Fogstar Drift Problems. (1 Viewer)

[RogerIvy]

BMS reporting 100% battery still charging at 5 amps for about 15/20 min then dropping to 0.

[/QUOTE]
What are your OVP and Cell Full voltages.

 

[Lenny HB]

What are your OVP and Cell Full voltages.

Overall voltage on both batteries was 14.2v I can't rem er what the cell voltages were.

 

[ChrisL]

Difference appears to come about while charging from the B2B on the way home

RogerIvy I notice that my Victron B2B does not have a charged voltage and tail current setting like the solar controller does, so do you know how it decides when to go to absorption and float?

 

[paddymcc]

Join the club Lenny HB. After my episode of “imbalance” and all the contributions on here I realised that for twelve years I have had no idea whether my two or for the last eight years three LA batteries were balanced or not and I never gave it a thought. But now I can see everything that is going on so I can worry about it. But as has been said above the Lithium batteries are bound to have different internal resistances so will obviously discharge at different rates in the same way LA’s would. It is the amount that was the most startling. I have now come to the view that the BMS’s should be looked at like a fuse. Don’t even think about it, It is there to protect the battery from over charging, over current, low temperature and low soc. Hopefully it will do that with better reliability than the figures it sends us via Bluetooth to the app. Only time and usage will tell. I now only look at the Shunt output because that appears to be far more accurate. Unfortunately only time will tell, at least it seems to be more pessimistic than the readings from the app.

However, I now have a new thing to worry about. I noticed today that with not very much switched on, the shunt was reporting approximately a 10 amp discharge. I checked the output from the solar panels which was only a couple of amps. The only thing that could be producing that draw was the fridge. I continued to watch it for well over an hour and the discharge continued. So I disconnected the S+ signal from the Votronic 350 MPPT, click the fridge lit.
It seems that although I have set the jumpers for lithium the device hasn’t modified its algorithm. It has seen a little bit of sun, and also that the leisure battery is apparently fully charged (if it were LA) at 13.2volts. So, woopie I can run the fridge all day long from the leisure battery until it drops a volt or two. Which is obviously why my 600Ah lithium setup has been reducing so quickly. It obviously doesn’t do it in 30 minute bursts as it does or I thought it does, on lead acid. It obviously sees no variation from 13.2v which would be fully charged on LA and thinks I will keep going. My lithiums were at 50% but of course they do not reduce voltage at all until they falloff a cliff at about 5%. So, the wonderful Votronic MPPT which has saved me a fortune on gas while touring in Spain is not bright enough for a Lithium system. I have searched today for an explanation of the Votronic algorithm but cannot find it. So all I can do now is either disconnect the S+ and use more gas or leave it and run my batteries down if I am only sitting or only doing short distances.OK, I can fit a switch but then I have to think about it.

You could change the fridge from auto setting to gas to avoid the solar + activating the 12v, but you then have to remember to turn it back to auto if you want to benefit from the S+. Lenny's solution is more elegant and reliable of course.

 

[lonnie]

My whole reason for fitting two was Redundancy thereby giving me Resilience. I was heading off for a 90 day tour of Scandinavia where I intended to be off grid for most if not all of the time. Lithium is relatively new and developing fast and I didn't want to experience a battery failure in a country where any replacements would be mega expensive, if I could even find replacements. So two were a good insurance. In fact the system has been fantastic. I only experienced problems latterly as I was only doing a few miles each day, so my batteries were running down. In fact it was my Votronics Solar controller switching the Fridge to 12 volt as it thought my batteries were full because Lithium has a higher resting voltage than lead acid.
So, go for it and Don't forget to use Off Grid Solutions who are members on here and give a generous discount to members if you pre register with them. They also give an amazing amount of help and advice and regularly post answers on here. RogerIvy & nigelivy No connection other than I am just a very satisfied customer.

Thanks for the reply, that makes a lot of sense. I've been looking at OffGrid so will get in touch.

Have a great trip

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[RogerIvy]

RogerIvy I notice that my Victron B2B does not have a charged voltage and tail current setting like the solar controller does, so do you know how it decides when to go to absorption and float?

There is some useful info here.
Page 16 (section 4.4.3) is where you want to read.

 

[ChrisL]

There is some useful info here.
Page 16 (section 4.4.3) is where you want to read.

Thanks Roger, unfortunately the earlier B2B's don't have those additional settings, they appear to be only on the new 50 amp charger, I asked because my B2B doesn't quite charge to 100% it stops charging when the shunt reports -2ah left, the solar does take it to 100% though and the absorption and float voltages are the same. In practical terms it doesn't really matter but I was just curious.

 

[AdrianChen]

Thanks Roger, unfortunately the earlier B2B's don't have those additional settings, they appear to be only on the new 50 amp charger, I asked because my B2B doesn't quite charge to 100% it stops charging when the shunt reports -2ah left, the solar does take it to 100% though and the absorption and float voltages are the same. In practical terms it doesn't really matter but I was just curious.

Is it an earlier Orion? I think I set mine a little higher to compensate for some voltage drop in the cable, about 0.1v I think. Can't check now as I changed it to the xs version.

 

[royw]

its interesting the fogstar bms. current threshold for caputuring flow is 1 amp, They claim that no bms is more accurate yet roamer BMS is capable of capturing current flow above .4. of an amp. the victron Shunt default value is .1. of an amp so its very easy to see how long term parasitic draws will cause significant confusion on either of these two batteries.

 

[ChrisL]

Is it an earlier Orion? I think I set mine a little higher to compensate for some voltage drop in the cable, about 0.1v I think. Can't check now as I changed it to the xs version.

Yes it's the 30ah version, I only use about 30ah on average a day, so it's soon topped up again when driving to my next stop.

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[RogerIvy]

Thanks Roger, unfortunately the earlier B2B's don't have those additional settings, they appear to be only on the new 50 amp charger, I asked because my B2B doesn't quite charge to 100% it stops charging when the shunt reports -2ah left, the solar does take it to 100% though and the absorption and float voltages are the same. In practical terms it doesn't really matter but I was just curious.

What are your battery voltage settings in the Orion?
Suggest making it a little higher than the BMS OVP cutoff.

In reality as the battery is approaching 100% SOC pretty much most of your chargers should be reducing their output anyway.

 

[Onemanandhisdog]

Has anyone got a Drift Pro plugged directly in to the Victron Cerbo GX, that professes to not needing a shunt, but just wondering if it still gets out of kilter with the battery in the same way?

 

[RogerIvy]

Has anyone got a Drift Pro plugged directly in to the Victron Cerbo GX, that professes to not needing a shunt, but just wondering if it still gets out of kilter with the battery in the same way?

When plugging the DriftPro into a Cerbo the Cerbo reports exactly the same info as the BMS app

 

[Onemanandhisdog]

When plugging the DriftPro into a Cerbo the Cerbo reports exactly the same info as the BMS app

Hmm, so maybe not a good way to go then if its the BMS that misses small draws?

 

[AdrianChen]

When plugging the DriftPro into a Cerbo the Cerbo reports exactly the same info as the BMS app

That's good to know, thanks. I assumed the choice of monitor in the system setup menu would deal with that, and still allow use of the shunt.

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[Raul]

When plugging the DriftPro into a Cerbo the Cerbo reports exactly the same info as the BMS app

I assume that's for single battery.
What about daisy chain multiple batteries?
Does it take control over the charger/ inverter like seplos or JK inverter bms? Or, it just sends the data without control?
Thanks.

 

[BusyBuilder]

The more I read on here about charging systems, the less I know !