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

 

[osuallen]

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.

We are there starting on the 10th. Is that your schedule?

 

[AbdRahim]

We are there starting on the 10th. Is that your schedule?

17th

 

[Neal]

Another point of interest on this topic is for those new to LiFePO4 to remember it can take a much higher charge rate, up to 300A I believe. So you can't put the 50A in your head like non Li batts. Granted, you have to keep in mind wiring and other components, but the charge rate is something to be aware of that can benefit you.

 

[AbdRahim]

Another point of interest on this topic is for those new to LiFePO4 to remember it can take a much higher charge rate, up to 300A I believe. So you can't put the 50A in your head like non Li batts. Granted, you have to keep in mind wiring and other components, but the charge rate is something to be aware of that can benefit you.

Not sure what that means, since the coach is limited to 50A and mine 42A on thegenerator. Or am I missing something.

 

[Kevin D Pem]

Not sure what that means, since the coach is limited to 50A and mine 42A on thegenerator. Or am I missing something.

What it means is without a method to regulate the current, a li battery acts like a dead short!

 

[Cambria]

300AH RV Boat Lithium Ion | Modbus DATA Port | Bluetooth | LiFeBlue Battery

LiFeBlue 300AH Battery The Smartest Bluetooth Lithium Ion Battery specially designed for RV and Marine Use!

www.lifebluebattery.com

"Our "drop in" replacement battery is unlike any other on the market. The automatic BMS system offers 10 different protection modes including, over and under voltage, over and under temperature, over current, short circuit, fault events and more. We have specially designed the BMS for RV and Marine use where there are multiple charge sources with different charge profiles and voltages. Our battery can be charged directly from ANY PV solar controller, ANY inverter/charger and with properly sized wiring, ANY alternator can be used without the need for a special regulator or DC-DC converter. You do not need a special "Lithium" capable charger. Some multi-stage converters will not work but any standard CV converter that can output 13.8 Volts or higher will work."

 

[Wemustrv]

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.

Man I hate acronyms that are not used properly. I am sorry but it drives me nuts. BIM= Building information modeling, Bureau of international Maritime, basic initialization module, binary input/output module. I found nothing relating to battery. Proper method of using an acronym Oh My God (OMG) spell it out the first time used and from there on out use the abbreviation. Sorry for my rant but why can't we jus spell it out? I just spent 5 minutes trying to figure out BIM and still do not know what it is. I guess I am too old school and unintelligent to deal with these.

 

[Rich W.]

Battery Isolation Manager:

The Battery Isolation Manager (BIM) isolates the two battery systems, Chassis & Coach, in a Motorhome. This prevents loads in one system from discharging both. It also connects the two battery systems together during charging. Both batteries are charged if either is being charged. The Coach Battery is charged while driving down the road.

Battery Isolation Manager | Precision Circuits Inc

The Battery Isolation Manager (BIM) isolates the two battery systems, Chassis & Coach, in a Motorhome. This prevents loads in one system from discharging both. It also connects the two battery

www.precisioncircuitsinc.com

And should the BIRD come up in conversation, here’s this:

Bi-Directional Isolator Relay Delay – Intellitec Products, LLC

intellitec.com

 

[redbaron]

Sorry for my rant but why can't we jus spell it out? I just spent 5 minutes trying to figure out BIM and still do not know what it is. I guess I am too old school and unintelligent to deal with these.

I had to laugh at this, as I remembered a reddit post a few years ago. It was a challenge of how long of a sentence can one write using common texting shorthand and other acronyms. Here is the result:

GAS 2U!

DQMOT, BSF IDK WCA 2TXT W/LOA.

IYO, ITS EZ &PDQ... IDTS.

IMHO, ARE =ADIH. TBH, FUBAR &2M2H. GIAR, PLZ! KISS.

.02

RX

---

Translation:

Greetings and Salutations to you!

Don't quote me on this, but seriously folks I don't know who cares anyway to text with lists of acronyms.

In your opinion, its easy and pretty darn quick... I don't think so.

In my humble opinion, an acronym rich environment is another day in hell. To be honest. its *fouled* up beyond all recognition and too much to handle. Give it a rest, please! Keep it simple, stupid.

 

[AbdRahim]

I had to laugh at this, as I remembered a reddit post a few years ago. It was a challenge of how long of a sentence can one write using common texting shorthand and other acronyms. Here is the result:

I think lawyers cornered the market on run on sentences. No offense to that profession, but I once took a racing course, and the first sentence of the part of the contract that released the school from responsibility for injuries, etc. was almost half a page long. I cracked up laughing about halfway through the sentence.