battery tender fuse

[JamesW]

Putting a battery tender harness on my 2013 and notice it comes with a 7.5 amp fuse. I plan on plugging this in to a power outlet so I may use things like an electric air pump (slime). Question is, is it a good idea to upgrade the fuse to say a 10 or 15 amp?

 

[Queensland Ken]

Hi,

My slime pump draws upwards of 16 amps under load, a 20 amp fuse would be fine. I Measured the value.

Should blow if the wires loose their electrons.

 

[mcatrophy]

Putting a battery tender harness on my 2013 and notice it comes with a 7.5 amp fuse. I plan on plugging this in to a power outlet so I may use things like an electric air pump (slime). Question is, is it a good idea to upgrade the fuse to say a 10 or 15 amp?

As a general rule it would be unwise as the fuse is there to protect the wiring. If you are simply going to use something like a pump, that would be no problem, for the few minutes the pump was running there wouldn't be excessive heating. But if it was a long-term load, say lights or heated clothing, it would not be a good idea.

 

[HotRodZilla]

I'm not sure what's in my pigtail, but for some reason I think I was surprised to see a 7.5 amp fuse on there. On the rare occasion I have run my Slime pump there it has been fine. I normally use a marine plug with a 10amp breaker in it. It has never blown.

 

[DennisJ]

I leave the fuse in the Deltran Battery Tender Jr. at the factory 7.5 rated fuse. My Eastern Beaver PC-8 has the 30 amp relay so that has a 30 amp fuse in it. The Battery Tender is connected directly to the battery with the lead coming out between the tank and the cowling. Discreet and so far trouble proof.

 

[JamesW]

Seems like accessory folks do not bother posting wiring gages.

 

[rbentnail]

Seems like accessory folks do not bother posting wiring gages.

Indeed. The fuse size is determined by the wire size. Without that info one can only guess.

 

[AKjitsu]

OK. Guess I get to be the red neck. I use a 15 amp fuse in mine. Use it for electric pump, electric gear, you name it. After many years and many thousands of miles, it has yet to catch on fire, explode, give me hemorrhoids, cause the San Andreas fault to let go, or raise the national debt. Or maybe I just haven't noticed.......

 

[flstffxe]

Seems like accessory folks do not bother posting wiring gages.

Indeed. The fuse size is determined by the wire size. Without that info one can only guess.

All of the Battery tender pigtails I have 18ga printed on the wire insulation.

Going of my old Handbook of Electronic Tables and Formulas. This puts the max amp load at 16amps, though this is only based off a "rule of thumb" as circuit design, insulation, temp and air flow all play a part in what is safe.

 

[ionbeam]

It will be the terminals where the heat hits first. How the terminals are attached (crimped/soldered/welded) will be more significant than the actual wire gauge. Terminals are where quality matters, both in materials and workmanship. The next time you jump start a car with a really dead battery, right after the dead car starts, feel the mid point of the cable then feel right where the wire attaches to the terminal clamp. Be careful and don't burn yourself. This will be true of the ring lugs on the battery tender pigtail and the SAE connector pins.

If the high power draw is for a short duration you can exceed 100% wire ampacity without harm, but if your 15 amp tire pump runs for >5 minutes you risk melting the wire insulation near the terminals. If you are putting a 20 or 30 amp fuse on an accessory wire, just remember that the main charging system fuse is 50 amps and you could be allowing 60% of the total system current to flow before the accessory fuse pops.

 

[RaYzerman19]

+1 Alan. The 7.5 amp fuse is likely designed to protect the Battery Tender..... very tempting to upsize the fuse and use it for accessories, however I'd try to keep it to 10A for constant usage. Maybe the air pump won't blow it, just try it. That said, I'm a cheater on this one (15A but not for continuous use such as heated gear).

 

[cyclemed]

Here is my thought. The batter tender harness has narrow guage wire inside sobit will not hold up to moderate current draw (don't ask me why I know this ). What I do if I want to share the cable duty is order a pig tail from Powerlet or Gerbing as theirs are made to withstand 20Amps or so. Then using it for the battery tender is fine too.

Short version is battery tender won't hold up to large current draw but powerlet or gerbing made for this draw will be fine for miniscule draw of the tender.

Hope this helps.

 

[art miller]

I'm reading this topic with great interest. I want to install an axillary outlet on my 2014. On my 07 I placed a marine outlet on the left side (square panel where grip warmer dial goes). I used 20 amp rated wire and fuse. On the 14ES that area is completely taken up by various electrics. On the right side there is a very limited area under the black horizontal panel just to the left of the hex head fastener. My concern is if I cut a 1" dia hole that close to the fastener and the left edge of the panel, it may weaken the panel and risk breaking when removing and installing over time. Has anyone installed the marine (cigar lighter) outlet on the 14ES? Is there space behind the black vertical panel in front of the horizontal panel over the battery? Any suggestions appreciated.