ProMariner batteries initially put out the full current, as the battery reaches a higher state of charge, i.e. closer to fully charged the internal resistance increases which causes the voltage put out by the charger to increase. When it reaches the set point, 14.2 in your case, it switches from a constant current stage (max current with rising voltage) to constant voltage (same voltage decreasing current). The battery's state of charge determines how much current can be accepted at a given voltage. When the current reaches a low point, it will switch in to a float stage at a designated set point. When the battery can no longer accept any current, then the charger shuts down.

[Cpt Mark]

I swapped emails with Sterling in the UK. Based on what they told me it appears my charger is not going to bulk at all or if it is, it's in milliseconds. I've sent them photos and a time log of what happens when I turn the system on. See what they say on Monday. Apparently "conditioning" is the state post bulk and absorption but pre-float. This is where my charger is literally seconds after turning on.

[Boatwright]

I had some questions re alternator modifications to the field connections when installing a Sterling regulator a few years ago. I ended up calling them direct in England after the US distributor was unable to answer them. Mr."Sterling" himself was very helpful.

BTW: This brings up a pet-peeve of mine. The inefficiency of back and forth text messaging when most problems can be solved faster and better by talking.

[svfinlandia]

Originally Posted by Boatwright

BTW: This brings up a pet-peeve of mine. The inefficiency of back and forth text messaging when most problems can be solved faster and better by talking.

+1 Boatwright!

I think they call it a smart phone, not a text phone.
The best communication is person to person. Second is speaking person to person over a telephone or other verbal communications device. It goes downhill from there.

Al, S/V Finlandia

[smac999]

if it's at 14.1v (close enough to the set 14.2) and 10a the battery is full or almost full... the battery is limiting the current not the charger

[Cpt Mark]

Originally Posted by smac999

if it's at 14.1v (close enough to the set 14.2) and 10a the battery is full or almost full... the battery is limiting the current not the charger

The battery is not at 14.1. Initially when 1st turn it on (from power off) the voltage is 14.1 (not the 14.2 it should be) and the amps going in are in the low 20's but after several seconds the voltage goes down and the amps with it. Then it settles on float at 13.6 and 4 amps or it says "ready" zero volts.

The battery is nowhere near full charge. BMS reading 13.5

[lmxr]

Originally Posted by Cpt Mark

The battery is not at 14.1. Initially when 1st turn it on (from power off) the voltage is 14.1 (not the 14.2 it should be) and the amps going in are in the low 20's but after several seconds the voltage goes down and the amps with it. Then it settles on float at 13.6 and 4 amps or it says "ready" zero volts.

The battery is nowhere near full charge. BMS reading 13.5

- So, if I understand correctly, the charger says 14.1 V while at the same time the BMS shows 13.5 V?
- Could you elaborate on how you came to the conclusion that the battery is not fully charged when the BMS reads 13.5 V (I assume this voltage reading is correct)?

[Cpt Mark]

Originally Posted by lmxr

- So, if I understand correctly, the charger says 14.1 V while at the same time the BMS shows 13.5 V?
- Could you elaborate on how you came to the conclusion that the battery is not fully charged when the BMS reads 13.5 V (I assume this voltage reading is correct)?

Unit powered off.
Power on 14.1V amps (starts off 20's and goes down after a few seconds)
within 230 minutes (sometimes faster) it will settle to 13.6 V from the charger and maybe 4 amps. This would be fine if the battery is charged but it is not. Currently battery is at 13.2V.

The issue is it never gets fully charged. In fact, it would appear that if it goes onto bulk charge mode it's in seconds then going into absorbtion briefly the conditioning which is before float.