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Winston DIY LiFePO4 battery not charging from Votronic VCC 1212-90 battery to battery charger??

nigelivy

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Joined
Dec 7, 2020
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Hi Folks

I've just recently put a new DIY LiFePO4 battery into my campervan. I used 200ah Winston battery cells with the 123 Smart BMS.

I'm trying to charge the battery with a combination of:
1) Votronics VCC 1212-90 battery to battery charger
2) Epever XTRA4210N MPPT solar charge controller

The battery to battery charger and solar charge controller do not charge the battery at all, although they are both receiving the correct input.

The battery to battery charger is getting current from the alternator and it starts up (fan spinning, etc..), starts outputting current to the LiFePO4 battery and then after about 5 seconds it turns off for a few seconds and then starts the process again. It keeps doing this indefinitely and never charges consistently.

The solar charger receives input from the panels and outputs it to the battery, but the BMS does not report any charge from the solar charge controller.

Does anyone know why they'd be doing this? Is it possible that the BMS is disconnecting the charge?
 
It's possible, did you read this manual for it?

I see several settings in there which could lead to the BMS disconnecting. Do you also have a voltmeter and amp probe for side monitoring while you're troubleshooting what is going on?
I've had a look through the manual for the BMS and don't see that any of the conditions would be met that would cause the BMS to turn charging off.

The temperature in the campervan is around 20 degrees celsius and the battery cells were sitting around that temp, so well within the temp max/min thresholds.

The battery cells were around 3.4v each, so well above the v-min of 3v and well under the v-balance of 3.6v.
I wonder if it's possible that the battery to battery charger pushed the voltage of all the cells above 3.6v so the BMS stopped charge? Although I have the 123 Electric Smart Relay installed, so I would think that the BMS would activate the relay, which I would have heard if it had opened to relay to disconnect the charge?
 
I've had a look through the manual for the BMS and don't see that any of the conditions would be met that would cause the BMS to turn charging off.

The temperature in the campervan is around 20 degrees celsius and the battery cells were sitting around that temp, so well within the temp max/min thresholds.

The battery cells were around 3.4v each, so well above the v-min of 3v and well under the v-balance of 3.6v.
I wonder if it's possible that the battery to battery charger pushed the voltage of all the cells above 3.6v so the BMS stopped charge? Although I have the 123 Electric Smart Relay installed, so I would think that the BMS would activate the relay, which I would have heard if it had opened to relay to disconnect the charge?

That's why if it were me, I'd plug on a standalone voltmeter and amp probe onto the battery leads and try to watch real numbers as I was playing with the chargers. Also to isolate, I would disconnect the adjacent charger while I was testing with one of each charger just to rule it out of the testing for that charger.
 
I think you are posting the same question on UK van forums. With the Votronics 12 12 90, trying to pull in excess of 90 amps, (note thats the output current, the input will be higher), from the alternator in a van of your age is not possible. The stock alternator is perhaps 120A max at high revs. At engine idle there wont be enough spare to drive the DC converter. I suspect its cutting out due to low voltage. It can be programmed for a lower output but even then the current taken may be too much for the alternator performance and reliability. Most vehicle alternators cannot deliver more than 50% of the maximum rating continuously without reliability problems. You say you are using D+ as a control system. With your van, non smart alternator, voltage sensing should be enough. If the overload of the alternator is occuring as I suspect, the D+ signal will be all over the place.

You dont specify any update of the existing cables and fuses/breakers or how the modifications are integrated into the original electrical control system, there could be issues there.

You do make the comment on the other forum that the shore powered charger works OK, this this suggests that the battery pack is accepting charge at a lower current level, so you have some functionality.

Problems with the Epever solar controller may be down to setup error.

Both the solar controller and the 12 12 90 may need the temperature sensor connected to work correctly when the lithium profile is selected.

I suggest working on one charging system at a time and measuring voltages and currents in the system as a first step to resolving the problem. Its far better when trying to resolve problems on DIY forums to separate the issues and deal with each element separately.
If you do not own one at the moment a clamp DC current measuring meter is a necessity when commissioning a systen like yours, example,

I assume that the Winston battery pack has been top balanced and a discharge and charge cycle has been completed to ensure its functioning OK. At the moment it sounds as the system has been put together without evaluating each part separately for correct performance. Good luck with your investigation.

Mike
 
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Show us the settings/parameters for the BMS. There was another forum member that had an odd problem with charging that was easily solved once we saw what the BMS saw.
 
I think you are posting the same question on UK van forums. With the Votronics 12 12 90, trying to pull in excess of 90 amps, (note thats the output current, the input will be higher), from the alternator in a van of your age is not possible. The stock alternator is perhaps 120A max at high revs. At engine idle there wont be enough spare to drive the DC converter. I suspect its cutting out due to low voltage. It can be programmed for a lower output but even then the current taken may be too much for the alternator performance and reliability. Most vehicle alternators cannot deliver more than 50% of the maximum rating continuously without reliability problems. You say you are using D+ as a control system. With your van, non smart alternator, voltage sensing should be enough. If the overload of the alternator is occuring as I suspect, the D+ signal will be all over the place.

You dont specify any update of the existing cables and fuses/breakers or how the modifications are integrated into the original electrical control system, there could be issues there.

You do make the comment on the other forum that the shore powered charger works OK, this this suggests that the battery pack is accepting charge at a lower current level, so you have some functionality.

Problems with the Epever solar controller may be down to setup error.

Both the solar controller and the 12 12 90 may need the temperature sensor connected to work correctly when the lithium profile is selected.

I suggest working on one charging system at a time and measuring voltages and currents in the system as a first step to resolving the problem. Its far better when trying to resolve problems on DIY forums to separate the issues and deal with each element separately.
If you do not own one at the moment a clamp DC current measuring meter is a necessity when commissioning a systen like yours, example,

I assume that the Winston battery pack has been top balanced and a discharge and charge cycle has been completed to ensure its functioning OK. At the moment it sounds as the system has been put together without evaluating each part separately for correct performance. Good luck with your investigation.

Mike
Thanks for the advice, Mike! I've adjusted the Votronic 12 12 90 to use the minimum input and output settings and it has helped. The charger now seems to only cut off when the engine is idling, so I think you are correct in that the alternator is obviously not powerful enough to run this charger at it's maximum capacity.

To integrate the charger into the van, I put a relay between the ECB & the Votronics 12 12 90, which is activated by the D+ as well. This cuts the line from the DIY LiFePO4 battery to the ECB when the engine is running. I guess this could be erratic if the D+ is not consistent, as you mentioned above.

I'll monitor the amperage and voltage of the system and keep you posted.
 
Show us the settings/parameters for the BMS. There was another forum member that had an odd problem with charging that was easily solved once we saw what the BMS saw.
Hi Jim. These are the settings I have on the BMS:
E9904176-02A3-4A11-A70E-CA9699E673E1.png808AB550-1E2E-44A1-8DEF-7978B318043F.png
CDAC5336-1D3C-48DE-A381-582FDAF809A2.png
02B660A7-8ECA-4A6A-9FFA-931685430B99.png

I believe that the BMS is working fine and that it is the alternator/battery to battery charger that’s the problem, not the BMS.
 
Seems you are making progress. As I suggested in my earlier comment, even setting the 12 12 90 at the lowest current from the alternator, the draw may still be too high, at around 65 amps. If your alternator is specified at 120 amps , that's the max at high revs, at idle it will be much less. Even with a 180 amp alternator, taking more than around 60 amps will compromise the alternator reliability. I don't know what engine you have in the van, I guess a 2.8 Fiat.. it may be possible to fit a higher output alternator providing the drive belts can handle the extra power and a suitable alternator with the same dimensions and fixings is available.. it is possible for a starter/alternator rebuild shop to build a 'special' to match your engine.

In addition to lacking power your alternator may nor be at its best if it's several years old. Giving it a hard time may kill it. I suggest disconnecting the engine charging until you fully test or replace the alternator.
Out of interest I tested the output of a 180 amp alternator at tickover and there was about 85 'spare' after the engine electrics had their quota. Consider that there will be a need for ac or heater fans, lighting, and other additional van loads, they will reduce the 'spare' even lower. I feel thar around 60 amps is the most you should aim for with a 180 amp alternator. Most up fitters guides suggest a limit of 50 amps for Europe vans.

How are things with the Epever controller, any progress there?

If the bms display is correct it seems the battery is near full charge, if you drop capacity by applying load does the Epever starts operating?

Mike
 
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Seems you are making progress. As I suggested in my earlier comment, even setting the 12 12 90 at the lowest current from the alternator, the draw may still be too high, at around 65 amps. If your alternator is specified at 120 amps , that's the max at high revs, at idle it will be much less. Even with a 180 amp alternator, taking more than around 60 amps will compromise the alternator reliability. I don't know what engine you have in the van, I guess a 2.8 Fiat.. it may be possible to fit a higher output alternator providing the drive belts can handle the extra power and a suitable alternator with the same dimensions and fixings is available.. it is possible for a starter/alternator rebuild shop to build a 'special' to match your engine.

In addition to lacking power your alternator may nor be at its best if it's several years old. Giving it a hard time may kill it. I suggest disconnecting the engine charging until you fully test or replace the alternator.
Out of interest I tested the output of a 180 amp alternator at tickover and there was about 85 'spare' after the engine electrics had their quota. Consider that there will be a need for ac or heater fans, lighting, and other additional van loads, they will reduce the 'spare' even lower. I feel thar around 60 amps is the most you should aim for with a 180 amp alternator. Most up fitters guides suggest a limit of 50 amps for Europe vans.

How are things with the Epever controller, any progress there?

If the bms display is correct it seems the battery is near full charge, if you drop capacity by applying load does the Epever starts operating?

Mike
Thanks for the advice, Mike. I really appreciate it! That's been very useful. I think you are right that the alternator is not up to the task. My van is the Fiat 2.8tdi with a 120a alternator. I'm not sure if it's the original alternator that came with the van or if it was replaced at some point. The van is 10 years old, so could be original.

As the B2B charger is less than a month ago and have only just fitted it, I'm going to try and exchange it for a lower amperage charger. I went for the higher amperage because there wasn't a big price difference and I thought it would be good to have space for expansion, but clearly this wasn't the right approach.
I'm also going to look at changing the alternator for something more substantial (even if I exchange the B2B charger).

I have the Epever working now. I went through the settings again and read up on it and adjusted a few things. I also cycled the battery a couple of times and tested the Epever at a lower SOC and it seems to be working fine. Weather permitting, I'll test some more, but hopefully that's all good now.

Thanks again for the help!
 
Thought I'd update you on what I landed up up doing for this issue that I was facing. I had wanted to change my alternator at some point, so decided that I would just go ahead and do that.

I bought a 160A alternator and fitted that on my van and has pretty much solved the issue. The charger now runs constantly and doesn't stop/start when the vehicle is idling. I spent quite a bit of time interacting with the owner of Roadpro (who I bought the charger from) and he has assured me that the charger will not damage the alternator and it stopping/starting was to ensure that it did not draw too much for the alternator to handle and also that that is designed behaviour for the charger, so it would not have problems either.
Nevertheless, I changed the alternator anyway because I felt that my previous 120A alternator wasn't powerful enough for what I needed anyway and it has solved the issue. I have cycled my LiFePO4 battery a number of times now and charged it from low SOC and not had problems.

Thanks again for all your input!
 
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