Battleborn lithium upgrade advise

[zombiewoof]

I had 2020 40IH and now have a 2021 Bus. I boondock quite a bit. The 40IH had three solar panels, lead acid batteries and propane. It boondocked very well with this setup. The 2021 Bus (all electric) has 810 A-hr of lithium and three solar panels (510 watts). The lithium batteries are awesome. I would never go back to lead acid (though they are pricey). I recommend you look at the 270 A-hr batteries. I know they are costly but they fit into the battery compartment very slick (the slide out tray is removed since it is no longer needed). Also the larger batteries require less wiring and fewer connections per A-hr capacity. A win win for complexity and potential points of failure. The limitation on the batteries is the Magnum inverter. It can only charge the batteries at 117 amps max. The batteries could easily charge at 300 amps which would make recharge times much shorter. The 510 watts of solar (three panels) is not enough. I should have opted for the six panel option. I intend to upgrade to that soon. Also note the lithium batteries take several hundred pounds off the weight on the front axle.

[Dbpublic]

I am totally interested in your outcome and a list of components you went with.


I just got off the phone with Battle Born, and they stated if we install the lithium batteries we can program the Spyder to charge them, but then we will need a trickle charger or something for the chassis battery.



Meanwhile, I am trying to figure out if we need a BIM like our old rig and what other components make sense to get the most out of the batteries.

[Maverick71]

Unfortunately this project was put on hold as the guy I was working with trying to figure out the best way to handle the spyder bypass has gone mia. I’m still very interested in upgrading before the winter desert season as we plan on doing a lot more boondocking. I’m just under 2 hours from Reno so it might be time I take a drive up the hill and sit down with the team at battleborn to see what my options truly are.

Outside chance anyone on here is from northern or central California and has done the exact upgrade I’ve been thinking about, I’d love to get your contacts information

[Rewarder1]

Pay a couple of dollars and get the internal heaters for the Battle Borns. Also change the charger to a lithium charger. Should charge to 14.6 volts. You will have to isolate you lithium from the alternator so you don’t burn it up. Add a dc to dc charger. All this is explained on you tube. Do your homework to see what your needs are. Well worth the up grades. mccombjim3@gmail.com

[Dbpublic]

Maverick 71 I am in Santa Cruz. I will be working on this project (4 Battle Borns) over the long weekend on our 2021 Tiffin Allegro Red. I assume it's the same Spyder, which is the issue. I will try and get a wiring diagram from Tiffin so I know where to place the BIM and how to manage the chassis batteries.

Some time ago, the couple from the YouTube channel, You, Me and the RV installed theses batteries and did a segment. They seem to work for them and they do a fair amount of boondocking

[MR.Roboto]

Originally Posted by Rewarder1

Pay a couple of dollars and get the internal heaters for the Battle Borns. Also change the charger to a lithium charger. Should charge to 14.6 volts. You will have to isolate you lithium from the alternator so you don’t burn it up. Add a dc to dc charger. All this is explained on you tube. Do your homework to see what your needs are. Well worth the up grades. mccombjim3@gmail.com

I have a Victron 12/12 18AMP DC/DC I would like to install. How to isolate the alternator? I can't find any wiring information or diagrams.

[RonAz]

I spent about an hour on the phone with Spyder Controls discussing alternator charging of lithium batteries. The outcome was mostly that they could probably write the software to make my suggestion work, but Tiffin would have to request it.
If you think of a DC-DC charger as another generator, then the way to protect the alternator and preserve the full Spyder functionality is already there. With the MH engine running the Spyder would disable shore power charging, open the merge solenoid, and allow the alternator to provide power
to the chassis batteries. The DC-DC charger would not go through the merge solenoid, but would have a new lead from the chassis side of the merge solenoid or the chassis battery.
This would all be automatic to the owner. With the increase of lithium installs, I believe that the alternator needs to be protected to operate in its safe continuous output of approximately 50% of rated output. This especially applies during morning dry camping start up with batteries at a low state of charge. The batteries at this point can accept the full output of an alternator. The problem comes from the alternator running at high output with the engine at idle speed during start up, retracting slides and jacks, and driving slowly from the camp site. The alternator is turning too slow to get adequate cooling from its fan to keep it from over heating in this scenario.
This is just my opinion and your thoughts and experience may vary from mine. A Tiffin employee suggested that the long cable runs and switches may add enough resistance to keep the alternator below full output levels. As time goes by, I think that we will find what works and what doesn't.

[Isaac-1]

I just bought a Renogy 50 amp DC-DC charger with integrated MPPT solar controller, overall an impressive device (with a few shortcomings) for under $250. It acts as a DC-DC charger for the Lithium batteries, doubles as an MPPT solar controller for up to about 400 watts worth of solar panels (limited to 25VDC input voltage), and also mostly eliminates the need for a battery isolator. Once the house Lithium battery is fully charged it verses the flow on the alternator input stud to charge the engine starting battery with any excess power it is seeing, in addition to this a number of the settings can be customized with the optional $30 BT-2 bluetooth dongle, these include user defined charge profiles, and selectable alternator charge rates of 10,20,30,40,50 amps maximum.


Here is a video on the unit

https://www.youtube.com/watch?v=JtAUrS4zNSA

It does have some downsides, the biggest one being it is limited to a max of 25 amps from the alternator anytime it is getting solar input, meaning in the dark you may get 50 amps alternator only, but at sunrise that may drop to 25 amps alternator, and 1 amp solar to get 26 amps total, instead of 49 amps alternator and 1 amp solar to make 50 amps total. Hopefully this shortcoming will be fixed in the next generation product.

[RonAz]

Does it say what will happen if the battery internal management disconnects the house batteries before the chassis battery is connected. Will this lead to a voltage spike to the alternator that could damage is diodes?
Perhaps using a second solar controller would allow for the full 50 amp alternator output. It would also seem that the chassis battery should always be charging when the engine is running. Lights, controls, and the toad all use power when driving. At the 50 amp setting the chassis battery might not charge for many hours if you have a large lithium bank.

[Isaac-1]

It does not say, though I have been playing with mine using a variable bench power supply and a constant output 13.8V 40 amp DC power supply to simulate the alternator the last few days while I wait on some battery cable lugs to arrive.


It certainly appears that it can be used with no solar input and use a separate solar charge controller and get full 50 amps from the alternator, alternatively some people have added a manual switch / automatic relay to disconnect solar input when the engine is running (ignition switched input) in order to get full alternator input and no solar, I am working on something a bit smarter to only allow solar input in bright sunlight when engine is running using a couple of relays and a low voltage disconnect.


As to your concern about the BMS disconnecting and causing feedback to the alternator I really doubt this would happen as the two seem very isolated in the DC-DC charger electronics, on the bluetooth app one can see alternator input voltage and amperage as well as battery output voltage and amperage which are often very different, ie the battery output voltage may be at lower voltage and higher amps than the alternator input while charging.

[RonAz]

I think that the RV manufactures need to get on board with the change over to lithium batteries. Many people are attempting various work arounds to be able to use lithium batteries. The biggest concern seems to be with alternator charging. Rv park, solar, and generator charging of lithium seems to have moved forward. It seems that the choices at this moment are to disable factory systems, experiment with something like dc-dc chargers, not use the engine alternator for charging the house bank, or take your chances.
The marine world figured out how to charge very large battery banks from an alternator back in the 90's. One simple alternative would be to disable the internal regulation of the alternator, or buy a new one, and add an external smart regulator to protect the alternator. Balmar is one example. This should leave all of the factory install intact.

[Isaac-1]

It is not that simple, LiFePo4 battery banks, particularly larger ones really need a DC-DC charger if they are going to be charged from an alternator, the issue is their very low internal resistance, which will allow them to suck down as much charge as is available, potentially either killing even a high output alternator, or causing their BMS (battery management system) to repeatedly disconnect and reconnect the battery output terminal due to overcharging and exceeding the maximum input charge current of the battery.


With a lead acid battery this is not needed as their internal resistance makes charging somewhat self limiting, this is why you need at least 13.8V to charge a lead acid battery that is at 12.8V, with a LiFePo4 you only need less than 0.1VDC voltage difference to get near full input current.

[RonAz]

The Balmar external regulator allows you to set the maximum output current for the alternator. If you use their alternator, it will also monitor internal and external temperatures and reduce the output to keep it the alternator from overheating by controlling the field current. I installed a large frame 24 volt Balmar alternator like this on a power boat. Expensive though.
The manufactures of RV's could start installing a DC-DC charger just like they have begun to install solar and solar regulators. For Tiffin's, you just have to get Tiffin, Spyder Controls, Battle Born, and one of the DC-DC charger manufactures to get together and figure this out. You can use the BIM-225 to partially solve the problem, but a DC-DC charger would be better in my opinion for my 2 cents worth.
With large Gel or AGM banks the alternator still needs to be controlled to keep it in it's happy zone of 50-60% of max output when run for long periods of time. I had a 240 amp alternator set at 80 amps and it almost got too hot to touch. This was on a four cylinder Yammar on which the crank pulley was too small to spin the alternator at its optimum speed.
I plan to go the DC-DC route, but I want to make it as automatic and safe as possible.

[Dbpublic]

I have had four battle born batteries installed. I made sure the inverter/charger (magnum) and the solar controller were set to lithium, they replaced the existing BIM with the one BB recommended (no DC to DC charger) plus a victron shunt to monitor the batteries. This time I paid for the installation at Redlands RV rather than doing it myself as I had on the old rig. It has been working flawlessly for a month and plenty of boondocking.

Looking forward to adding more solar and changing over to victron inverter/charger someday.

2021 Red 33AA