Victron BSC IP22 12/30

[JohnU]

A configuration question:

When I charge my 280ah battery should I use the Victron in Charger or Power Supply mode set to 14.4 volts and let the BMS control the charging?

I will be adding a Victron Battery to Battery for the motorhome and probably have the same question. I haven’t looked at the B to B config yet.

Any ideas?

 

[Bob B]

Most people with go with the standard recommendation that the BMS is for battery protection and should only be used for shutting things down when there is an emergency situation.

I'm a little more flexible with the way I view it .... I just want to make sure there are redundant protections in place for things like temperature and over and under voltage.

What BMS will you be using?

 

[JohnU]

I am using the overkill 4 cel 120a

 

[JohnU]

I am using the overkill 4 cel 120a

Normally I will be using the Victron MPPT with PV on my motorhome roof to charge. Only using the BSC 12/30 when on site on mains power to quickly charge. But would imagine I have the same question with the Victron B to B between my vehicle battery and my new Lithium Leisure battery.

 

[Bob B]

I am using the overkill 4 cel 120a

I wouldn't use a FET based BMS like that for day to day control of charge cut-off.

I am using a contactor based BMS and controlling multiple small relays / SSR's that actually turn equipment on and off. I'm trying to avoid switching battery power except when doing it with a manual switch.
It's a lot harder to do it this way ... and not for everyone.

 

[JohnU]

That’s what I was thinking set the charger at power supply to 14.2 volts. Set the MPPT to lithium mode. Not sure on the B to B yet, haven’t open the box.

Do you think the 14.2 volt set on the charger is ok?

 

[JohnU]

That’s what I was thinking set the charger at power supply to 14.2 volts. Set the MPPT to lithium mode. Not sure on the B to B yet, haven’t open the box.

Do you think the 14.2 volt set on the charger is ok?

Sorry read your reply wrong. You wouldn’t use the BMS to control the charging?

 

[Bob B]

It's hard to find a converter setup for an RV that is any good for lithium. Best is to try to find one where you can specify bulk and float voltages. You should be able to do that with some of the Victron equipment .... This is also why many use the inverter / chargers because they have more ability to program them.

No, I wouldn't use that BMS to control charging on a daily basis.

 

[JohnU]

It's hard to find a converter setup for an RV that is any good for lithium. Best is to try to find one where you can specify bulk and float voltages. You should be able to do that with some of the Victron equipment .... This is also why many use the inverter / chargers because they have more ability to program them.

No, I wouldn't use that BMS to control charging on a daily basis.

 

[JohnU]

What would you set the bulk and float voltages to?

 

[HRTKD]

I have the Overkill Solar 4s 120 amp BMS. I don't use it to control charging either. Most of my charge devices are programmable and I have them set to a lower voltage than the default. I'm currently set to 14.2v for bulk mode.

The idea that the BMS is the last line of defense is common here on the forum. Mine is set to cut off charging at 14.6v. It's there in case something really goes wrong. The BMS is working quite well and I have no complaints.

 

[Bob B]

What would you set the bulk and float voltages to?

There's a lot of opinions about that .... and I really don't have one.

I would read thru some of these threads. https://diysolarforum.com/search/488105/?q=bulk+and+float&o=relevance

 

[JohnU]

My Victron 12/30 have this configuration for lithium.

 

[Bob B]

I would reduce that Storage to maybe 13.3 and put a float of around 13.4 or so .... others may have more refined recommendations.

 

[Bob B]

The problem with going this route is that it is going to take longer to charge the batteries. If you need to get some charge into them in a hurry .... maybe running a generator to charge .... you could go to a higher bulk and eliminate the float again just for that short term.

 

[JohnU]

I would reduce that Storage to maybe 13.3 and put a float of around 13.4 or so .... others may have more refined recommendations.

What’s your cell delta with a 13.4 float charge?

 

[Bob B]

What’s your cell delta with a 13.4 float charge?

I'm not sure what your question is?
I have my BMS set to maintain no greater than 30mv difference between cells.

 

[lexio]

What’s your cell delta with a 13.4 float charge?

13.4v 0.001v other bank 0.002v 2*280ah lishen if i charge to 14.1v (bulk) 0.035v -- 0.040v daly 200amp/h bms 40 amp/h charge per battery

 

[JohnU]

I'm not sure what your question is?
I have my BMS set to maintain no greater than 30mv difference between cells.

Thanks

 

[JohnU]

I’m still confused. The Victron BSC 12/30 charger has three levels:

Absorption Voltage
Float Voltage
Storage Voltage

How do we set these levels when the Victron MPPT levels:

Bulk Voltage
Absorption Voltage
Float Level

Anybody used both these devices together?

How do we set these up?

I looking at using the charger when I’m parked up in my Motor home on mains hook to charge the battery quickly.