daveybdublin avatar image
daveybdublin asked

VE Lithium Battery Bank, Which BMS to Use?

Hi All,

I appreciate that this question may come down to preference, but I would greatly appreciate anyone's input on this if possible. My dad and I are currently installing the VE setup I've purchased for my liveaboard, which includes:

3 x 100ah Lifepo4 batteries

1 x Multiplus 12/3000/120

1 x BMS 12/200

1 x BMV 712 shunt

2 x Power In Bus bars

1 x Cerbo GX & Monitor

1 x Standard 105ah lead acid starter battery

70amp alternator

The Victron setup above was recommended to us by the agent who I purchased it from. Since then we have done a good bit of research on the Victron setup, and we are now questioning whether the BMS 12/200 is the best option for our setup... Would anyone recommend the Smart BMS CL 12/100 and or the VE.Bus BMS along with the Cyrix Li Ct?

The Smart BMS does not appear to limit the current draw of the house batteries which the BMS 12/200 does appear to do. The Smart BMS also appears to offer better protection to the starter battery..

Can anyone weigh in on their experience or opinion of these BMS options?

Cheers, David

MultiPlus Quattro Inverter ChargerBMSVE.Busve.bus bms
1 comment
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martins avatar image martins commented ·

I am in the middle of a similar design and like you I am struggling with the choice of BMS. The YouTube video referenced may help. As the video points out the BMS 12/200 can limit the current from the alternator ( a critical step to not burning out the alternator) but does so on the negative side. The disadvantage of the 12/200 and the CL 12/100 seems to be the inability to regulate charge voltage.
Would be a big help if Victron supplied some improved guidance on which BMS suits which application as we have everything from the small BMS to the Lynx Smart BMS to choose from.
would be great to hear from others.

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5 Answers
sv-drumbeat avatar image
sv-drumbeat answered ·

I'm just finishing months of researching before making the leap in a few days myself, so no real-world Victron experience yet. From my studies and vendor discussions, it seems that one of the key components of getting the VE.Bus BMS to work is to have another VE.Bus device, such as your Multiplus. VE.Bus BMS seems to be the one that enables the most functionality from other Victron components.

A lot depends on the output of your alternator, which is only 70A, vs the size of the bank. The Li-Ct will close the charging relay and attempt to charge your 300Ah bank as quickly as it can which can burn out the diodes in your alternator without limiting it. I'm sure you alredy know this, but if you're using the Li-Ct there needs to be a load-dump (such as an AGM start battery) wired in on the alternator/starter side of the Li-Ct in case the current to the lithiums is cut by the BMS. There is a built-in current limiting function in the BMS 12/200 via 80% of fuse's (max 100A) rating. You'll need to check your alternator manual for maximum continuous current and select your fuse appropriately on the BMS 12/200. I don't believe that the VE.Bus BMS will attempt to current-limit your alternator (someone please correct me if I'm wrong here). It's my understanding that you will also need other gear like Battery Protects x2 etc. if you go the VE.Bus BMS route.

There is a great webinar from Victron available, "Victron Q&A Webinar 1 - Using your Alternator to charge Lithium" which will likely answer most of your questions on this topic:

There are several ways to limit the current your alternator puts out. The video goes into a few of the pure Victron options in detail. If your alternator is externally regulated, you might be able to limit the current or de-rate it right from it's own regulator such as the Balmar MC-614-H.

Hope this helps, and keep us posted. Best of luck!

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drlbradley avatar image
drlbradley answered ·

If it helps, I plan on having a Smart Battery Protect on the 12v load side of batteries, and a Cyrix Li-Ct on the charge side, both controlled by the Ve.Bus BMS. I'm not inputting directly from the alternator though, I'm using an Orion DC-DC 30A from the vehicle battery to charge (via the Cyrix)

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Paul B avatar image
Paul B answered ·

I presume your are asking what BMS to put on your batteries, if this is the case we use

123 smart BMS this has bluetooth and is very good and quite easy to install as well

and Chargery BMS, this is well priced but harder to setup.

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paul-2 avatar image
paul-2 answered ·

The alternator problem is on the other side. If the BMS opens up while under charge, the resulting surge can damage the diodes.

Also, the bms 12/200 is limited to 200 amps. On a mulitplus 12/3000 that is only 80% of the capacity. Also because there is no communication on ve.bus the inverter won't have any information for limiting charge or discharge. The ve.bus bms with an LI-CT and a Battery protect is a better system combination.

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hoeken avatar image
hoeken answered ·

Just an FYI, if you use VE.Bus BMS and a Multiplus together, you will not be able to turn the inverter on/off from the app or through the Cerbo. Only with a Digital Multi Controller panel, or the switch on the inverter. It's a really annoying bug and you can see there are multiple threads about it:

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