anoyther strange one from Ted battery in rv

[wilsonintexas]

I have been in Alaska for 3 years helping my daughter. I picked up an RV for the trip back to Texas with her big dog (150 pounds of fur).

The RV House batteries are currently 2 6v batgteries, and they do not last the night running the furnace anymore.

I am thinking that a set of lipos might be a way to go, and then I could reuse them in a power chair that I have for my daughter down in Texas.

I picked up a Hyperion 0730I charger.

I am comfortable making up a batgtery pack. If I replace the batteries with the new battery pack, the alternator will try to charge them lke a normal lead battery.

I am not sure how best to wire the new pack into the RV.

Do I need some large diodes so the current can only flow out of the pack, and not back in to charge them and them wire up the hyperion to motor battery and charge it up when I have the motor running?

and a second question,

I am not limited by size (for now)

What is the current best buy for the batteries for the pack?

[Burgerman]

You should have got a PL8 as the hyperion has only 1/3rd the balance power, and they seem to be fragile. And I no longer know what firware, settings ets to use on those. However...

The best cells to use in the chair depends on a number of things, and how much work you want to do insulating. And exactly what space you have. It needs careful measuring and careful thought. As for the RV, then it will try to charge them. Is it 12 or 24V? And what does the alternator actually put out? As you start from cold, and when warmed up, and driving? What is the max load you will put on the batteries? Remembering that you are going to crank the van in winter... Since you will need diodes that can do 4 or 500 amps if you choose those to stop the alternator charging the lithium.

If it were me I would stick a couple of cheap massive lead bricks in the RV and worry about the chair later.

[wilsonintexas]

You should have got a PL8 as the hyperion has only 1/3rd the balance power, and they seem to be fragile. And I no longer know what firware, settings ets to use on those. However...

The best cells to use in the chair depends on a number of things, and how much work you want to do insulating. And exactly what space you have. It needs careful measuring and careful thought. As for the RV, then it will try to charge them. Is it 12 or 24V? And what does the alternator actually put out? As you start from cold, and when warmed up, and driving? What is the max load you will put on the batteries? Remembering that you are going to crank the van in winter... Since you will need diodes that can do 4 or 500 amps if you choose those to stop the alternator charging the lithium.

If it were me I would stick a couple of cheap massive lead bricks in the RV and worry about the chair later.

The rv is 12 volt. Right now I have 2 6v deep cycle batteries in it. I have space for them. A lot of people run 6 volt marine batteries paired up to get a little more ah.

The rv is built on a Fod chassi, I think that I have at least 100 if not 150 amps from the alternator. I bought it used and do not have the full specs.

The max load on the batteries is running the blower fan for the furnace and lights. But I put led bulbs in, so they do not draw much. I do not really know current draw (sorry not much help there)

The current wiring has two sets of batteries. The engine battery is only used to start the engine.

The second set powers the rv interior. They have a set of diodes built in so you cannot discharge the motor battery. Even if you run the rv house batteries down the engine battery starts the rv.

The rv house batteries are currently wired to charge in one of 3 ways:

1) with the motor running, at the alternator amps
2) when I plug in the RV there is a transformer that runs the 12 volt things (lights, furnace, radio....) it also has a charging circuite that charges the house batteries
3) If I start the generator it provides 120 volts for the microwave, roof ac, and I can run the refrigerator on 120 or propane.


I read your post on lead batteries, the Odessey 1500 is available here in Alaska for $270 (us) If I put in 2 I am at $540..... in that range I can start to build up a lithium pack......... and maybe get more life from them.

I have several inverters that I can run to get 120 from the house batteries.

I installed a hospital bed in the back that can be raised and lowered for my daughtger. I have a 1000w inverter to power it. I also have some smaller ones to power my cpap, and when I shoot aurra I use an inverter to run the computer. (I miss the old days when I could run the computer on 12 volts)

I can get an adapter for my cpap to run off of 12 volts. But the inverter was easy.

[Burgerman]

If you can make sure your alternator doesent charge it, then in this situation I may temporarily use a BMS that wont allow anything to exceed 3.55V on a 4S lithium pack. The problem you have is that you want to then fit these in a powerchair. As long as the BMS hasnt already ruined them. So you need 8 cells or multiples of 8 that allows you to get the most Ah into a powerchair as possible. That wont give you a big enough pack for an RV though, I think. And you better be sure they will fit the chair properly.

[wilsonintexas]

I have found some 6 volt golf cart batteries for $114 each that give me 220 ah for a 20 hour rating....... I may do it that way for now.
it avoids the problem of redesigning the charging systems that geed toe current 12 volt setup.

[LROBBINS]

One difference between the RV and a chair to take account of is that a chair has very variable, and at times, very high, current draw so internal resistance and Peukert effect are very important. Your RV use, just running essentially constant moderate drain devices, does not have that problem. Hence, the cheaper AGM batteries, unsuitable for a chair, may be a perfectly good choice for the RV.

[Burgerman]

And of course theres another huge difference. You have space. And weight isnt really an issue. So can choose huge but cheap batteries lead and win big for a dozen reasons. And to make them last a decade, and always be full when unused, fit a 13.3 to 13.4v regulated 70W to 100W solar panel on the roof. Or bigger if you want a top up during the day when in use.

Same reason I would buy a few massive but cheap lower quality batteries for a solar system. Average discharge level is low with oversized battery, so they last very well even if only cheap leasure type batteries. And because you have a bigger reserve for the odd heavy use days or no sun for a few days. And because the bigger the battery the less difference peukert/resistance makes. Of course where space matters, and I want good cycle life and performance from small batteries, then no choice. MK, Odyssey etc.

[wilsonintexas]

I PICKED UP A SOLAR PANEL THAT I HAVE TO MOUNT. I ALSO HAVE TO VERIFY HOW I CAN RUN THE POWER. I HAVE POWER TO THE ROOF FOR CONNECTING MY CAMERA, I NEED TO SEE THE EASIEST WAY TO CONNECT IT TO THE BATTERIES AND KEEP ALL OF THEM CHARGED.

I HAVE PLENTY OF CONNECTIONS TO THE HOUSE BATTERIES, BUT THEY HAVE A DIODE BLOCKING THEM FROM PROVIDING POWER TO THE ENGINE BATTERY. THERE ARE SOME DEVICES THAT CAN SWITCH BETWEEN CAR AND HOUSE, LIKE THE RADIO, BUT THAT WIRING IS NOT EQSY TO GET TO.

I THINK THAT I WILL END UP RUNNING A NEW LINE TO THE CAR BATTERY AND RUN IT UP TO THE CABINET THAT I FEED POWER UP TO THE ROOF.

I WILL PROBABLY GET GOLF CART BATTGERIES, SINCE I WANT TO RUN THE FURNACE AND CPAP ALL NIGHT. AT LEAST THEY ARE DEEP CYCLE.

(SORRY ABOUT CAPS, KEYBOARD STUCK.....)

[wilsonintexas]

I just looked at the "solar battery maintainer" that I picked up locally. It is only 2.4 watts..... so it would barely maintain the batteries. My dad had a few much larger panels (2 ft by 3 foot) at his farm. I will try them when I get down there in a few months to see if they are still good.I know that at least one of them are. he had them set up to charge batteries and ran a small pump to circulate water through some home made solar collectors. I think I remember that he had a battery charger on one of them. I will have to see if it is still there.

I just checked the voltage of the solar cell by placing it is Alaska sun. It read 22.5 volts. way to high.

I have a few adjustable voltage regulators. I will try one and adjust the voltage to 13.4 volts. I will have to see if it keeps a stable voltage when there is shade and the solar cell .

If that does not work I will have to get a better one later. Why can it never be easy?

I did get both mf my current batteries to charge on a decent battery charger. I am going to have the local Battgeries Plus shop run a load test on them and see what shape they are in.

[Burgerman]

I just looked at the "solar battery maintainer" that I picked up locally. It is only 2.4 watts..... so it would barely maintain the batteries.

You will never get 2.4 watts even for 1 hour per day in high summer unless the panel is aimed directly at the sun. And is kept cool. At best it will barely do anything worthwile in summer and nothing at all in the 6 colder months.

My dad had a few much larger panels (2 ft by 3 foot) at his farm. I will try them when I get down there in a few months to see if they are still good.I know that at least one of them are. he had them set up to charge batteries and ran a small pump to circulate water through some home made solar collectors. I think I remember that he had a battery charger on one of them. I will have to see if it is still there.

Unless modern, those will be about 30 to 40 watts. Adequate for maintaining a disconnected battery all year. With a PROPER solar mppt tracking charger. With just a regulator you will waste about 2/3rds the panels power.

I just checked the voltage of the solar cell by placing it is Alaska sun. It read 22.5 volts. way to high.

It doesent work like that. As soon as you load the panel, that voltage drops, a lot! If the panel is putting out about 22v then its a 12 or 18 volt type panel. But the actual output power depends on tracking peak watts. This means the panel voltage for maximim output varies due to temperature, angle to sun etc. So you need a mppt charger! It allows the panel to operate at max power, to make the best of weak sun, bad angles, cloud etc. And to put out the correct voltage for long term float charging.

I have a few adjustable voltage regulators. I will try one and adjust the voltage to 13.4 volts. I will have to see if it keeps a stable voltage when there is shade and the solar cell .

It will. But you will be wasting most of the panels power.

If that does not work I will have to get a better one later. Why can it never be easy?

It is!

I did get both mf my current batteries to charge on a decent battery charger. I am going to have the local Battgeries Plus shop run a load test on them and see what shape they are in.

What do you expect that to tell you? Load testing can only give a very vague idea as to if they are completely ruined, o not. Unless its done scientifically and even then its debatable what you will do with the figure you get.

You need to measure Ah.
And internal resistance.
A load test mostly read peukert which isnt going to tell us much. But its a good way to convince punters to get a new battery for a car. Most NEW deep cycle batteries would "fail" a load test. Since they cant produce big amps as easily as a starter battery.

[wilsonintexas]

As always I learn a lot from you.....

The RV is probably going to be parked at the farm for storage. I will get a float charger and just plug it in.

If it ends up someplace else I will get a solar maintainer.

The farm is in southern Missouri.

I will also check the voltage with it plugged into shore power. It is supposed to have a battery charging circuite. I will have to see what it puts out.

Actually that will be easy. I will do it first thing in the morning. I put in a small digital volt meter so I just need to plug in the power and check the reading. , I do need to check it for accuracy against a voltmeter.

[Burgerman]

Make sure that shore power or maintainer, or solar, does LONG TERM float at 13.3 to 13.4V and not higher. Or lower... Higher like13.6 to 13.8 is great for finishing a charge, but cooks a battery long term. 13.3 to 13.4 is great for long term float. 13.2 or less causes some kind of grid corrosion. So be very careful for long term float.

My van is set to 13.33V and sits there all day long every day, 9 MONTHS OF THE YEAR, using a cheap 50 watt solar panel, and a cheap solar charge controller that allows output voltage to be set manually.
That works 9 months, but the panel is too small for nov, dec, jan. as theres inadequate solar energy in those 3 months. So a 100W panel is really needed just to get enough to combat the self discharge and vans systems.

[wilsonintexas]

I WILL DOUBLE CHECK THE POWER LEVEL AND LOOK INTO OPTIONS.

I SUSPECT THAT THERE IS A LARGE DIODE BETWEEN THE PRIMARY AND HOUSE BATTERIES. IF SO I MY PLAN TO CONNECT A SINGLE FLOAT CHARGER TO THE PRIMARY BATTERY MAY NOT WORK. I MAY NEED TO RUN JUMPERS BETWEEN THE PRIMARY AND HOUSE BATTERY WHEN PARKED. I WOULD PROBABLY WIRE IT UP TO A SWITCH AND SET IT UP ON THE DASH PANNEL.

I JUST DID A QUICK TEST:
VOLTAGES WITH EVERYTHING POWERED OFF
CAR BATTERY 12.2
HOUSE BATTERIES 13.19

I THEN PLUGGED THE RV INTO POWER AND TURNED THE POWER TO THE INTERNAL SYSTEMS

USING A VOLT METER I READ
- 12.20 VOLTS ON THE CAR BATGTE
-13.19 ON HOUSE BATTERIES
- MY VOLT GAGE READ 13.2

SO ASHORE POWER IS NOT DING WHAT I THOUGHT IT WAS GOING TO DO. which IS GOOD IN SOME WAYS.

NOW I CAN GET A CHARGER AND WIRE IT UP TO FLOAT THEM.

I WILL PROBABLY MAKE IT 2 CHARGERS, SO I DO NOT HAVE A SITUATION WHERE I AM DRAINING THE CAR BATTERY OR TRYING TO DRAW CURRENT FROM THE RV THROUGH THE FLOAT SYSTEM WHEN I START THE CAR.

I THINK THAT I HAVE SOME UNREGULATED POWER SUPPLIES THAT I CAN ADD ON THE ADJUSTABLE VOLTAGE REGULATORS TO SO I CAN GET THE 13.3-13.4 VOLTS YOU RECOMMEND.

I MAY LOOK INTO A LARGER UNITS THAT COULD ALSO CHARGE THEM AND THEN FLOAT THEM.

[wilsonintexas]

I WAS LOOKING ON EBAY I SAW THIS SOLAR CONTROLLER.

https://www.ebay.com/itm/30A-12V-24V-PW ... 48af92e63c

IT SAYS THAT THE FLOAT CHARGE IS ADJUSTABLE, BUT I DNO NOT SEE HOW THE CHARGE VOLTAGE AND THE FLOAT FOLTAGE ARE SET.

(IF I RUN THE BATTERIES DOWN DURING GTHE NIGHT, AND I WANT TO CHARGE IT THE NEXT DAY. )

I AM THINKING THAT I HAVE OPTIONS WITH THIS. I HAVE A 40 VOLT POWER SUPPLY THAT I CAN USE WHEN PLUGGED INTO SHORE POWER. iT COUYLD THEN BE FED INTO 2 OF THESE UNITS, ONE FOR EACH BATGTERY.

LATER I CAN ADD THE SOLAR PANELS AND JUST WIRE THEM IN.

I HAVE A FEW THINGS I AM LEAVING UP IN ALASKA I WILL GET A FEW ADJUSTABLE REGULATORS TO KEEP THEM AT FLOAT USING SMALLER TRANSORMERS. tHAT MAY SAVE THE 2 NEW SNOW MOBILE AND THE RIDING LAWN MOWER BATTERIES UNTIL I GET BACK TO DEAL WITH THEM IN A FEW MONTHS.

[Burgerman]

You need MPPT tracking, or you will get about 20 watts at best out of a 24v solar panel trying to charge a 12V battery.

You need it to be able to take maybe 8 volts up to 30V in, and FIND THE BEST VOLTAGE to get maximum watts from the panel. Then using its internal inverters, it converts this to your 13.3V. It wont or should not charge at 14.4 0r whatever since it cant know the difference between the battery running a fridge or an alarm, and not being full. So charge would never end. It charges by floating the battery at 13.4v.

I have a draw full of those cheap chinese things. They dont do what they say!

[wilsonintexas]

which one would you recommend?

[Burgerman]

I kept buying cheap ones until I found one that did everything right. Most were junk. This is cheap and cheerful. But been working 2 years and going good... https://www.ebay.co.uk/itm/LCD-10-20-30 ... WWWUeABBcw

I set 13.3V through 9 months of summer and 13.7V in the 3 or 4 worst months. And it still doesent keep up, not enough solar light or panel. Solar panels are weedythings.

In theory, a 2 watt panel would do the trick, in high summer if AIMED at the sun. As long as theres only a tiny draw by a vehicles electrics. But on modern vehicles thats not true. So even in summer its no use.

I bought a 12W panel. On the dashboard in full sun, it made 4 watts. Because of the glass. Lay it flat on the dash, and get 2 watts. For about 2 hours a day. Less the rest of the time. So obviously its could JUST keep a battery topped up in summer as long as no other drain. But take a cloudy day, and get a fraction of a watt... Night time zero. In winter its not even close.

So I put a 50 watt panel on the roof. That works great 9 months of the year. I suspect it needed to be a 100w panel to get 2 to 4 watts for a few hours per day in winter laid flat on the van roof. My van has a 140mW drain all day long and night due to all the electronics and the stupid ramp computer and radio recievers in the boot. So thats 2.8Ah a day lost. So your panel will need to be able to replace that in winter with about 6 hours of daylight and little sun. While being laid flat on the roof right when the sun is low in the sky... Thats almost 2 watts 24 hours per day. So your panel needs to make 8 watts minimum for 6 hours per day. A 50 watt panel doesent...

Here:
https://www.ebay.co.uk/itm/LCD-10-20-30 ... WWWUeABBcw

[wilsonintexas]

would I need 2 of them, one for each battery?

If I connected both batteries o one connector, I would be opening up a path for the house batteries to drain the car battery. (I think)

I am thinking that I could get two of them and an power supply (15-20 volts) that I will wire in so it comes on when I plug into shore power.

Later I can add on a solar panel

I am looking at the specs.

It says that the battery float is 13.8 volts. I did not see how to adjust it down.

[Burgerman]

If 12v batteries in parallel you need 1.
If 6v batteries in series you need 1.
If two seperate batteries not connected you need 2 and 2 panels.

You cant feed a solar charger from anything but solar panels. Its solar peak power voltage search tracking will not like it.

[wilsonintexas]

ok, then I may wait until get down south to test the solar panels before I buy the mpp modules.

Until them I found some battery chargers with 5 stage charging for $17. They should get me by until I get down south.

Most of the time the car will be charging the batteries.

[wilsonintexas]

It is so frustrating living in Alaska...... SHIPPING so many people refuse to ship here, because shipping to the remote areas is a challenge and expensive.

but I live outside of anchorage.


I had placed orders for some battery chargers for the RV and adjustable voltge buck converters (to be able o set a float voltage of 13.4 on 2 snow mobiles, a lawn tractor and a car that are all staying here.

The battery chargers have been removed, and the regulators shipped UPS ground (4-6 weeks)

I know that the buck converters are not the best, but I know that if the power drops they will come back on at the same voltage. If I went with something like the hyperion and the power dropped (which it will do at least once or twice over the winter) I will not have anyone here to press the buttons to start it at t he float charge again.

I will pick up dedicated chargers for the RV once I get down to Texas.

I am going to be wiring in electric brakes today, so I may run dedicated lines from each battery back to the drivers seat and put in plugs so I can easily hook up solar or plug in chargers later.

[wilsonintexas]

The movers came today and packed the main floor. They finish packing tomorrow and load the truck on Friday. I hope to be on the road to Texas Tuesday afternoon or Wen.

I did not get any chargers for the RV. But I have set up a few of the adjustable voltage power supplies and adjusted them to 13.42 volts. I have pulled the batteries from my snow machines and riding lawn mower and will put them on the workbench with a float charger. I will disconnect the negative lead of the car battery and put it on a float charger.

I plan on coming back around march or April to finish up the house and put it up for sale. I will probably fly up and drive my daughters car back down to Texas.

When I get to Texas I will work out a better system to charge and keep the batteries on float.

I will try to let you know how it goes, bt it will be crazy for a while once I get back home.

[wilsonintexas]

daaaaaaa

when I tested the voltage of the batteries plugged into shore power, I did not turn the switch that turned on the rv to run on batteries..... so the transformer was not charging gthe batteries.

Today I plugged in the RV and turned on power. The batteries were at 13.6 volts..... at least a decent charging voltage. They could have needed a charge.

Tomorrow I will see if it is still at 13.6 or if it has dropped.

If it is still high, I may look at the power transformer and see if I can adjust t he voltage so it floats the batteries at 13.4

if not I will be hooking up a separate float charger for storage.


I may also run a jumper from the house batteries to the motor battery while in sorage. That way I only need one float charger.

I also have to admit that I checked the fluid level on the batteries. All were low, and at least one cell had a little of the grid plates exposed. Not sure how long that has been going on. It is summer, so I do not expect cold weather starting issues for a while.....

I may pick up new batteries before I start the trip. But if not, I am bringing a decent charger and I have one of those boost starter packs. I will be sure it is charged. If nothing else, I will use the boost pack to start gthe generator and charge the batteries with the charger......

[wilsonintexas]

I may have found a solution to using a solar charger or battery maintainer for two sets of batteries.

Cole Hersee makes a smart battery isolator. It looks like a starter soloniod with a control module added to it. It can handle 200 amps. and 750 rush. In standby it draws 8 ma

It connects the batteries when one of them is above 13.2 volts. (either one) for 2 minutes.
It disconnects them when both are below 12.7 volts. for 1 minute.
It also has a boost function that lets you connect them.

In normal mode, you use the house batteries and it draws from both batteries, until they drop to 12.7 volts.
It then disconnects them.

when the engine starts and charges the motor battery back to 13.2, it engages to charge the house.

If on solar power, when the house are charged to 13.2, it will engage to charge the motor.

They have a second model that they say can handle 2 battery types I think you can set the engage point for each battery separately. That may allow lipo pack for house, and lead for motor, but not sure I would do that.

There are also similar ones that use mosfets instead of a relay. They are more expensive, but take less power to engage. They would also fail in a cascade if you draw to much power. With the solenoid relay, if you draw to much, the points may fuse, but your could release them with a good wack. It would work well enough to let you replace the solenoid which could be a standard car starter solenoid

The control unit is in a plastic module that bolts behind the solenoid.