Retro Posted July 16, 2020 Share Posted July 16, 2020 So I bought a 1Kva Axpert 12v inverter to use with my 100ah gel battery, still waiting on the inverter to arrive. I've done some searching and noticed that the inverter doesn't come with any battery cables. I was thinking of possibly using old jumper cables that I had laying around and getting the correct fittings for the end of the cables? Or does anyone recommend a specific type? Second, I've had 1 or 2 people telling me to use some sort of circuit breaker with my build for extra protection - I want to make a build like this from geewiz , I need help as i have no clue what to get. Quote Link to comment Share on other sites More sharing options...
Coulomb Posted July 17, 2020 Share Posted July 17, 2020 18 hours ago, Retro said: I was thinking of possibly using old jumper cables that I had laying around I find that jumper cables are more plastic than copper these days. Yes, they can take 200 A to start a car, but you need nearly 100 A continuous to get 1075 W at 11 V into the inverter. It usually only takes a few seconds to start a car. So you need at least 25 mm² of copper (so that's around 5.6 mm diameter of actual copper), preferably 32 mm² (6.4 mm diameter), since voltage drop wastes a lot of power at just 12 V nominal input. A 100 A DC rated circuit breaker is big and expensive. Consider a proper DC rated fuse, and fuse holder that is designed to disconnect. These will be big and not cheap, but not as bad as a high current DC breaker. Some form of pre-charge would also be good. Quote Link to comment Share on other sites More sharing options...
Retro Posted July 25, 2020 Author Share Posted July 25, 2020 Ive got everything setup, and it seems the fan comes on at 100% every 20 min or so for about 10 min (plugged into mains and battery is 100%) - is this normal? and is there perhaps a way to turn the speed down? Quote Link to comment Share on other sites More sharing options...
Retro Posted July 25, 2020 Author Share Posted July 25, 2020 it feels like its basically always on now. I might have to move it if its meant to be like this because the fan is really annoying Quote Link to comment Share on other sites More sharing options...
Retro Posted July 26, 2020 Author Share Posted July 26, 2020 @Coulomb Do these setting look correct? i have 100 ah gel battery Quote Link to comment Share on other sites More sharing options...
Coulomb Posted July 27, 2020 Share Posted July 27, 2020 11 hours ago, Retro said: @Coulomb Do these setting look correct? I can't see that image. You're not linking to the actual image; the above seems to be a folder. Quote Link to comment Share on other sites More sharing options...
Retro Posted July 27, 2020 Author Share Posted July 27, 2020 @Coulomb try this link - https://imgur.com/a/FJIj4wQ Quote Link to comment Share on other sites More sharing options...
Coulomb Posted July 27, 2020 Share Posted July 27, 2020 20 hours ago, Retro said: Do these setting look correct? They look OK. However, Axpert's "AGM" settings are a bit tame, especially for actual AGM batteries. Check your battery datasheet to see if you might be able to charge at 20 A, or raise the absorb voltage setting (setting 26); to do this you'll have to change battery type (setting 05) to USE. But be careful in summer; higher temperatures mean lower allowed absorb voltages. I'm surprised you're able to set the battery cutoff voltage to 12.0 V with battery type = AGM. You should in any case set it as high as possible, to preserve battery life. Ideally, for load shedding, you'd want to put this at 12.2 - 12.4 V (depending on load), but likely 12.0 V is the maximum. Try to keep the load fairly low. At full power (1.0 kW), the battery will last less than an hour to dead flat, and you should not use more than 50% of even that. Quote Link to comment Share on other sites More sharing options...
Retro Posted July 27, 2020 Author Share Posted July 27, 2020 Just now, Coulomb said: They look OK. However, Axpert's "AGM" settings are a bit tame, especially for actual AGM batteries. Check your battery datasheet to see if you might be able to charge at 20 A, or raise the absorb voltage setting (setting 26); to do this you'll have to change battery type (setting 05) to USE. But be careful in summer; higher temperatures mean lower allowed absorb voltages. I'm surprised you're able to set the battery cutoff voltage to 12.0 V with battery type = AGM. You should in any case set it as high as possible, to preserve battery life. Ideally, for load shedding, you'd want to put this at 12.2 - 12.4 V (depending on load), but likely 12.0 V is the maximum. Try to keep the load fairly low. At full power (1.0 kW), the battery will last less than an hour to dead flat, and you should not use more than 50% of even that. Im only planning on using it for Wifi and perhaps a laptop depending on how long loadshedding is. I also had it at 20A and someone mentioned that lowering to 10A would be better for the battery long term. Quote Link to comment Share on other sites More sharing options...
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