Attaching a fuse to a new set of batteries?

KRumm wrote:
One of the downsides is that blown fuse needs to be replaced....

What about installing a circuit breaker instead?...

Breaker is not a replacement for battery fuse. Fuse is mounted as close to the battery as possible (ideally - on the battery). Breaker is mounted where it's easily accessible. The correct way is to run Pos wire from the battery fuse to Pos bus, and from there to various breakers.

mlts - 300A is an overkill unless you have a big inverter. With 2*12V you don't want to run more than 100A, so - even with inverter you don't need more than 200A fuse.

Thanks for the info. The purpose of the fuse is for use as catastrophic short protection, and one of the reasons I went with the current setup is because it is easy to install -- just bolt onto the positive battery terminal, call it done.

Unfortunately, 2015 was a tad rough, so I didn't get out as often as I wanted to ensure that batteries were maintained. Oh well. Two decent 12 volt jars are going to allow me to run the 7-10 amp propane furnace fan without worry that the battery lasts the night. I had plans to trade in the TT for a while now, but with all the craziness encountered last year, I will wind up keeping it this year until life gets back to some calmness.

300a seems big for 1/0 wire. I would go 250 max ANL or 200 max class T.
Branch circuits will have smaller fuse rating depending on wire.

I would use an auto reset circuit breaker or a manual one.

I presently am running 255AH battery bank protected by BLUE SEA 4-position high current marine grade DC switches and fuse assemblies.

This is my battery scheme layout for four 85AH batteries connected in parallel. I am only running three of these batteries at the present time...



Hopefully this season i get to replace my 2009 installed batteries and if I end up getting four 6VDC golf cart batteries due to their lower cost I will hook them up like this layout...



My battery cables between the on-line converter and the batteries will be protected from dead short to ground by a 130AMP ANL FUSE block assy from BLUE SEA. The direct battery connection line from the battery swicth to the 1500WATT POWER CONVERTER will be the same type BLUE SEAS Fuse assy but will be using a 175AMP ANL type fuse. This is physically mounted behind an outside cross tongue frame panel just inches away from the master four position Blue Sea battery switch. Parts numbers shown in the diagrams..

My success for long term battery life is to never ever let them drop below 12.0VDC in operation and get re-charged back up to at least their 90% charge state with in a 12-14 day charge cycle period doing the three hour charge cycle everyday. After that I do a full charge cycle which takes around 12-13 hours to get to a full charge state.

When camping I just monitor the battery DC VOLTS with a built-in DC VOLTMETR panel and when they get down to the 12.0VDC level I quit using them until I start the recharge cycle to get them back up to their 90% charge state. Just reading the Dc VOLTMETER is of course not absolute for determining the battery charge status but is close enough for me to react to. Everything is planned to make this 50% battery bank charge state event happen at 8AM each morning when I can run my 2KW Honda Generator at most of the camp sites we visit that has generator run time restrictions in place.

This is what we do when camping off the power grid haha... Obvisouly others do it differently. Some just use flashlights and candles and jump up and down their single battery makes it through the night. We do just about every we do at a regular electric site camping trip except running the air conditioner or high wattage microwave. Also when it is cold weather it gets a bit exciting when having to run the high wattage propane furnace blower fan all night long.

Roy Ken

1. The distribution panel is only rated for a 30 amp feed from the battery.
2. Fuses are a known failure point use a breaker.
3. Another higher amp fuse or breaker is used to feed an inverter per the inverter requirements.

Fuses are used when precise limits are not to be exceeded. They are perfect for use with high draw stuff like an inverter. 150-amps per battery sustained is a lot. Do you ever need say 150-amps total both batteries from your battery bank? This advice is merely ideas to take into consideration.

With fuses, remove the element then smear silicone grease into all the nooks and crannies. Use a Q-tip. Then smear silicone grease over 100% of the fuse itself then assemble. Might as well make stuff corrosion and oxidation proof. If you connect a LOUD alarm across both terminals of a fuse it will screm its fool head off announcing the Four Horsemen Of The Apocolypse are there.

One of the downsides is that blown fuse needs to be replaced....

What about installing a circuit breaker instead?... You can also have it as a battery cutoff

XSCORPION (CB300L) 300 Amp Circuit Breaker with Manual Reset and LED Status Indicator

A 200 amp fuse should be plenty, and will trip a little before a 300 amp will. Do you have golf cart batteries now? You will not be happy with a 1 year life of a 12 volt battery if you had been getting two years from the golf cart battery.

You need to keep them charged all the time. I did this with my solar system, and the first set lasted 13 years with proper care and watering every 3-4 months. The best I had ever gotten out of 12 volt batteries was about 2 years.

Good luck,

Fred.