battery questions

[Half Ton Heavy]

I've not figured out *exactly* what the system is going to look like yet. A 2506 is pretty limited on space, the battery will fit in a a group 31 box, and likely will live on the tongue, the converter will either be the WFCO lithium replacement , or if I want to spend the cash, a victron 2000VA mounted in my limited forward space. In that same space, a renogy dc/dc charger, and a MPPT controller, and conventional (2K) inverter if I do not go the victron route.

Right now, I have a very weird plumbing issue that has to get sorted first. Going in to the original selling dealership to see if they can sort it out. It's just plain weird. The shower and the toilet work, but nothing else does, with the exception of the kitchen sink which is at maybe 40%. But hot and cold work great in the shower.

[Mikec557]

Originally Posted by TitanMike

Rarely does the trailer sit unused for more than a couple weeks except for current state of affairs. When using TT, and shutoff module over ridden, any cell balancing that needs done is.

I thought FLA batteries needed balancing, which is performed by the charger/converter, and that with lithium batteries we turn off balancing and let the lithium on board battery management system (BMS) take care of that. Hmmm, even as I type that I'm thinking I turned it off in my MPPT solar charge controller, not the PD charger/converter. Maybe I just answered my own question.. Now I have to look for my PD91xxL manual. But since it was made for lithium batteries I would have thought it would have disabled any balancing feature it might have had for FLA.

Thanks. Now I have something to do on these boring stay at home days. 😊

Mike

[Mikec557]

Originally Posted by Half Ton Heavy

...

Right now, I have a very weird plumbing issue that has to get sorted first. Going in to the original selling dealership to see if they can sort it out. It's just plain weird. The shower and the toilet work, but nothing else does, with the exception of the kitchen sink which is at maybe 40%. But hot and cold work great in the shower.

HTH
That plumbing issue sounds like something I've never read about before. Would you let us know what you find out about it... in a new thread of course so we don't hijack this one

Thanks
Mike

[TitanMike]

Originally Posted by Mikec557

I thought FLA batteries needed balancing, which is performed by the charger/converter, and that with lithium batteries we turn off balancing and let the lithium on board battery management system (BMS) take care of that. Hmmm, even as I type that I'm thinking I turned it off in my MPPT solar charge controller, not the PD charger/converter. Maybe I just answered my own question.. Now I have to look for my PD91xxL manual. But since it was made for lithium batteries I would have thought it would have disabled any balancing feature it might have had for FLA.

Thanks. Now I have something to do on these boring stay at home days. ��

Mike

I think you have balancing confused with equalization. FLA's need equalization which is just a controlled overcharge in order to bring up cells to the same state of charge.

In a Lithium battery cell balancing is handled by the BMS. Unlike a FLA battery, once a Lithium cell in a series connection reaches full charge no more current flows through it. The BMS keeps a charging current flowing to the low cells even though the rest may be fully charged. Perhaps an over simplification of the process but that's the general idea.

With a Lithium battery, it just needs to reach a voltage high enough for the BMS to balance cells which is usually 14.4-14.6 v. The PD 91xxL converter has only one output voltage---------14.6. No other modes with their respective voltages.


Cell imbalance occurs as the slight differences in cell construction or quality allows some cells to self discharge more than the others or have their individual capacity degrade over multiple discharge cycles. The more attention to detail by the manufacturer, using high quality matched cells, the less this is a problem and even then a good BMS handles the issue.

In the end, and based on conversations with BB staff, as long as Battleborn batteries are allowed to fully charge periodically, loss of capacity to cell imbalance is a non-issue.

[Dwilcox]

One thing I have not seen mentioned is is there a heat strip for your refrigerator doors? If so it will suck your batteries down in a hurry. If there is most are attached to the light circuit, some add a switch to keep the light and some will just unplug the light circuit. I don't boondock enough to want to add the switch so on the few overnights I just unplug it.

[babock]

Mine is snipped permanently. I never get any frosting.

Originally Posted by Dwilcox

One thing I have not seen mentioned is is there a heat strip for your refrigerator doors? If so it will suck your batteries down in a hurry. If there is most are attached to the light circuit, some add a switch to keep the light and some will just unplug the light circuit. I don't boondock enough to want to add the switch so on the few overnights I just unplug it.

[babock]

It's 5w. Not sure I would call that sucking but it is 10Ah in a day.

Originally Posted by Dwilcox

One thing I have not seen mentioned is is there a heat strip for your refrigerator doors? If so it will suck your batteries down in a hurry. .

[TitanMike]

Originally Posted by babock

It's 5w. Not sure I would call that sucking but it is 10Ah in a day.

I think that in many cases people blame a lot of low wattage items for "sucking batteries dry" when in reality their batteries have lost more capacity than they realize. What used to be a couple hundred amp hour capacity may be half (or less) due to the usual battery killers (deep cycling, not fully recharging, etc).

[babock]

Yep...all those people that think their 7 year old battery still works fine!

Originally Posted by TitanMike

I think that in many cases people blame a lot of low wattage items for "sucking batteries dry" when in reality their batteries have lost more capacity than they realize. What used to be a couple hundred amp hour capacity may be half (or less) due to the usual battery killers (deep cycling, not fully recharging, etc).

[Mikec557]

I think people would be surprised how much power they actually use, if only they knew. After I installed the BMV-712 and started checking the draw on various items I was amazed we still had battery power in the morning (given the batteries from the dealer). I started making a list of items and their draw and then decided it was easier to upgrade the battery bank than try to budget.

On a related topic.. we were in a cool/cold nights location and needed a little warmth at night. We decided to use an electric mattress pad, queen size with two controllers, instead of the furnace. On hookups it's a no-brainer. While boondocking we needed full sun on the 300 watts of solar panels to recharge. Including the cpap, my side of the bed on 3 all night, my wife's side less, and all the parasitic draws we would use 40-50ah each night.

I guess that's a long way of saying, figure out your needs and build your battery bank to give you 2-3 days of power. Then figure out how you're going to recharge, be it genset or solar or a combination.

Mike

[chriscowles]

On the subject of charging the battery with the stock converter, how does one know if the stock WFCO WF-8955 is or is not using bulk charge, and for how long?

I have a standard (not clamp-on) AC/DC multi-meter, and the display screen on my Progressive Dynamics EMS-HW30C shows AC current being drawn. If all AC loads other than the converter are shut off, and all DC loads are shut off, can I relate the AC current drawn to reflect the DC current delivered to the battery, at least as an indicator of range, if not an actual measurement?

[HONDAMAN174]

Originally Posted by chriscowles

On the subject of charging the battery with the stock converter, how does one know if the stock WFCO WF-8955 is or is not using bulk charge, and for how long?

I have a standard (not clamp-on) AC/DC multi-meter, and the display screen on my Progressive Dynamics EMS-HW30C shows AC current being drawn. If all AC loads other than the converter are shut off, and all DC loads are shut off, can I relate the AC current drawn to reflect the DC current delivered to the battery, at least as an indicator of range, if not an actual measurement?

No- you can not related AC draw to DC usage.

One way I could tell was using a voltage readout thru my 12v socket. It never went above 13.6 even after my batteries were dead from being left on at the dealer. That’s when I knew my bulk mode wasn’t working so I switch to a PD converter and all is well.

BTW- progressive industries told me their ammeter is not 100% accurate. More like 70%. Did my own testing on my equipment and came back with 66%. So I take my reading and subtract 1/3 of it for my draw. I also put an ammeter on my DC side to track what the converter is putting out.

[babock]

Originally Posted by chriscowles

On the subject of charging the battery with the stock converter, how does one know if the stock WFCO WF-8955 is or is not using bulk charge, and for how long?

I have a standard (not clamp-on) AC/DC multi-meter, and the display screen on my Progressive Dynamics EMS-HW30C shows AC current being drawn. If all AC loads other than the converter are shut off, and all DC loads are shut off, can I relate the AC current drawn to reflect the DC current delivered to the battery, at least as an indicator of range, if not an actual measurement?

You can measure your voltage and get a good idea. When you are in bulk mode it try to to put as much current as the converter is capable of until the voltage at the converter reaches between 14.2 and 14.4V. At that point it switches into absorption which is 13.6.

The problem with most RVs is that the converter is far from the batteries so you may have over 0.5v of voltage drop during bulk so the converter sees 14.2 while that battery only is seeing 13.7 so the converter drops out of bulk early.

If you really want to see how your converter is charging your battery, buy a Victron battery monitor. Don't waste your time with a monitor that only measures voltage.

[tomkatb]

My batteries seldom go below 50%. The converter has gone into bulk only once.

When it does there is a large cooling fan in it that is really noisy. Sort of concerned us the one time it started. Was the spring start up when our batteries were the lowest ever.

The DW and I searched for a half hour to discover the source. Then it went off.

I should purchase a better converter.

[babock]

Originally Posted by tomkatb

I should purchase a better converter.

And increase the wire gauge. Better yet, put your new converter right next to your batteries.

[chriscowles]

Originally Posted by babock

And increase the wire gauge. Better yet, put your new converter right next to your batteries.

On the topic of wire gauge, we bought the rooftop solar prewire option on our 2507S. Anthony Yoder from Rockwood says "... From the controller to the battery [they] run 8 gauge. That is what the solar company [GoPower] suggests ...".

I haven't done anything with that yet but that's probably inadequate for a solar system, especially since the controller is intended to be mounted half-way back in the trailer, next to the refrigerator. The voltage loss will be substantial. However, that 8 AWG wire is in addition to the standard wire from the battery to the converter. I can connect them in parallel for a substantial increase in capacity without having drop the insulated underbelly.

What gauge wire should I use, ideally, for a 55A charger? The distance to the battery is 15' or maybe a bit more, considering twist and turns from one point to the other.

[Half Ton Heavy]

Originally Posted by chriscowles

On the topic of wire gauge, we bought the rooftop solar prewire option on our 2507S. Anthony Yoder from Rockwood says "... From the controller to the battery [they] run 8 gauge. That is what the solar company [GoPower] suggests ...".

I haven't done anything with that yet but that's probably inadequate for a solar system, especially since the controller is intended to be mounted half-way back in the trailer, next to the refrigerator. The voltage loss will be substantial. However, that 8 AWG wire is in addition to the standard wire from the battery to the converter. I can connect them in parallel for a substantial increase in capacity without having drop the insulated underbelly.

What gauge wire should I use, ideally, for a 55A charger? The distance to the battery is 15' or maybe a bit more, considering twist and turns from one point to the other.

Putting panels in series would raise the voltage ( and therefore lower current) from the pv feed. Put the scc close the battery.(Assuming prep has wires going close to the battery)

[babock]

Originally Posted by chriscowles

On the topic of wire gauge, we bought the rooftop solar prewire option on our 2507S. Anthony Yoder from Rockwood says "... From the controller to the battery [they] run 8 gauge. That is what the solar company [GoPower] suggests ...".

I haven't done anything with that yet but that's probably inadequate for a solar system, especially since the controller is intended to be mounted half-way back in the trailer, next to the refrigerator. The voltage loss will be substantial. However, that 8 AWG wire is in addition to the standard wire from the battery to the converter. I can connect them in parallel for a substantial increase in capacity without having drop the insulated underbelly.

What gauge wire should I use, ideally, for a 55A charger? The distance to the battery is 15' or maybe a bit more, considering twist and turns from one point to the other.

Calculate your voltage drop and keep it 2% or lower. That may require 1/0 AWG wire depending on how long the run is.

As far as the solar controller goes, try to keep it as close to the battery as possible. If you can use a solar controller that has remote voltage sensing of the battery, that will take care of the voltage drop for you. A Victron solar controller along with a BMV monitor will get you that remote voltage sensing.

[TitanMike]

Originally Posted by chriscowles

.What gauge wire should I use, ideally, for a 55A charger? The distance to the battery is 15' or maybe a bit more, considering twist and turns from one point to the other.

I would run the largest wire that fits the terminals on your converter. THAT will depend on the brand.

If forced to use smaller wire sizes you can achieve the goal of <2% voltage drop with #4 Awg wire and use the chassis for the negative side connection to the battery. #4 awg wire can be run up to 20 feet at 55 amp (13.8 volts) and stay under the 2% limit. If you do this be sure to upgrade the wires connecting to the frame/chassis as well and make sure to remove paint where connections are made.

[cl733]

Originally Posted by Venomos

First time poster and have searched through the FAQ's and quite a few threads... We have had our 2019 Salem Hemisphere Hyper-Lyte 22RBHL camper for a little over a year. We have had all kinds of electrical gremlins or so I think. We can't get the batteries to last overnight with the furnace set to 60. We have the Sterling batteries, 2 of them, P/N 24RV-90 ... I'm thinking these are just the dual purpose batteries and not true deep cycle. I'm looking at replacing these with a Group 31 series just to ensure the wife is comfortable at night.... We all know how important that is....


Any recommendations on brand? And are these the same size so they will fit into the battery boxes already there or would I have to get new ones? I'm also thinking on getting a solar panel since my camper is prewired for solar....

I do have a pair of Costco, IPower by Yahama, generators that are rated at 1600 watts running. I use these to recharge the batteries but I'm fairly certain they are pretty much done. We get about maybe 4-4.5 hours of furnace use overnight if we are lucky... I think I need a battery charge meter but I'm not sure what is drawing so much that it kills the batteries that fast.


Any pointers on what I should be looking at? I know the Dometic Fridge is running off gas, or so I hope, and it is set to auto, so should i take it off auto? The furnace is the only thing going at night as far as i can tell.

So my question is this... would Group 31 batteries improve the longevity of the heating situation or should I go a different route?
Also, I keep my trailer plugged in when we are not camping. I had it wired for a 30 amp circuit that goes into the main power box at the meter on it's own fuse, if that makes sense. I can run my A/C without any issues in the house so I guess it works. I had a licensed electrician upgrade my fuse panel in the house and wire that 30 amp plug all by itself.
Sorry for all the questions but this battery issue has got me all sorts of in the doghouse with wife....


Thanks all...

If you bought a victron battery monitor you can tell how much power every light or appliance takes to run the minute you switch it on,
I dont think they even make a fridge that runs off of 12v any more, as they take way too much power to run on 12v, and your fridge will probably run a month on a pair of batteries, if set to gas, or even to auto.
Have you got your antenna booster turned to on, you could have it on and not even know its on, if you do the math on how fast your batteries are going dead, you either have a larger draw on batteries than you think, or your batteries are not in very good shape, have you considered a pair of 6v batteries