Lithium Iron Phosphate (LiFePO4) Batteries

[davidbrady]

(12-21-2014 00:25)Wanderer Wrote:  The 450 has 3 equalizers. If you look forward of the battery tray there is a third equalizer. It is jammed under the buss bars forward of the batteries.

Really hard to find

Trying to figure out how to split the system for the Liths and 2 AGMs for starting.

Hi Dan, tell us more about your requirements.

My H3 is blessed with two Vanner Equalizers. Most Prevost converters are very careful not to intrude or cut into any factory Prevost wiring harnesses; the converter house stands on its own in most cases. The Prevost chassis uses one equalizer to split 12V out of its 24V chassis battery bank. The converter followed suit with the house batteries; i.e., 24V battery bank to supply the inverters and the slide motors and a Vanner Equalizer (center tapped into the house battery bank) to supply the 12VDC loads including the generator start. My focus is on the house; I'd leave the 24V chassis bank and equalizer untouched.

Here's a schematic of my house system with split 24/12VDC battery bank and twin SW-4024 inverters:



My largest 12V draw is the generator start motor. A simple solution here is to break out this draw with a dedicated 12V start battery for the genny. (Dan, for the M450 as Greg and Forest suggest, dedicating a battery bank and a charger to the C13 start motor may be the solution for that equalizer).

That leaves the remaining 12V house loads which include just about everything DC powered in the house: mostly lights, electronics, a handful of motors (shades, sofas, pocket doors, dump valves), Aquahot, Glendinning, tank levels, etc.

I'm thinking a good way to handle these loads is with a DC-to-DC converter, 24VDC in and 12VDC out. My 12VDC distribution panel is protected with a 100A circuit breaker so I need a 100A DC to DC converter, 24VDC in 12VDC out. I haven't yet found a high quality off-the-shelf converter with anything close to these specs; if you find something please let me know. I may have to build it.

(12-21-2014 10:14)folivier Wrote:  On my Newell which has 2 8D start batteries (12volt system) I installed a Trik-L-Start to keep them charged. It took power from the LiFePO4's. Could you add 1 to each battery in order to keep yours charged?

Hi Forest,

Can you share some pics of your installation? Who's batteries did you go with? What kind of DOD do you impose on them? Are you running a per cell voltage monitor that controls a Low Voltage Cutoff contactor? Have you done any battery cell balancing? Thanks!