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sieade245 avatar image

Phoenix Battery Charger Bulk Protection

Hi everyone. I've got a snag on one of our installations. There are 3 24V battery banks A200 of 12x2V cells 225Ah total capacity each bank. Each is charged using Phoenix 24/16 charger using default factory settings.

During a recent inspection, we depleted each bank to around 23.5V and then charged them back up again. Each Phoenix charger failed after between 6-7 hours. There is a solid red fail LED illuminated but nothing else.

For the main bank, we swapped in another phoenix and exactly the same problem after 6-7 hours. A skylla-TG 24/50 was then installed instead and set to 16A charge current. This failed after 10 hours with a flashing bulk, steady fail LEDs. This indicates bulk protection mode has kicked in (there is conflicting info in the manuals, one of them says it will swap straight to float, but another manual says it will fail with LED code as above).

So I'm thinking we need to increase the charging current to at least 25A for a c/10 rate. I manually set it to 40A just to get the batteries recharged and this worked fine.

My question is. Is this what is causing the Phoenix 16A chargers to fail also? I looked at the manual and also in google. There is no mention of this series having bulk protection mode. Also, if there is bulk protection mode does it default to 6-7 hours? We had exactly the same issue last year on another site, with both phoenix chargers failing after 6-7 hours but just gave up and swapped them for skyllas which have been fine. I can't believe that all our phoenix chargers are faulty though. This does not happen in float mode with already charged batteries, only after bulk mode has been on for 6-7 hours (best I can do from telemetry indications). The ambient temperature is around 10-15 degrees C and there is around 2 feet spacing around each charger. They do not get hot and the fans are working. The batteries are 2 years old. On the other site, they were 3 years old. Fitting a skylla removes the issue (at both sites).

Just to be clear. These are the Phoenix chargers, not the inverter/ multiplus units.

MPPT - Solar Charge ControllerPhoenix Invertercharger
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2 Answers
sieade245 avatar image
sieade245 answered ·

Hi Daniel. Yes they all will restart correctly after a power cycle. The problem is we have to physically go to the station to do this. I've done some more work on this fault since I posted the question. Each battery bank is 225Ah we have 5 banks across two sites. The station load was around 10A and they are the 16A versions of the charger resulting in a charge current of only 6A. Each charger will fail a few hours after switch on. I brought one back to the workshop and put it on the bench, connecting it to a load bank drawing 10A and a completely different battery bank in parallel which was around 50% SOC. The charger failed in the middle of the night. I'm going to connect it up to a scopemeter and log how long it is before they fail.

As the new phoenix charger-I has bulk protection which is user configurable via Bluetooth, and its clearly documented in the manual, I was guessing that the old version also has some kind of bulk protection feature but just need confirmation. We've replaced the two main chargers with Skyllas 30A which should get the bank charged back up before bulk protection kicks in.

We've reached out to our distributor but they don't know the answer, they were going to refer us to Victron support but that was 2 weeks ago now not heard anything back is there anyone I could contact at Victron directly who would know the answer to this?

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Hi @sieade245

Can you connect the Phoenix with MK3 - usb cable to computer to check the settings?

sieade245 avatar image sieade245 Daniël Boekel (Victron Energy Staff) ♦♦ ·

Hi Daniel. I have all the programming kit sure....but I've never used this on a Phoenix before. Multiplus/ Quattros yes. There is a port on the Phoenix but the manual only mentions using it for the external remote panel. Are you saying I can connect to it with VEconfigure? Or a different program. This is news to me, I would have tried this earlier. I'm off work for Christmas but I can try plugging a MK3 in when I get back

Matthias Lange - DE avatar image Matthias Lange - DE ♦ Daniël Boekel (Victron Energy Staff) ♦♦ ·

Will the MK3 work with an "old" Phoenix?
I thought you will need a MK2 for that.

I'm not sure, what is the model and firmware number of the device?

sieade245 avatar image sieade245 Daniël Boekel (Victron Energy Staff) ♦♦ ·

I have both MK2 and mk3 programmers available. I can try both not sure on firmware details until I get back to work

sieade245 avatar image sieade245 Daniël Boekel (Victron Energy Staff) ♦♦ ·

Hi. I tried both the MK2 and MK3 USB programmers. The MK2 worked fine with VE configure and the charger connected immediately. The MK3 would not detect the charger. Tried a couple of ethernet leads just to rule out but just doesn't see it. Not an issue for us as we have both versions...although I was going to replace all the MK2s with MK3 obviously this would not be a good idea! Are there any other devices that will only work with a MK2 and not MK3?

When connected, I was able to use VE Configure to disable bulk protection and also storage mode which we don't want. I'm still surprised that none of this is in the charger manual though. This affects every site we've got this chargers installed at as we simply weren't aware that bulk protection is built in.


Firmware is 1411120

Model Phoenix Charger 24/16 HQ1523QIQKY (from main board)


I've got them on a long term bulk test now on the bench with a load bank I'll update if the charger doesn't fail. Before the programming, they would fail every night.



Hi @sieade245

Thanks for the update, MK2 is for old products without ve.bus connection.

I agree that documentation is not complete on this!

You should keep the MK2 as long as it's working.
I also have one in my laptop bag because of that and the MK2 also working with new devices.

Just to follow up on this. Our phoenix charger on the test bench worked in Bulk mode for over 24 hours after applying this fix. Many thanks to everyone who helped. Going to apply this to all of our chargers in the field ASAP.

Daniël Boekel (Victron Energy Staff) avatar image
Daniël Boekel (Victron Energy Staff) answered ·

Hi @sieade245

Does the Phoenix charger start again after a power cycle?

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