I have 2 100 amp hour batteries in parallel. I put Blue Sea 250 amp fuses on each positive post. Now I am installing a 2000 watt inverter which also calls for a 250 amp fuse. That's 3 of the same size all together. If I had an inverter problem could I possibly take out all of them at once? Any ideas of what I should do. Thanks..
Fusing problem.
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John Frum
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Unlikely.
Assuming all the fuses are the same and wires are the same guage and given a sane topology, If the inverter shorts, the batteries and respective fuses will each see aproximately half the load.
The inverter fuse will see the full load and should blow first.
Assuming all the fuses are the same and wires are the same guage and given a sane topology, If the inverter shorts, the batteries and respective fuses will each see aproximately half the load.
The inverter fuse will see the full load and should blow first.
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Alphacarina
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Your inverter is 'looking back' at a pair of 250 amp fuses in parallel. Since the inverter calls for a 250 amp fuse, you either need a third 250, or, better yet, replace the existing fuses with 125 amp fuses. What made you select 250 amp fuses for each battery? Do you have cabling on the individual batteries rated to carry 250 amps? Remember, fuses are to protect the wiring, so they blow before the wire is damaged or it's insulation catches fire
Don
Don
Thanks for your reply. It seems all the wiring diagrams I see use 250 amp fuses for 2 parallel 100 amp batteries. I thought it would be even a little safer to protect the other battery in case a wrench was dropped on the un-fused battery. If I am running a 200 amp load wouldn't that blow one of them 125 amp fuses? As you can tell I am somewhat a newbie at this. Maybe I am being over cautious. I am using 2/0 cable.
Thank you for your reply.
If the connections are good each battery will share half the load or 100 amps each and have no issues with 125 amp fuses. Although that is edging fairly close to the fuse rating and possibly the battery rating. Might do better with 3 or 4 batteries if you will be running 200 amps for any extended period or on a regular basis even if brief. Not sure what is pulling 200 amps.... full size microwave is closer to 150a at 12v feed. 2/0 cable is not oversized.
This will never be hard used watts wise. Maybe 4 or 5 minutes of small microwave. I was going to put 250 amp fuse on each battery to protect my friend from accidentally dropping wrench or something on the battery without a fuse. I see it in diagrams all the time people using 250 amp fuses. But in those cases it protects both batteries with one 250 amp fuse. So if I use 2 fuses to protect both batteries individually for safety sake I need to decrease my fuses size, is that correct?. Thank you.
