Renogy DC-DC Test Results-UPDATE 4 (Better!)
Updates 23 June--new test with Renogy input exposed for voltage readings Update 25 June more readings Update 4 - 27 June-- fewer amps with fat wire were noted this time! ----- I have the 20 ampe...
Forum Discussion
otrfun wrote:
Took these current/voltage readings right after we installed a 40a Renogy dc to dc charger in our truck camper (truck has a 220a alternator). Used ~23 ft. of 2 gauge cable to fabricate the positive run from the TV battery to the Renogy located in our truck camper (via several 175a Anderson-type connectors). Used approx. 5 ft of 2 gauge for the negative run (truck frame just below the truck bed to the Renogy in the truck camper). Remaining negative run (from the truck's battery to the front of the truck bed) was via the truck's frame and OEM negative cabling. All readings are approx.
1. 14.1v 43.5a measured where the 2 gauge cable terminated at the TV battery terminal (alternator online)
2. 13.8v 42.2a at the Renogy's input terminal
3. 40a at Renogy output terminal (current remained steady at approx. 40a while charging LifePo4 battery from 15% SOC to ~97% SOC)
4. 39.8a at LifePo4 battery terminal (~10 ft run of 2/0 cable from the Renogy to the LifePo4 battery; voltage drop <.1v)
You can drop these current readings by 50% if you want to get a rough idea of how a 20a Renogy would have performed (installed on our TC and truck). This would be based on using one cable size larger than what Renogy recommends for the 20a Renogy for our install. Renogy recommended 4 gauge for our 40a Renogy install; we used 2 gauge.
thats what I wanted to see. do you think there would be any benifit of going larger than 2ga or do you think at that point its not worth the extra money?
Steve
