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PostPosted: July 23rd, 2017, 9:52 am 
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I read an internet thread where someone called Lifeline, and was told the PD charger was pretty optimal for their batteries.

I guess I see what you're saying about the voltage, but it still sounds to me like they're saying bulk mode is 14.4 up to 90% SOC, then it drops to 13.6 for what could be called absorption for hours, and then finally later on to the typical 13.2 float. Chart from PD:
Attachment:
File comment: PD charger voltage profile
image.gif
image.gif [ 47.02 KiB | Viewed 152 times ]

Now here's something that I really don't understand:

The other day I replaced my fridge's scorched power board with a Dinosaur board, and also added a new DC heating element.

Now we all know that using the DC mode is a battery killer at ~14 amps. But I figured, hey, I'm on shore power with a 45 amp capable PD converter-charger, so no problem doing a test run. After all, I can run fans and lights and the converter handles it all while the coach battery sits at a zero discharge rate.

But whenever I put the fridge into DC mode, my battery monitor instantly shows a 4 amp discharge! Which seems to tell me that the PD is only contributing 10 amps of DC. Wth?

EDIT: so later I tried again for longer, wondering if maybe the PD thought a battery was charging and it had to limit amps or something. After about a minute, the battery discharge rate had dropped to 2.2 amps, but I think it still should've been zero.

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Last edited by kdarling on July 23rd, 2017, 1:36 pm, edited 1 time in total.

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PostPosted: July 23rd, 2017, 10:22 am 
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Yes the voltage outputs of the PD charger look very close to a match for what Lifeline calls for.... at 77ºF. That's the potential catch. If your batteries are at a temperature other than 77ºF, the voltages called for are different (higher when colder; lower when hotter). Especially with the batteries in an outside compartment, there could be some big temperature swings. Even for mine, which are inside under the couch, they are typically quite a bit colder than 77ºF in the morning hours, when the charging tends to occur (using solar).

As far as I know the PD charger does not have available temperature compensated charging, so it won't be "right on" unless the batteries are at 77ºF. When a charger does have temp comp functionality, it's just a matter of attaching a small ring terminal or sensor to the battery post or case (depending on the style). The the charger's built in temp comp function will add or subtract at a certain rate (usually adjustable to match the rate the batteries want) so that the voltage is the *equivalent* of those original voltage settings at whatever temps the batteries are actually at. This might be 13.7 (vs. 14.3) if they are hot, or 15.0 (vs. 14.3) if they are cold. Since tenths of a volt count, it's a fairly large difference.

That's not to say there's no place for the PD charger. To my mind it's just about knowing what given charger can and can't do, and then deciding how it fits your use case/philosophy/etc.

Here is a chart showing the effect of temperature on charging voltage requirements (to be equivalent to the suggested ones at 77ºF). This is from the Lifeline Battery Manual.

Attachment:
voltage vs. temp.png
voltage vs. temp.png [ 64.4 KiB | Viewed 150 times ]

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PostPosted: July 24th, 2017, 10:06 am 
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Location: Santa Cruz
kdarling wrote:
But whenever I put the fridge into DC mode, my battery monitor instantly shows a 4 amp discharge! Which seems to tell me that the PD is only contributing 10 amps of DC. Wth?

EDIT: so later I tried again for longer, wondering if maybe the PD thought a battery was charging and it had to limit amps or something. After about a minute, the battery discharge rate had dropped to 2.2 amps, but I think it still should've been zero.


I think it should have been zero as well. Curious.... doesn't 14 amps sound a bit low for an electric heating element? That's less than 200w which just doesn't sound like much to me. But even if it's twice that, I would hope your charger would assume full duty of supplying power due to it's 45 amps rating.

What happens when you disconnect the bank?

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PostPosted: September 27th, 2017, 8:07 am 
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I copied and pasted this from the house battery not charging with engine running thread:

From me-

I have a 1995 chassis and a Trail Wagon label dated 6/96

"On another note, while looking for a spot for the new 1/0 negative cable I just installed, I discovered melted wire loom on both sides of engine exhaust manifolds where Chinook ran their wiring back to the house as it passed by the manifolds. The wiring itself was ok, but the loom was trashed. About 3 feet on the driver side and 2 feet on the passenger side. The ford OEM wiring for the chassis had a special wrap to protect it from the heat. The Chinook wiring was secured to the OEM wiring. I had some special wrap and covered those damaged areas."

I have a PD 4655 that is installed in the brown box below the sink area drawers. Looks like the 8ga positive wire running from the PD 4655 to the house battery solenoid is routed on the driver side frame and is in that melted loom that I wrapped with heat protective material.

If an owner has installed larger wire to replace the 8ga, where did you route it up into the converter area after leaving the frame area which make the run a lot shorter with larger wire.

Thanks

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PostPosted: September 27th, 2017, 11:55 am 
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reddingnative wrote:
If an owner has installed larger wire to replace the 8ga, where did you route it up into the converter area after leaving the frame area which make the run a lot shorter with larger wire.

Thanks


Just as a note: You'll want to be looking for replies from folks with pre-1997 units (at least). Reason I say that is that I believe in 1997 (maybe '96?) the house batteries were moved to an outside compartment that's basically under the couch/water heater area. So for that generation it's fairly easy to route a shorter/heavier cable along the wall behind the couch (whereas Chinook took it to the forward pillar, up the pillar and then aft *above* the long window, then down by where the sink area meets the shower, and then to the brown box. Something like a 30' run of 8AWG :shock: ).

That said, I did run a larger combiner wire on my '99, which essentially means I ran a larger wire from under the hood in the front/passenger corner (where the start [not house as i originally typed] battery is on my rig), over across the air cleaner/hood seam area (on the V-10), and then down sort of near the steering column, then along the driver's side frame rail under the rig to around the forward third of the couch, and then inside (my batteries are under the couch now). I did all that with 1/0 wire. So that might approximate the route you are looking to take. Chinook's original combiner wire took this same route basically (with a detour to the driver's side fender top for the original combiner, which I don't have there anymore). The wire was just in run-of-the-mill plastic loom, and was not melted or compromised. I did add more cushion clamps and other securements - plus new/better loom - since 1/0 is quite a bit heavier. I did buy a ~3' section of heat-resistant loom from Mcmaster Carr but I didn't turn out to need it.

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Last edited by Blue~Go on September 29th, 2017, 2:40 pm, edited 1 time in total.

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PostPosted: September 27th, 2017, 2:36 pm 
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I salvaged the generator's 6awg start cable to power the house. My story isn't really applicable, but for the sake of potential amusement, my bank is in the generator bay and the supply cable goes across the rig through the crossmember above the rear axle. I drilled a hole through the floor near the load center. There were already a few holes in the generator bay. Standard wire loom. 13 foot run.

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PostPosted: October 1st, 2017, 9:56 am 
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Ok-

I have a 1995 chassis and a 6/1996 Trail Wagon manufacturer date, but my Chinook charging wiring diagram is noted as pre-1996 which I have confirmed as correct.

So, couple questions:

What reference should we be using for voltage loss?

In looking at the routing of the existing 8ga wiring from the PD 4655 to the house battery, it would be an easy run with larger wiring and two improvements besides the larger wire.

- There is a Chinook installed old school solenoid on the firewall inside the engine compartment. This is controlled by the RED house power switch on the lower dash, left of the steering wheel. I'm thinking about replacing this solenoid with a remote battery switch. I could locate that battery switch somewhere near the PD 4655 and continue to use the existing Red on/off switch.

- The question here is there are two, directional 50 amp self re-setting fuses that are mounted near the house battery by the PS headlight. You have to remove the house battery to service them. There is about 2 feet of extra wiring that could be eliminated in the engine compartment. Is there an simple alternative in-line fusing method?

PD 4655________________to/from_____________Solenoid___________(50) Batt-Aux______Aux-Batt (50)_____________+House Batt

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PostPosted: October 1st, 2017, 11:06 am 
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I've never understood those self-resetting breakers (this isn't allowed in boating). What is the idea behind them? You have a "fuse should blow" situation on a regular basis and then they re-set? ??? I would think anything that would regularly "blow" would want to be corrected. If it's something that could conceivably blow at a bad time, there are breakers. For example, an anchor windlass on a boat might get jammed with a log or something (anchor on bottom catches log) and the load would cause the fuse to blow. But you don't want to be stuck adrift getting out tools to change a fuse. So that would typically be a breaker. You get the log unhooked flip the breaker and go on your merry way (but the breaker can't be automatically re-setting, and if it were I guess it would keep cycling while you dealt with the log... ugh).

Anyway, basically any fuse that will meet the AIC rating (on the battery side), and that will fit in the space will be fine. So of course an MRBF (aka terminal fuse) comes to mind on the battery (one thing I don't get: why is there a separate "aux" and "house" battery? What does that mean? I just have the start battery and the house bank (multiple house batteries but banked as one).

The closer the fuse to the source(s) of current the better (less unprotected wire). Of course the MRBF leaves no unprotected wire. Other fuses you might choose would be AMI/Midi, Maxi, Mega, or ANL. If you take a look on Blue Sea's website (or even easier to read, in their downloadable catalog) you can see what the AIC ratings are, fuse sizes available, and what the various holders physically look like (which can be a deciding factor). Many of these are also available from other companies if you prefer.

I don't have my brown box anymore (yay, gone!), but I *think* there were some built in fuses. I don't remember what they did or covered though, anymore (and I never paid that much attention as I knew that was going to be removed altogether).

On the '99 era, with the brown box under the sink counter, and the batteries essentially under the water heater, they were about 14 feet apart. But that didn't stop Chinook from using over 30' of wire (heh). Which would be okay if it were much larger. So in my layout just running the wire over to the outside wall, along the outside wall under the couch and behind the water tank, and then to the batteries would save half the run. And since it's not up in the walls, not too hard to deal with larger cable as well. Plus, as a side bonus, the old 8AWG gives you a nice, unused 8AWG cable up by the forward/driver pillar for some other purpose.

But I know yours runs a bit differently. If you know the length, plus the max amperage of the charger (and/or the loads, if they use the same wire like mine originally did), I could run a calc for you. Just realize that without temperature compensated charging, the charging voltage can only really be accurate if the battery is at 77ºF. The brown box style chargers never have temp comp as far as I know (one reason I put in a different charger). But that may not be a huge concern if you are running a single, not super expensive house battery that can be replaced without agony. Still good to fuse (or breaker) properly and eliminate any massive voltage drop, IMO.

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PostPosted: October 1st, 2017, 1:27 pm 
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Blue~Go wrote:
I've never understood those self-resetting breakers (this isn't allowed in boating). What is the idea behind them? You have a "fuse should blow" situation on a regular basis and then they re-set? ???


When I removed mine, one of them just fell apart in my hand, which forced me to notice that it was stuck (corroded) in the closed position. It was saved for comic relief, but I just checked my boxes of electrical discards and couldn't find it. BTW, it was protecting the house wire which had a melted loom where it passed the driver side exhaust manifold. That could have been interesting. Yeah, they're not the best. Not trying to instill fear, just sharing experience.

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PostPosted: October 1st, 2017, 1:41 pm 
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Mine were in okay shape when I took them out, but they looked cheap, and likely didn't have a very high (or any?) AIC rating.

Just in case it wasn't clear (to others), it's not that breakers aren't allowed in boating*; it's just that they can't be self-resetting. Both breakers and fuses are used commonly, just depending on what suits the job better.

BG

*By the way, one reason I mention boating is that for a long time the boating industry and public have had the ABYC (American Boating and Yachting Council). They publish sets of "best practice" standards for many different categories: From propane systems, to flotation/design, to electrical systems (and more). These are "living" standards with people constantly re-evaluating them and making changes when appropriate. They make a great "cookbook" approach to doing things in a thoughtful, safe way. They also take the real world into account and are not ridiculously unattainable, which is helpful.

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