diy solar

diy solar

can’t find a inline 150amp battery breaker for 48v 16s

Those at alibaba are crap, skip them. Even with 100A load they become very hot.

Also, I highly doubt if they are capable of disconnecting in case of a short, most likely the just burn/arch and continue to let current pass.

Any reason why you need a disconnect? I'd go with Class T fuses, and if you really need to be able to disconnect either go for NH00 fuses (they can be removed easily), or if has to be removable also, go for a Class T fuse together with an Anderson 175A connector.
(Genuine Anderson ones, no China fakes!)

Note: There is a huge difference between beeing able to disconnect a low current, or capable of switching high currents! An Anderson 175A connector can be used fine for disconnecting when not in use, but I won't use it to disconnect a battery under huge load!

Also, pay attention to proper crimping and torque settings. Even the best breakers can overheat or fail when not properly connected.
 
i dont see a in-line type fuse/breaker that will work from midnight
 
DJSmiley said:
Those at alibaba are crap, skip them. Even with 100A load they become very hot.

Also, I highly doubt if they are capable of disconnecting in case of a short, most likely the just burn/arch and continue to let current pass.

Any reason why you need a disconnect? I'd go with Class T fuses, and if you really need to be able to disconnect either go for NH00 fuses (they can be removed easily), or if has to be removable also, go for a Class T fuse together with an Anderson 175A connector.

Note: There is a huge difference between beeing able to disconnect a low current, or capable of switching high currents! An Anderson 175A connector can be used fine for disconnecting when not in use, but I won't use it to disconnect a battery under huge load!

Also, pay attention to proper crimping and torque settings. Even the best breakers can overheat or fail when not properly connected.
Click to expand...

i just wanted a safety breaker in the batteries, just incase
 
There's a youtube video from "Lithium Solar" who makes a very valid argument for using Class T fuses as the catastrophe fuse with LiFePO4 batteries. I assume you are using that type of battery with your 16s BMS. if you get to reading the literature use a class t fuse next to the battery.

I bought class T fuses as the primary safety and use the non-polarized breakers as a secondary to disconnect.
You usually have to get a 250-volt dc breaker or 300-volt DC breaker or 600-volt Dc breaker to get a breaker DC rated that will be rated adequately for 150 amps.

do not trust the automotive junk.

I suggest you study up for your safety if using the high voltage DC. :unsure:
Ask lots of questions, and read a lot.

many variables -- fuse should be 1.25 times the wire carrying capacity is one rule of thumb. so you may want 150amps x1.25=187.5 amp fuse (round up to 200 amp fuse. make sure the wire is large enough. can never go wrong with a larger gauge wire than you actually need. the fuse protects the wire and also whatever (appliance) is downstream from it.
 
I started originally with LittleFuse Class-T fuses but after I had two come apart I surrendered and went over to using Bussman MRBF Fuses and haven't looked back since. Bussman & Cooper are now owned by Eaton so product quality & dependability remain very high. These are used by BlueSea as well as several High End OEM's & VAR's and can be found quite often in the Marine World.

REF http://www.cooperindustries.com/con...otection/fuses/marine_rated_batteryfuses.html

The pricing is pretty good too and readily available.
www.ebay.com

Bay Marine – Marine Rated Battery Fuse and MRBF Single Fuse Holder Kit – 30-300A | eBay

Choice of Fuse Sizes Available: 30A, 40A, 50A, 60A, 75A, 80A, 90A, 100A, 125A, 150A, 175A, 200A, 225A, 250A, 300A. Fuse Size List Ignition Protected – Safe for installation aboard gasoline powered boats.
www.ebay.com
 
In the case that the wire size is increased due to voltage drop go ahead and use a fuse or breaker that matches the load. If I have a 15 amp circuit and need to use #6 wire there is nothing to be gained by using a 50 amp fuse or breaker and it will prevent a disconnect in the case that the device which is being powered is overloaded such as when a motor fails to start.
 
Keith Moreau said:
@cinergi I'm wondering why you're switching from class T to the panel mount breaker? Convenience? Thanks much.
Click to expand...

initially because I kept blowing the fuses with inrush current and that alone would pay for a new breaker. And now it’s convenient because I can turn off the battery including the BMS.
 
For those wanting more information about the breaker that cinergi is switching to, here is the web page for that product:

Product - MidNite Solar

MidNite Solar Product Page.
www.midnitesolar.com

Relevant details from that page:
MidNite's breakers are rated to break the full rated load at the rated voltage repeatedly, with NO DAMAGE. Always use a properly sized breaker for disconnecting.

All MidNite circuit breakers can be used at 100% rated current when mounted in a MidNite enclosure.

Breaker Torque Value: 15 Ft-Lbs (20.4NM)
  • NON POLARIZED
  • Environmental Rating - Type 1 (Indoor)
  • Width 1.5 inches (39mm)
  • 125VDC Panel Mount Breaker - 3/8" studs
  • AIC 50,000 at 125VDC
  • Breaker Torque Value: 15 Ft-Lbs (20.4NM)
  • Includes two 10-32 x 3/8 Pan Head Phillips mounting screws
  • Warranty - 5 yrs.
  • Listed for US & Canada
Click to expand...

My take from the specs: This looks like a good substitute for the Class T fuse. Is it also a way to replace both the Class T fuse and the battery disconnect switch? Seems like it. It would take up a heck of a lot less space in the component compartment, that's for sure. Since it uses studs, there is no question about the largest size wire it can handle. A mounting bracket appears to be necessary so that the cable studs aren't touching anything.
 
@cinergi You may have mentioned this but rather than me going through all the posts what AWG wire did you wind up wiring to the output of the 250A Midnight solar breakers? I'm building 2 16s batteries very similar to yours. For now I'm going to try to connect them directly to the battery posts with a thick busbar with some additional support so there isn't strain on the battery post. By the way I ordered the breakers, I got the ones with 'remote relay' although there is some Midnight solar proprietary signal required (confirmed through Todd of Midnight Solar, it is a pulsed 24 up to 36v signal to trip it. The tripping coil can't take continuous 24-36 volts. I don't know if I'll ever need the remote but it's not too much more expensive than the standard ones so couldn't hurt.
 
HRTKD said:
For those wanting more information about the breaker that cinergi is switching to, here is the web page for that product:

Product - MidNite Solar

MidNite Solar Product Page.
www.midnitesolar.com

Relevant details from that page:


My take from the specs: This looks like a good substitute for the Class T fuse. Is it also a way to replace both the Class T fuse and the battery disconnect switch? Seems like it. It would take up a heck of a lot less space in the component compartment, that's for sure. Since it uses studs, there is no question about the largest size wire it can handle. A mounting bracket appears to be necessary so that the cable studs aren't touching anything.
Click to expand...
I thought about going with a breaker instead of a class T fuse and on/off switch but mounting the breaker looks awkward to me.
And I don't have the inverter inrush issue. It is easy for me to find someplace to mount a fuse and a switch.
 
It's a HUGE breaker. But the convenience of having a breaker is not for the initial onrush but to protect each of the 48V batteries running in parallel from a short inside a battery, same as a fuse, plus I was looking at the T fuses and though they are smaller they still seem to need to be supported by a holder and they don't have the convenience and safety factor of being able to shut each battery off while connecting, maintenance, etc. Though breakers are $$$, the genuine fuses and holders are not cheap. But we'll see, maybe after getting these huge breakers I'll regret my decision.
 
Keith Moreau said:
@cinergi You may have mentioned this but rather than me going through all the posts what AWG wire did you wind up wiring to the output of the 250A Midnight solar breakers? I'm building 2 16s batteries very similar to yours. For now I'm going to try to connect them directly to the battery posts with a thick busbar with some additional support so there isn't strain on the battery post. By the way I ordered the breakers, I got the ones with 'remote relay' although there is some Midnight solar proprietary signal required (confirmed through Todd of Midnight Solar, it is a pulsed 24 up to 36v signal to trip it. The tripping coil can't take continuous 24-36 volts. I don't know if I'll ever need the remote but it's not too much more expensive than the standard ones so couldn't hurt.
Click to expand...

I had two 1 gauge wires from the cells to the line side at one point (and 3/0 from the load side to my main 48v bus). I'm now running 1/8" x 3/4" bus bars to/from it.
 
Keith Moreau said:
It's a HUGE breaker. But the convenience of having a breaker is not for the initial onrush but to protect each of the 48V batteries running in parallel from a short inside a battery, same as a fuse, plus I was looking at the T fuses and though they are smaller they still seem to need to be supported by a holder and they don't have the convenience and safety factor of being able to shut each battery off while connecting, maintenance, etc. Though breakers are $$$, the genuine fuses and holders are not cheap. But we'll see, maybe after getting these huge breakers I'll regret my decision.
Click to expand...

Here's my setup:

IMG_9259.JPG
 
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