I have a Battleborn lithium house/AGM chassis battery system in a Sprinter-based mobile home. Battleborn has a battery isolator module that I'm having some issues with and am looking for alternatives. Can the Cyrix-Li-ct 12/24V-230A be used between these two banks without needing any other Victron components like the VEBus-BMS? Does anyone have any experience with such a setup and have any comments about alternator charging, isolation, or the programming strategy? Thanks.
the Cyrix-Li-ct 12/24V-230A can be used for that, there is no programing etc needed as its all preset in the units, but read the spec sheets to make sure it suits
@Paul B. I am trying to sort thru the specs. I can't tell if there is a bank joining function as the Battleborn isolation manager has for when engine is off and no charging sources are active. The banks are supposed to be joined if chassis battery goes below 12.5. Doesn't look like the Li-ct has this. This was supposed to act as a trickle charging failsafe for the chassis battery. Also, I'm having trouble interpreting the connect/disconnect specs listed on the product pdf. I presume the connect voltage spec scenarios refer to circumstances under which the Li-ct "opens" to allow alternator charging current to go to house bank when driving. And the disconnect voltage spec shows voltage that would disconnect the house and chassis banks for low chassis bank voltage? Not sure. Batteleborn batteries have a fairly similar charging profile as Victron's and a battery management system as part of their design. Wish there was a more detailed manual for a DIY person
@danglin I've been puzzling over the same setup. Assuming you're talking about the LI-BIM225 that Battleborn sells what issues have you run into with it?
The issue with just using the Cyrix-Li-ct as I understand it, is that on a long journey the alternator will charge the battery at the 14.x volts continually and lithium batteries are not meant to be floated at this level.
The system is designed to disconnect the starter battery when the voltage drops (when engine is off) but is designed for a BMS to do disconnects for the house battery to prevent overcharging.
I have also been trying to integrate a third party lithium battery. I have had a victron MPPT solar charger for a while that has provided my main charging. I have had the Cyrix-LI-ct to connect to the vehicle if needed but I have the charging on a switch and have been using for short periods. I have now added a BMV-712 and this now allows the cyrix to charge the battery and disconnects it when it hits 14.2v (not looking for alternator to take it to 100%). Early days with the BMV. . .
dazey77 What type of equipment do you use to connect the BMV712 with a switch to control/switch alternator charging on and off. Is this with a relay or switch controlled with the BMV? Do you wire some kind of disconnect controlled by the BMV just before the Cyrix Li-ct in the charging circuit?
The Cyrix-LI-CT has 4 terminals, starter battery, house battery, ground and the disconnect connection designed to go to the BMS. This has to be held high for the Cyrix to connect the batteries.
The BMV-712 has a relay on the back with normally open and normally closed contacts. I run a +ve battery feed to the relay and out of the normally closed port. This goes to the disconnect of the Cyrix. So normally it allows a connection, if the voltage rises over a set point then it goes low and the Cyrix disconnects.
@Mike Mitchell @dazey77 - Some may feel that the main issue I am having with Battleborn's LI-BIM225 is minor, but to me it isn't. The BIM225 joins the house and chassis banks for 1 hour many times per day - probably 18. It's supposed to serve as a failsafe/trickle charge function to prevent chassis battery depletion. The spec says that if chassis battery is < 12.5 and house voltage is > 13.5, the banks will be joined for one hour, then disconnect for 2 minutes and recheck voltages. If the voltages remain within the scenario's parameters, the joining response is repeated, etc. This occurs with the engine off and no charging sources active. If the LiBIM225 performed per this spec, it would be ok, but the batteries are joined with house voltage as low as 13.3 and chassis voltage of 12.6/12/7, basically a charged voltage. These voltages are measured at the posts on the BIM itself. The joining occurs with a loud "badurp" sound and is problematic for camping, since the battery isolator sits under the passenger seat, 3-4 feet from the Murphy bed. The Li BIM225 was designed by a company that mostly supplies equipment for large RV rental companies, where battery loss is an issue. The other thing is the duty cycle charging function while underway with alternator charging. From BB's website:
"Under normal charging conditions, the BIM will connect for 15 minutes every 35 minutes. That means that the BIM will connect for 15 minutes, disconnect for 20 minutes, and repeat this cycle until the coach battery is charged.
If the coach battery resting voltage exceeds 13.4V than the BIM will disconnect." I'm finding that the BIM lets current through at significant amperages for a few minutes before shutting off charging even though resting house bank voltage is over 13.4 after 2-3 charging cycles when driving. This is less of an issue overall. The BB's BMS shuts off charging to prevent overcharging. The alternator charging voltage is ≤ 14.1. BB and I think I may have a defective sample and I will be testing a replacement Li BIM225. I never see more than 50 amps being sent to the house bank, so alternator strain shouldn't be an issue for a 225 amp HD unit. I could not tell from the specs whether the Cyrix-Li-ct had any type of alternator duty cycle function by itself, but didn't think so.
