Battery Isolation Manager

[PGrougan]

I have a 2017 34PA that I am planning to upgrade to Battle Born litium batteries. (4) BBCG2 batteries will fit in under the step, giving me 400 aH.
According to Battle Born, I need to install a LI-BIM 225 to manage house and chassis batter charging. Has anyone made this conversion? or have experiance installing the LI-BIM in a gas Tiffin with 2017 electrical architecture?

Looking forward to your responses

[DavidEM]

The Li BIM 225 is a replacement for the BCC, BIRD or if you are lucky the Precision Circuits BIM 160 which allows a drop-in replacement with the Li-BIM 225. The other two BIM systems require some wiring finagling.

It cycles the chassis' DC system connection to the coach on and off every 15-20 minutes to limit current. With 400 Ahs of batteries I would be a little leery of it providing enough protection for the alternator, but if Battleborn says it is ok, then.......

David

[dssl]

You should install a shunt based battery monitor, which you will need to more accurately track your state of charge. This will also allow you to measure the current going into the batteries. Once you have a battery monitor installed you can determine your worst case alternator charging current, by having the battery a low state of charge. If you are likely to use any high amperage devices, like a microwave or AC...while under way then the worst case alternator draw is likely to be even worse. If your worst case current draw is around 50 amps or less an LBIM is not needed.

Another option besides an LBIM is a DC to DC charger, which is what I have on my 2015 32SA.

Another option you may want to consider is a couple of SOK 206ah batteries. They now make a version with a heater and Bluetooth. You could save some money and get a great battery with added functionality. I think the new SOK batteries even have a built-in battery monitor, so you could potentially live without the seperate battery monitor.

If you install an LBIM or a DC to DC charger you will need to stop your current merge relay from getting activated. I wanted my auxiliary start button to continue to work, so I called Tiffin and they were very helpful with instructions, plus they sent me some very helpful drawings and schematics for my 12v fuse panel which contains the merge relay. You basically cut the control wire to the merge relay and connect the wire from the auxiliary start button.

Good luck.

[PGrougan]

Originally Posted by dssl

You should install a shunt based battery monitor, which you will need to more accurately track your state of charge. This will also allow you to measure the current going into the batteries. Once you have a battery monitor installed you can determine your worst case alternator charging current, by having the battery a low state of charge. If you are likely to use any high amperage devices, like a microwave or AC...while under way then the worst case alternator draw is likely to be even worse. If your worst case current draw is around 50 amps or less an LBIM is not needed.

Another option besides an LBIM is a DC to DC charger, which is what I have on my 2015 32SA.

Another option you may want to consider is a couple of SOK 206ah batteries. They now make a version with a heater and Bluetooth. You could save some money and get a great battery with added functionality. I think the new SOK batteries even have a built-in battery monitor, so you could potentially live without the seperate battery monitor.

If you install an LBIM or a DC to DC charger you will need to stop your current merge relay from getting activated. I wanted my auxiliary start button to continue to work, so I called Tiffin and they were very helpful with instructions, plus they sent me some very helpful drawings and schematics for my 12v fuse panel which contains the merge relay. You basically cut the control wire to the merge relay and connect the wire from the auxiliary start button.

Good luck.

dssl,

Thankyou for the reply. In my research I have been coming to the same conclusion as you that a dc - dc charger may be the best solution to insure that my alternator is protected. Could you please share the drawings and schematics that Tiffin supplied? and if you know who you talked to at Tiffin, that would be helpful also.

[pvcampbell]

In my 2016 36LA, I replaced the lead-acid batteries in the step with 6 100AH LiFePO4 batteries from Battleborn. Unlike L-A batteries which must be installed outside living areas and vented to the atmosphere, Lithiums can/should be installed in living areas or in enclosed areas not exposed to extreme temperatures. So, I installed my new batteries in the first basement compartment behind the entry. Also installed in that location were the battery disconnect switches, Victron 500A shunt, Victron BMV-712 (Bluetooth version) battery monitor and solar controller.

Based on Battleborn's advice, I replaced the Tiffiin battery isolation solenoid with the Precision Circuits Li-BIM 225 rather than going to a DC-DC converter. With the battery monitor, I could watch the alternator draw on my smartphone while driving, and draws never exceeded about 55A. I didn't have any alternator problems with that setup, I transferred all that equipment to my current Newmar coach, and still no problems. Attached is a picture of my battery setup.

[PGrougan]

Originally Posted by pvcampbell

In my 2016 36LA, I replaced the lead-acid batteries in the step with 6 100AH LiFePO4 batteries from Battleborn. Unlike L-A batteries which must be installed outside living areas and vented to the atmosphere, Lithiums can/should be installed in living areas or in enclosed areas not exposed to extreme temperatures. So, I installed my new batteries in the first basement compartment behind the entry. Also installed in that location were the battery disconnect switches, Victron 500A shunt, Victron BMV-712 (Bluetooth version) battery monitor and solar controller.

Based on Battleborn's advice, I replaced the Tiffiin battery isolation solenoid with the Precision Circuits Li-BIM 225 rather than going to a DC-DC converter. With the battery monitor, I could watch the alternator draw on my smartphone while driving, and draws never exceeded about 55A. I didn't have any alternator problems with that setup, I transferred all that equipment to my current Newmar coach, and still no problems. Attached is a picture of my battery setup.

pvcampbell,

The Tiffin battery isolation solenoid is located in the first bay on the driver's side behind a buss-bar bridge next to our pure sine inverter. It is pretty tight quarters to get to it.

Was the replacement of the solenoid to the LI-BIM 225 pretty straight forward? Without unfastening and moving the buss I don't have a visual of the solenoid.

[pvcampbell]

Originally Posted by PGrougan

pvcampbell,
Was the replacement of the solenoid to the LI-BIM 225 pretty straight forward? Without unfastening and moving the buss I don't have a visual of the solenoid.

It's been several years since I did the work on the Tiffin, so my memory is a little foggy. My solenoid was located in an inaccessible location. I have an old fuzzy photo of that, but don't recall exactly the location. I do not have a photo of the new Li-BIM 225 installation.

As I recall, I found a nearby location with easy access to mount the new BIM.
I then removed the small solenoid-actuator cables and spliced those to new wires running to the new BIM. I then made new (probably 4 gauge) cables with lugs on each end, and connected those cables to the (now dead) solenoid lugs and to the new BIM. The old solenoid stayed in place with its only purpose being lugs for the extended power cables.

[dssl]

Originally Posted by PGrougan

dssl,

Thankyou for the reply. In my research I have been coming to the same conclusion as you that a dc - dc charger may be the best solution to insure that my alternator is protected. Could you please share the drawings and schematics that Tiffin supplied? and if you know who you talked to at Tiffin, that would be helpful also.

I don't remember who I spoke to at Tiffin. If tou pm me your email address I can send those drawings. It really wasn't complicated. Assuming your panel is the same. I just cut the wire to the relay control wire connected the wire from the aux start switch and hooked them together. The only tricky thing is there is one wire going to the switch and one coming back, you need the one coming back. You end up with 2 wires to cap, one that went to the merge relay and one that comes in from the aux start button.

I have a Victron orion 30 amp unit. One down side is it throws off some heat. I ended up installing one of these fans underneath it to increase the air flow and prevent it from reducing its output
https://www.amazon.com/gp/aw/d/B07RMJC9NT?psc=1&ref=ppx_pop_mob_b_asin_title

An LBIM does have the advantage of not throwing off any significant heat.

There is a chance you don't need anything. For me I have 824ah and run my AC off the batteries when it gets hot off my Victron MultiplusII 3k inverter, so although I never checked my max draw fairly sure it would be a problem. As an example Vince Sheetz has 600ah of lithium and he determined that his max alternator draw was 45 or 50 amps and decided he was okay, particularly since be has plenty of solar.

[twinboat]

Once located, you can leave your isolation solenoid in place and use it as a junction point for short cables to the L-BIM.

Then you can disable the isolation solenoid, by moving the small activation wires to the BIM.