Question Li-BIM vs. DC-DC charger?

[Neal]

I learned from another thread asking about a BIM for LiFePO4 batteries where we typically use a Li-BIM to manage alternator charging of the batteries of the DC-DC charger such as the Victron unit below:

https://www.victronenergy.com/dc-dc-converters/orion-xs-12-12-50a-dc-dc-battery-charger

I'd like to continue the discussion and education, i.e. my question is how does this work and is it a suitable replacement for the Li-BIM. What is the functional difference between a BIM and DC to DC charger? Also in the discussion was mention of needing two of these. I'm curious why and where such as are they side by side behind the cord reel where the BIM is and what is the wire path. I think the BIM has a wire coming and going out so I'm not aware of two paths.

Educate me and others that may need or want to learn of this architecture.

 

[redbaron]

LiBIM utilizes a timer method, connecting for 15 minutes every 35 minutes. The max amps it will allow are up to 200Amps, based on wire size.

The DC-to-DC Charger will limit the draw to it rated capacity or less, but otherwise remains connected at all times.

It is also a one-way device--functioning like a diode.

Multiple DC-DC Chargers can be used if you need a faster charge, paralleling 2 50amps gives you up to 100 amps of continuous charging.

Other provisions need to be made if you want to enable the Boost feature.

 

[MemoriesByTheMile]

I haven’t looked into this Victron Orion device before but really like it after my first review of features and specs.
The LiBIM that we have will just cycle the charging on and off, as Redbaron said.
But this Orion device has low temperature shutdown to avoid charging batteries below a certain temp.
And if the rest of the system is Victron it appears that it ties into remote adjustment and monitoring.

 

[Neal]

I'm all Victron so I'm very interested in this and as I mentioned in another thread I don't like arriving less than 100% SOC and it's important if going off grid and you want to arrive obviously at fully charged. I don't know if this is a simple swap out of the Li-BIM or if it's more involved. I also sent a message to Solar Energy Systems (SES) to see what they say and if it's not a simple swap I may have them do it. If Victron 330's keep dropping in price I may also get the additional 4 I'm prewired for from my install as well. But this DC-DC converter looks nice and if it's smart it's far better than the dumb (timer based) Li-BIM.

 

[Neal]

I sent an email to SES this morning, just got a reply, on Memorial Day nonetheless. Always impressed with them!

Li- BIM pros
1) 200 amp pass thru charging , intermittently 15 min cycle so ultimately 100 amp constant for calculation
2) watching the chassis battery as well and if house battery is full enough, it will charge your chassis battery for an hour should it get too low,
3) helps alternator to cool down by cycle charging

LI-BIM cons
1) cannot control when it charges

XS 50
Pros
1) controlled charge at 50 amps at desired voltage, 50 amp per XS, no matter how low chassis is
2) communication to cerbo and VRM

Cons
1) will not charge chassis battery
2) will not give the alternator a break
3) will need 4 XS 50 to get full 200 amp from
Alternator to house battery.

 

[AbdRahim]

I'm all Victron so I'm very interested in this and as I mentioned in another thread I don't like arriving less than 100% SOC and it's important if going off grid and you want to arrive obviously at fully charged. I don't know if this is a simple swap out of the Li-BIM or if it's more involved. I also sent a message to Solar Energy Systems (SES) to see what they say and if it's not a simple swap I may have them do it. If Victron 330's keep dropping in price I may also get the additional 4 I'm prewired for from my install as well. But this DC-DC converter looks nice and if it's smart it's far better than the dumb (timer based) Li-BIM.

Heading to solar energy in two weeks. Considering Li. Four 330’s. Wow! Will be discussing all of the possibilities with them. Hope I understand it all well enough to articulate.

 

[Neal]

I'd email them and start the dialog now, get a quote, they will help you figure out what you want. I'm 100% on board with LiFePO4 - love them! They are great to work with. They will need to schedule you as well so another reason to start that dialog soon.

 

[Kevin D Pem]

Does the LiBIM boost the voltage to the LiFePo4?

If not the DC to DC converter will! So can you put the converter in line with the bim!

Ultimately the DC to DC converter can supply the proper supply voltage to the BMS.

You have more questions to ask your supplier!

 

[AbdRahim]

I'd email them and start the dialog now, get a quote, they will help you figure out what you want. I'm 100% on board with LiFePO4 - love them! They are great to work with. They will need to schedule you as well so another reason to start that dialog soon.

Already have appt. Talked a bit on the phone and got-an estimate. OUCH!

 

[Neal]

Keep in mind LiFePO4's should last you 10+ years