Yes, your T100’s alternator will be happier if you limit the current draw with a DC-DC. The DC-DC also provides “intelligent” charging, vs just dumping current into the battery.
Thank you Vic!
Posted 22 March 2023 - 02:07 AM
Yes, your T100’s alternator will be happier if you limit the current draw with a DC-DC. The DC-DC also provides “intelligent” charging, vs just dumping current into the battery.
Thank you Vic!
Posted 22 March 2023 - 02:15 AM
Thank you Vic!
Bruce, allow me add a few more details:
My question:
Does the ACR provide the necessary current limit for a “dumb” alternator when charging a LiFePO4 battery?
-- No. The ACR connects the truck to the camper when it detects that charging current is available from either side. And disconnects the two systems when it detects that the one may drain the other.
Can I (Should I) leave the AOPEC and add a Victron DC-DC charger to limit the current?
-- No. Most folks replace the ACR with the DC-DC. I say most, because I have both. I'll add a comment to my power thread to explain.
My limited understanding is the AOPEC will allow 140 A (and the Blue Sea allows 500 A) >> 30 A
-- Allow? Not really. That is their rating. Beyond that smoke/sparks start flying.
Or will the DC-DC prevent the ACR from functioning?
-- Correct. They are not designed to work together.
Posted 22 March 2023 - 02:39 AM
The isolator and a DC-DC converter are; very, very roughly; parallel type components.
I am unsure of what you want the system to do. I'd say let's start with what you've listed above and work towards the goal of what you want the system to do.
Hi ntsqd
Thank you very much for your reply.
My goal is just to replace my AGM with a LiFePO4 and make sure I don’t fry my alternator.
I was concerned I might be missing something with
“If you want to charge the truck from the camper, then you can’t use the DC-DC charger wired like this.
Thanks again
-Bruce
Edited by Ruffinit, 22 March 2023 - 02:44 AM.
Posted 22 March 2023 - 02:52 AM
Can I (Should I) leave the AOPEC and add a Victron DC-DC charger to limit the current?
-- No. Most folks replace the ACR with the DC-DC. I say most, because I have both. I'll add a comment to my power thread to explain.
Yes, I thought that might be the case from your summary. You have both?
Edited by Ruffinit, 22 March 2023 - 02:52 AM.
Posted 22 March 2023 - 02:56 AM
My limited understanding is the AOPEC will allow 140 A (and the Blue Sea allows 500 A) >> 30 A
-- Allow? Not really. That is their rating. Beyond that smoke/sparks start flying.
I didn’t mean allow in a good way! Just not prohibit!
Posted 31 May 2023 - 09:20 PM
2022 Ford F-150 HDPP with 2022 ATC Puma Shell
Posted 01 June 2023 - 12:29 AM
I'm not Vic, but I'll take a stab at this.
The main purpose of the larger gauge wire/cable between the truck and the camper is to reduce the voltage drop as much as is reasonable. A DC-DC converter largely, but not totally, negates this need. I feel that 4 ga. is excessive for 30A. I used 6 ga. without a converter for an estimated 80A peak and I'm well under 3% at normal charging amps. With a 30A converter I would expect that 8 ga. would work well and 6 ga. would be appropriate overkill.
Consider using a breaker at the truck batteries too. One that allows a manual disconnect like 285 Series from Eaton but sold by most everyone. While the Anderson connector will make/break under load I never do that and the breaker under the hood is the easiest for me to get to in order to open the circuit. It is also nice to be able to turn off the circuit between the breaker and the Anderson Connector to work on that section of cable.
I would operate under the assumption that ATC sized the ground wires appropriately until proven otherwise. That said, I'm not a fan of multiple ground or hot wires connected to the battery. When I rewired our first camper I considered the fuse panel & ground buss to be the consumer of the power supplied to it and sized the main hot and ground wires appropriately for their length and the max possible draw that the fuses would allow - offset with a small dose of reality i.e. not everything is likely to be all running at the same time. It was a short bed camper with the panel at one end and the battery at the other, but as I recall 10 ga. was the largest wire size that I used inside the camper.
I would leave the ATC installed ground cable between the ground buss and the frame in place. Unless you plan to turn the frame into the only ground buss I would only make one connection to it. Sometimes having a ground loop, that is a circular path within the ground system, doesn't matter, other times it will drive you knucking futz. Just what comprises a "ground loop" can get contentious. I define them as multiple paths to ground from any consumer of power. Better to just avoid them.
Posted 01 June 2023 - 02:24 AM
I left the entire FWC 10ga wiring in place when I ran my 6ga wires. Has caused 0 issues for me.
Craig K6JGV_________________________ 2004 2500 CTD 4X4 FWC HAWK 1960 CJ5
Posted 01 June 2023 - 09:51 PM
+1 to Thom's suggestion of a breaker at each end of the run between truck and camper. Handy, as well as safer to fuse that fat wire on both ends.
Thanks for reading my posts!
I'm not sure which brand mppt you are using, but Victron gear can only accept up to 6AWG, so I run that from my bus bars to the Victron gear.
6AWG minimum seems to work best for the camper to DCDC run, at least in my experience and KP has mentioned the same.
Ground loops suck, so keep grounding points to a minimum. Worst case scenario is if your primary ground is disconnected somehow and everything has to go to ground through some small left over ground wire hidden in the walls. That wire might be undersized and melt! So, knowing where those grounds are is important.
Think of your camper as an independent unit from the truck, meaning GROUND in the camper is just that... camper ground. When plugged into the anderson connector, there is an intentional (and thick) wire running to the truck so that you now share a ground. It is not really ground (since you are running on rubber tires!).
Thanks again for the kind words!
Posted 03 June 2023 - 04:58 PM
2022 Ford F-150 HDPP with 2022 ATC Puma Shell
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