I was waiting to see what the new alternator charging solution would be from Victron but seems like the solution is more of a trickle current wise than what I'd like to see. I've got a big bank 32 cells of Calb 180ah @ 3.2v, wired in series/parallel to 24v nominal bank @ 720ah. I need a firehose not a dribble of current for charging [staying at or below .3C charging, which for this bank would be 54a*4 or 216a, regardless of input voltage]. Looking for some feedback on potentially the best way to proceed. All amps below are listed as 12v with 24v in ( ) next to it.
Goals:
1. Up convert alternator output from 12v to 24v.
2. Protect alternator from overheating.
3. Protect alternator from voltage spikes due to charging circuit being disconnected.
4. Limit charge current to no more than 50% of alternator maximum output.
5. Provide 3 stage charging profiles for Lifepo4.
6. Sync charging with smart solar mppt while driving.
7. Integrate into the Venus GX and provide visibility of current produced.
8. Isolation from starter batteries (dual on F550) to prevent draining/damage.
Environment:
1. F550 extra heavy duty dual alternators with outputs of 220a and 157a or 377a combined. 50% of this would be 188a (94a) These alternators are also temp compensated to my understanding. (see attached output graph below).
2. Uplink cable 2awg
3. 720ah 24v Lifepo4 bank in basement of truck camper.
Proposed solution:
1. (2) buck boost 12/24 converters 100a (50a) + 50a (25a), combined 150a (75a) installed in parallel within the cab of truck. Initally I will start with a single 100a (50a) buck boost and add the additional 50a (25a) later if everything seems stable charging wise.
2. Uplink cable connects to second Smart Solar 150/85 mppt.
3. Second Smart Solar 150/85 mppt connects to positive and negative bus bars within camper.
4. Second 150/85 mppt would connect to the Venus GX for management.
Ideas, thoughts, feedback?
Thanks!
