36 replies to this topic

[MarkBC]

...Where do you have your batteries if they have to vent?

 

The batteries are in the storage area under the couch -- at the front end of that box, next to the cubicle where the original single (AGM) battery was placed by FWC.

Venting is provided by the turnbuckle access slider, which is next to the batteries, propped open about an inch.  

 

Is this safe?

It's safe enough for me -- and I've run it this way for 6 years without a single explosion (at least, none that I recall).

The potential hazard is the small amount of hydrogen gas that evolves when the battery is being charged and water is split into hydrogen and oxygen.  But hydrogen diffuses -- dissipates -- very fast (almost 5 times the diffusion rate of propane).  And the LEL of hydrogen is 4 vol-%, which is higher (less flammable, by this measure) than most volatile substances (propane is 2 vol-%).

 

But I'm not suggesting to anyone else that they do what I do.

And if folks decide that my camper isn't safe to visit at the upcoming Rally, I won't be offended.

[Ethergore]

The batteries are in the storage area under the couch -- at the front end of that box, next to the cubicle where the original single (AGM) battery was placed by FWC.
Venting is provided by the turnbuckle access slider, which is next to the batteries, propped open about an inch.  
 
Is this safe?
It's safe enough for me -- and I've run it this way for 6 years without a single explosion (at least, none that I recall).
The potential hazard is the small amount of hydrogen gas that evolves when the battery is being charged and water is split into hydrogen and oxygen.  But hydrogen diffuses -- dissipates -- very fast (almost 5 times the diffusion rate of propane).  And the LEL of hydrogen is 4 vol-%, which is higher (less flammable, by this measure) than most volatile substances (propane is 2 vol-%).
 
But I'm not suggesting to anyone else that they do what I do.
And if folks decide that my camper isn't safe to visit at the upcoming Rally, I won't be offended.

That's hilarious. I actually thought about doing it that way but am worried about getting a bunch of dust in there. I even considered doing a filtered vent or something.

Interesting to know others are doing that.

[MarkBC]

That's hilarious. I actually thought about doing it that way but am worried about getting a bunch of dust in there. I even considered doing a filtered vent or something.

Interesting to know others are doing that.

 

Thank you for not calling me an irresponsible reckless daredevil lunatic.

 

I haven't noticed much dust...but I only keep "rugged" stuff in that under-couch storage, and I have a high tolerance for filth anyway.

I've had rodents (squirrels, sage rats) come in (or at least poke their heads through) the driver-side turnbuckle access vents (which are open to the living space) a couple of times, so if I stored food under the couch rodent access there through the open vent might be a concern.

[Ethergore]

What's camping without wild life?

[DesertDave]

What batteries do you have to get 300 ah?

I have (2) Lifeline GPL-6CT batteries, they are 6 volt AGM batteries, with the same footprint as group 24 12V batteries, but a lot taller, nearly 13" tall.  They fit into the drivers rear corner spot that FWC provides in their front dinette models.  I expect they would easily fit into most of the other spots that FWC can provide dual batteries.

 

I think they are really great, except for their weight and their price.  90 lbs each and you don't want to know.

[billharr]

I have (2) Lifeline GPL-6CT batteries, they are 6 volt AGM batteries, with the same footprint as group 24 12V batteries, but a lot taller, nearly 13" tall.  They fit into the drivers rear corner spot that FWC provides in their front dinette models.  I expect they would easily fit into most of the other spots that FWC can provide dual batteries.

 

I think they are really great, except for their weight and their price.  90 lbs each and you don't want to know.

  

I looked about 10 minutes ago.  Just got my breath back, you are right I did not want to know. Hope those batteries last a long time.

[Ethergore]

So I did more testing last night just to be redundant. Maybe you guys can let me know if I'm interpreting this right.

Battery- tested cold after sitting got 12.5 volts. (Wet cell) with air running, defroster on, high beams on, radio on I was at 12.3 and it slowly dropped to 12 over like 5 minutes. On cranking the battery never went below 12. To me, this is battery OK.

Alternator- At startup it sits at 13.7v (right after the load test). One it ran a while it sat at 13.5. From here on no matter what load I put on it it stayed at 13.5. From what everyone at tundra solutions this is perfect. Alternator OK.

Voltage drop- this is where I'm confused. If I disconnect the camper from the truck and test at the starting battery and then the plug I get 13.5 and 13.4 (small drop). If I leave everything connected and running I get 13.5 v at the starting battery and only 12.8v at the aux battery. So does this mean I have voltage drop our is it normal to read a different voltage across the length of the circuit depending on how close or far I am to the higher voltage battery? Seems like this is normal but can someone confirm?

Cycling of separator- I wanted to pinpoint at what voltage my separator will want to "cycle." I got halfway through this test but basically I am draining my battery a point at a time and seeing how low the voltage has to be for the system to want to separate the batteries. So far I'm at 12.3 with a load (the refrigerator) on and no cycling.

In addition, I have accessed my solar preslwiring in the roof and cabinet and lengthened my wires to reach my charge controller. Got the roof plug coming in today and mc4 connectors coming tomorrow.

Everything is coming down to the line since I'm leaving for 17 days on Friday. Wish me luck.

Oh ya. I'm consider springing for 2 six volt batteries if you guys have recommendations. The only place I've found local carries UPG for $210 each. Are these any good? They say they are made in "Asia." Us this Chinese crap or Japanese ggoodness?

[Ethergore]

Actually. I take it back. I called the place and they have Deka for $220 a piece. I think I'm pulling the trigger. US made goodness.

[PaulT]

Lurker who just registered to forum. Had to as DC power is one if my favorite subjects as a ham and as a new Hawk owner, I am trying to learn to live with the power I have.

Camped at Clear Lake, Oregon the last couple of days w/o hookups and lots of tall trees that limited solar charging. Unit sat without truck running for two days. Temp in high 80's during day. My 2 AGM batteries did fine as judged by how everything worked.

Zamp solar controller indicated batteries were down to 11.9 volts but FWC battery monitor LEDs indicated charge just dropped to half power. Noticed isolator relay cycling after starting truck but no indication on Zamp meter that charging was cycling. 100 watt panel charged at 6+ amps when stopped in full sun about noon. Plugged into AC on arrival in Hillsboro and finished charging.

As to measuring voltage drop, Ethergore's experience is normal. Voltage drop must be measured under load and is determined by wire size, length, and current being carried. There are apps for Apple and Android that help you pick a wire size for the current, run length, and allowable voltage drop. Pay attention to run length. Double the length of the wire run because you have to account for the return path.

This is a great forum. I have learned lots from the posts that helped me set up my Tundra and choose options for the camper.

Thanks,
Paul

[Ethergore]

Thanks for commenting Paul! I'm glad you let me know the correct way to measure voltage drop. I was thinking it was impossible to not have drop in that long of a run of a smaller gauge wire. Upon reading I found a nice voltage drop calculator if anyone wants to use it:
http://nooutage.com/vdrop.htm

In case anyone is interested I pulled the trigger on two Deka gc2 batteries with 200 ah each. I also accessed the prewiring for my solar but decided I will wait until I have a second panel to permanently mount it to the roof for instances where I park in shade. For now, i installed a plug on the side of my camper through the wood and ordered some mc4 connectors to make cables. I think my next upgrade will be a solar charger controller with smart charging to top off my batteries after my alternator does all the bulk charging, after that another panel should help me to match my energy usage.

All update on if the problem is solved after my trip.