Need Battery help plz

[godskid]

Dawg: the monitor you pointed to on Amazon. I'm trying to wrap my head around what I see in the pictures. Lower in the description, it states it includes:
1 x Battery monitor -- the round part with numbers & buttons to change reading
1 x Current sampler -- this is the 2 nuts & bolts, with a circuit board attached between them?
1 x 2 meters long cable -- is this the cable from the middle of the nut&bolt unit to the round monitor?
1 x English operation manual

And then any cables to and from the battery (per their wiring diagram) I provide myself. Right? (That's why you included the link to suggested cables.)

Ok -- if I've got that interpreted correctly -- does the nuts&bolts unit need to mount or sit on something? Or just float between its wires? (8G is probably stiff enough to hold them in mid air) Does it need electrical shielding?

------------------------
Also, I see that the cheaper (but lower amperage) 10A Fast Lithium Charger (LiFePO4) that's listed on the AmpedOutdoors site is out of stock. Any idea if they normally stock it? I'd just as soon get that one, since it's guaranteed to be compatible, it's cheaper, and since I'm never in a hurry to charge. Plus, they sell it even cheaper when it's bundled WITH the battery. I'll ask THEM if you don't know, off hand. How fast does your unit charge this battery, if you've tested it yet?

Deb (I had electrics years ago with my BS in Physics, but I never liked it much! I do computers instead.)

[saltydawg]

I suggest the victron charger, they pretty much make the best. I dont know that companies charger, but the victron you can set it exactly how you want it to work. That will ensure the longest possible life from the battery.

As for the monitor.
I would suggest using an anderson plug to connect to the battery so it's a no tool removal. Then on the trailer side you install the current sensor right at the ground block. So the wire goes battery neg to anderson, anderson to current sensor, current sensor to ground block. Then the other wire. Goes battery pos to Anderson. anderson to fuse block. Then a small wire from the current sensor to the positive.

The purpose on the anderson plug is it makes it very easy to unplug the battery to take it in the house. As we all know use a bolt or nut too many times and it wears out. You would not want to wear out the terminals on a 300 buck battery.
Yes you will need to make up a few cables . The ones from the battery to the plug. Then the other side of the plug to the fuse block and current sensor the a short one for the current sensor to the ground block.

Now as simple as your system is you could probably just put all the ground on the current sensor output side.

[saltydawg]

Yes The display wire just plugs on the current sensor you can put it where ever you want with in the length of the cable they give you.

The current sensor should be mounted. It comes with holes for screws.
No shielding needed.

With the 13 amp charger I have its 4.5 hours from dead to full. The lifepo4 will take a 40 amp charge. But 15 or so is best
The name is scott

[saltydawg]

Also -- how does that LiFePo type of battery differ from the two below, both of which I've already bought to run my cpap while in the teardrop. These two both have chargers and monitors built in, and are thus more "consumer friendly" ..... but maybe they're not strong enough to run the teardrop fan and lights. I only use the DC outputs on them.

https://smile.amazon.com/gp/product/B07PF9S9NY/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

https://smile.amazon.com/gp/product/B01M3S00H0/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Or this newer model they show me, would it suffice for the lead acid replacement, and run the fan and lights? It must have less power somehow, given that it's only $300 including charging & monitoring.https://smile.amazon.com/dp/B07VL7XYY6/ref=dp_prsubs_1

Those are lithium batteries but they are 18650 lipo type which have a charge life of 300 to 500 cycles. The first one has 20 amp hours of battery life. The second one (new) is 40. The issue is lipo is the battery type that like to blow up and catch fire. The old one could run the lights but with the cpap you will get one night of lights and cpap. You might get 2 out of the new one. The 60 amp hour will almost definitely get you 3 night lights and cpap. You just need to figure out how to plug the cpap into the tear drop

18650 are cheap they are 3.7 volts each about 2to 3 amp hour each. Pack 40 of them in a case in the right way you get 20 amp hours at about 12 volts but you have 40 connection that can go bad. You can buy 18650 batteries for like 2 bucks each for cheaper ones.

[saltydawg]

https://youtu.be/YuKF8XfCVKQ

Lithium battery and fire. Now lifepo4 is a different chemistry and the BMS in the battery protects it. It's also why you want to use a proper charger

[godskid]

https://youtu.be/YuKF8XfCVKQ

Lithium battery and fire. Now lifepo4 is a different chemistry and the BMS in the battery protects it. It's also why you want to use a proper charger

Oooo, that was fun! (for certain definitions of "fun" ) I already own the first two that I pointed to, but they have charging circuitry, I imagine. Those 2 are only for Cpap usage, as spares for each other. Do they also prefer a partial charge, when sitting for some months? Should I run them a bit, then NOT charge all the way till the next trip?


LiFePO4 does sound safer. I'll suss out the actual cabling I've already got in the trailer (climbing underneath, etc), and determine where to insert this into the circuitry. (while leaving the original empty battery box and 35A charger, for when I sell the unit).

I wonder how much hand strength an anderson connection requires to unplug it. Mine is lessening as I age. Maybe I'll find one somewhere and test pulling it apart.

I've got some of these (see URL) from another project. Is that wire small enough (or too large) for the "small wire from the current sensor to the positive"? Or perhaps I rig it so that wire doesn't get unplugged when I remove the battery to go inside the house.
https://smile.amazon.com/gp/product/B01N7CEV00

Thanks Scott!
Deb

[saltydawg]

https://youtu.be/YuKF8XfCVKQ

Lithium battery and fire. Now lifepo4 is a different chemistry and the BMS in the battery protects it. It's also why you want to use a proper charger

Oooo, that was fun! (for certain definitions of "fun" ) I already own the first two that I pointed to, but they have charging circuitry, I imagine. Those 2 are only for Cpap usage, as spares for each other. Do they also prefer a partial charge, when sitting for some months? Should I run them a bit, then NOT charge all the way till the next trip?


LiFePO4 does sound safer. I'll suss out the actual cabling I've already got in the trailer (climbing underneath, etc), and determine where to insert this into the circuitry. (while leaving the original empty battery box and 35A charger, for when I sell the unit).

I wonder how much hand strength an anderson connection requires to unplug it. Mine is lessening as I age. Maybe I'll find one somewhere and test pulling it apart.

I've got some of these (see URL) from another project. Is that wire small enough (or too large) for the "small wire from the current sensor to the positive"? Or perhaps I rig it so that wire doesn't get unplugged when I remove the battery to go inside the house.
https://smile.amazon.com/gp/product/B01N7CEV00

Thanks Scott!
Deb

If you connect like I said above the monitor would stay in the trailer. And its a very small wire needed to go to the positive, like 18 or 20 gauge small.

As for the anderson plug strength, they are a larger connection so there is plenty to grap hold of, and you can and should mount the trailer end one to a wall so it does not not flop around, so now you only need to hold one side. I would say they are harder to unplug than a reg cord connection, but not impossible. They do kind of lock, but you can pull and wiggle and it will come out a little at a time until they reach the point where they would just come out.

As for the other battery packs you have yes, discharge them a little. Say 20% or so so they are not sitting at full charge.

[saltydawg]

here is a decent but long winded video on anderson plugs. if you dont have 11 mins just jump to around 8 mins. it has info you like, esp with unplugging them.

https://www.youtube.com/watch?v=NmVAaGHRFXk

Oh the small 18 gauge wire can go to the fuse block it does not need to go to the battery pos

[godskid]

Thank you -- great video. AND it shows me that some kits come with handles, which I think I would need. Good stuff!

[godskid]

Can I use 12AWG wire and appropriately sized Anderson quick connects? The rest of the trailer wiring seems to be 12AWG, and would still be in the circuit. My only draws are the Fan-tastic fan and two lights. And usb plug points. I’m not sure where I started looking at 8gauge, but that seems to be overkill, and harder to work with. Am I okay with 12AWG?

[saltydawg]

Can I use 12AWG wire and appropriately sized Anderson quick connects? The rest of the trailer wiring seems to be 12AWG, and would still be in the circuit. My only draws are the Fan-tastic fan and two lights. And usb plug points. I’m not sure where I started looking at 8gauge, but that seems to be overkill, and harder to work with. Am I okay with 12AWG?

Your okay with 12 just make sure you fuse it in some way. if something where to short out the 80 amps the battery can give would melt the wire in a second. I would recommend using 10 and fusing it at 20 amps, yes the wire is over kill, but with 12 volt systems voltage drop is not our friend. I would also recommend the 8 until at least the anderson plug, because its going to be moved, plugged yanked on, might as well as have the first foot or what ever to the plug a larger stronger wire.

[MickinOz]

8 awg is around 10mm2.
Way overkill, in my opinion, assuming you are using copper wire. (All bets are off if you are using aluminium wire.)

My Renogy 20 amp solar charge controller will accept maximum wire size of 6mm2. That's 10awg.
12 AWG is 4mm2. I'm using that to connect battery, solar panel and fuse block.

[saltydawg]

8 awg is around 10mm2.
Way overkill, in my opinion, assuming you are using copper wire. (All bets are off if you are using aluminium wire.)

My Renogy 20 amp solar charge controller will accept maximum wire size of 6mm2. That's 10awg.
12 AWG is 4mm2. I'm using that to connect battery, solar panel and fuse block.

Sorry I am an electrician who used to do a lot of work on electrical for sailboats, so lots of solar and batteries. I always tended to make it future proof and as safe as possible.

The one that used to get me was people wanted solar on their boat, stores would tell them here is you 200 watts of panels and hook it up with 12 gauge. I measured at the panels around 17 to 18 volts, 30 feet of wire later 15 volts, thats in full sun. Amazing after I would run new wire and the system started working better I never had more than a half volt drop.

I have seen people run 50 feet of 18 gauge wire to the other end of the boat for a 2 amp fan, and then wonder why it never worked right. Of course it was only seeing 10 volts at the fan.

Dropping 3 or 4 volts on a 120 volt circuit, which is the max legal is one thing. dropping 2 volts on a 12 volt system is another.

[godskid]

So: I discovered the original problem with my old lead acid battery was that a GCFI circuit on the trailer's AC outlet was tripped (during some house power glitch). This prevented power reaching the old charger, and thus the 4 LEDs on some switches drained the battery. It charged back up okay, but I don't trust its life-length any more.

I've bought the 60A LiFePO4 battery from AmpedOutdoors. Also bought their charger, since it's warranted for their battery, and was discounted in price when bought together. AND it included a wiring harness.

I'm planning to install the new LiFePO4 battery at either AA or BB in PIC2 below - preferably BB, I think. Both the old battery and the old charger will be removed from the circuit. A local friend thinks the circuit is okay either way. Yes? (Q1)
https://drive.google.com/file/d/1gYhRyF ... sp=sharing

Here's the circuit I propose to install at BB.
https://drive.google.com/file/d/16sJeRY ... sp=sharing

Meter wiring requirement:
https://drive.google.com/file/d/1yvDwDm ... sp=sharing

Q2: As I show it, my charger attachment to the battery is separate from the meter. Am I supposed to charge THROUGH the meter, in order to register the charge that's on the battery?

Q3: The charger harness is 10AWG wire, and an Anderson connector (all came with it). Is a 10AWG wire with SAE connector sufficient for the 5-6A max draw, at my position Q in diagram? I can find those cables made up, and I know I can physically undo an SAE connector (used them before). I'd put a polarity reverser in the middle, so the two pieces here can mesh, with RED mating with RED.
https://smile.amazon.com/dp/B085HPJNXT/ ... BKGC13Z4NX
https://smile.amazon.com/dp/B083XMKJ8K/ ... B79NYV8TB6

Holler if I"m not making sense! And thank you!
Deb

[saltydawg]

Yes you can install the battery at aa. Yes you want the charger going thru the monitor. Using the small battery connect for your load should be fine. I think having a disconnect plug for the charger makes sense you can bring the charger inside when the battery needs to be charged. Then when its in the house its an easy to just plug the charger to the battery.

Yes I think you need to leave the fuse in there even thou I dont have it drawn on the below picture. Below is a very simple drawing, it does not have things like your fan but that is all existing wiring you should not need to mess with. If you want the charger on a switch that would be fine, that way you know that its off and not drawing any power when not charging. You can just hook the charger to the fuse box ( what your drawings labels devices ).