Inverter and Battery capacity for washing machine

[Ho jo]

Greta my 1700 generator runs 8 hrs on 2 gals 50% load fuel now here 1.88 per gal. 1 hr for 2 wash loads 440w/hrs Microwave 700 watt 10 mins daily 117 w/hrs . 2 slice toaster 840 watts 4 slices 8 mins 112 w/hrs? E blanket 400 w/hrs nightly. DC rv loads pump leds propane fridge 300 w/hrs daily. TV and dvd 45 watts 4 hrs 180 w/hrs. 1110w/hrs (Please check my math) Batterys are us battery 1800 $85 each $15 core so actually $400. My travel trailer is on a permanent spot. So an isolator wouldn't work. 1110 w/hrs x1.5 1665 x 3 days 4995 @24 volts 208 amp hrs @ 12 volts 416. Amp hrs. Array size 1665 divided by 3.9 sun hrs 426 watts.Charge rate for 208* .10 21 amps times 24 500 watt array. Planned on 550 watts on 30 amp controller.

[Greta Gremlin]

Merging your current 12v system into a new 24v system might work..
What's your current 12v setup, brand of CC, battery ah?
Like you said, a major concern would be mixing old with new, I'm not sure when it is bad for batteries.
You might be able to if they haven't been heavily used, battery pros would know the right and wrong conditions.
If you go for that, you would still want access to your 12v needs if merging into a 24v system.

To make that possible, you could check into a DC to DC converter, that is 24v to 12v.

https://www.solarpaneltalk.com/forum/solar-panels-for-home/solar-panel-system-equipment/325288-24v-to-12v-conversion-20a-12v-draws-20a-24v-or-10a-24v

These have a wattage rating, and there are few design types but from what I've read the Buck converter type is the one you'd be looking for.
Essentially, one that converts 100% power with no losses.
That way you could utilize your 24v system for 12v also.
I don't know the consensus on using DC to DC converters here.
Though could perhaps save money if recommended by those who know.

4x 6v 208 ah batteries for $340 sounds suspicious, for 2x sounds right.
I'd guess $600-800 more likely.
You might have to pay a core charge as well for the batteries if you aren't bringing in any old ones.
May be why the price is so low, hard to say, also could be old stock of unused batteries or they may be low quality/short lifespan.
Have others had good results with these? Sounds to be Sam's Club Golf Cart batteries but still might be okay.

Your estimated 24v system:
550 watts -> 30/100 CC -> 24v 208ah

The estimated price of the 24v system comes out at:
$200 + $230 + $340 = $770

And for a 24v inverter probably between $500-800 .

So total system cost for equipment would be:
$770 + $500-800 = $1270-1570
Like mentioned, add around $200 for racking, wiring, wiring terminals, fusing, other miscellaneous expenses
Guess maybe $1500-$1800 total ($1300-1600 discounting your CC).
That inverter could potentially be half the price of your system, kind of a slap in the face.

Then the charger, I'm seeing about another $400 for a battery charger at 24v.
There are lots of battery chargers but some do not have equalization capabilities.
Additionally, some manufacturers recommended using a higher voltage for their batteries than some equalizing chargers are capable of producing.
If that's the case you could look into a variable DC power supply.
Here is some good information on that.

https://www.solarpaneltalk.com/forum/off-grid-solar/solar-living/18274-choosing-a-charger-that-can-equalize

https://www.sailnet.com/forums/electrical-systems/124434-needed-battery-charger-equalization-desulfation-mode.html

Make sure it can charge battery, some kinds of DC power supplies won't be adequate.

http://www.mastechpowersupply.com/linear-vs-switching-power-supply.html

If you go for a DC power supply, you'll want to contact manufacturer to ensure that it is capable.
An example of what might work for you. This power supply could also equalize your 12v batteries.

http://mastechpowersupply.com/volteq-power-supply-hy5020ex-50v-20a-over-voltage-over-current-protection.html

I would ask others to see if this is a reliable brand or not, as well as the site being trustworthy.
Using DC power supply is my plan if CC equalization isn't adequate.
With added charger, looks to be $1900-2200 total ($1700-2000 discounting your CC).
My prediction is that you'll probably end up spending more like $2000-2500 for a new 24v system in the long run.

Depends on what you're trying to do, but you might be able to spend that money on something better suited.
I bet there are some very interesting things you could do instead with $2000.
What kind of system are you wanting? Selling current equipment to help fund your new system is an additional option.
What kind of loads are you trying to run and for how long?

If the better-appliances-for-12v-inverter option won't work for you,
I'd say the next simplest solution, like what you have been doing, is using a generator for those temporary heavy loads.
For the $1500-$2200 of a new 24v system, you could a get good inverter generator for a $1000 and $500-1200 in potential fuel.
Some advertise they can run 8+ hours on 1 gallon powering 500 watts. That'd be like a 0.25 cents an hour to power it.
Or just translate expenses into fuel to power your current generator. $1500-2200/$2 a gallon for fuel = 750-1100 gallons.
How long would that allow you to do what you want to do?
Or look at it in terms of gasoline vs batteries
Can $400 worth of fuel outlast the $400 worth of batteries in a 24v system to do what you want it to do?

As for battery temp, sizing for lowest temp will offer the biggest cushion.
Whatever method you use to size it, if you change battery capacity, then panel size will need to be adjusted as well.
If you have a battery isolator, that could soften the blow during cold temps since you are using RV.

[Ho jo]

Thanks for the detailed reply very informative gonna take some time to sort it out.My batteries are 10 months old so probably not a good idea to add 2 more. I could leave my 400 watt battery panels on pwm for rv dc loads 300 wh daily. I.can get 2 275 gt panels (Craigslist) for less than 2 of the 100 watt panels I have now. I have a 30 amp 100 voc mppt cc. Could handle 2 of the panels at 38 voc in series. On 24 volts 30.5 vmp in parrelell would be to low so 2 at 550 watts is the limit. So 4 batteries 208 amp hr $340 2 panels $200 24 volt inverter$?? Charger Racking wiring fusing.Can get expensive even for a small system. On a different note something I hadn't accounted for. Average jan low Temps are 28f degrees. My lead acids at that temp have 70 percent capacity. So I have to a just for that. Wouldn't you use average. Or record low temperature?

[Greta Gremlin]

Since building a whole new system will get pricey quick, these might be some money-saving options you could look into.


12 VOLT Options

1a) Best case scenario, you have an accurate idea of load requirements.
Your washing may have a good enough PF to make a 12v 1000watt inverter work.
And the 1000 watt inverter is capable of covering needed surge loads.
This would only require buying a good 12v inverter.


1b) Getting good appliances instead of more solar power.
If the washing machine is your highest load, then an getting an energy efficient washing machine will probably outweigh the costs of a separate 24v system (panels, CC, batteries, inverter, wiring).
Just will have to make sure the PF is good on the new washing machine.
The same would go for any appliances that you might've used for the separate 24v system.
This would only require buying a 12v inverter and new washing machine (or any other compatible appliances).
In the long term, the appliances would probably last longer than the cost of new batteries for that higher voltage system as well as the maintenance and the more things that could go wrong on the new system.
Appliances also may give you a better warranty.

[Ho jo]

Greta Gremlin I'm in a rv so 12 volts for now. I have considered running the dc loads on my rv from my 12 volt 400 watt system. Then all inverted loads from a higher voltage and wattage system.

[Mike90250]

6kw @48 volts and 800 amp hrs
is there any thing it won't run.

Won't run a big whole house air cond & electric range.

[Ho jo]

6kw @48 volts and 800 amp hrs
is there any thing it won't run.

[Greta Gremlin]

Yes I've heard kilowatt meters aren't very good at showing peaks. A generator is how I've been running my machine. Just enlarging my system for running a washing machine wouldn't be a good idea. But with winter I need to grow my system any way. Just wondering if anyone knew how large of inverter and battery I would need.

I might need some correcting on this. Edit: Sunking has corrected this information on post #25 of this thread
For sizing your battery with inverter, you will want to consider two things; PF (power factor) and inverter efficiency.
I tested this on a mini fridge and the losses from PF alone is what steered me to 12 volt only appliances.

Not sure if PF is ever mentioned in-depth in the stickies.
this thread gives a good idea about what to expect from PF (8 year old thread).
https://www.solarpaneltalk.com/forum...-in-the-system

Following example given is based on that thread.
If your peak load is 783 watts, you'll want to check the PF to get a good idea of what it will draw in voltamps and not
watts.

Example, PF is 60%, then 783/.6 = 1305 voltamps

Then put in inverter efficiency.
Example, inverter efficiency is 80%, 1305/.8 = 1631 voltamps

783/.6/.8 = 1631
So an estimate may be 1631 voltamps being pulled during peak loads.

To get a true estimate you'll have to measure the PF on the appliance during both surge and continuous.
(Note: For my fridge test, I noticed PF is around 80-90% during surge but 50-60% for continuous. You may have similar
results on the washing machine so you might be able to cover that surge load with inverter.)
The inverter efficiency won't always be giving peak efficiency so may want to leave yourself some room for sizing
inverter there also.

Since the estimate was that 1631 voltamps were being pulled,
then sounds like an inverter rated 1000 continuous with 2000 surge would work.
Your generator rated at 2000 surge ran the washing machine fine, so that offers some confidence.
Though the peak load of 1631 voltamps may run longer than the inverter surge is capable of handling.(some can supply
surge no more than a second)
In which case the 1000/2000 inverter won't work. You may have to get an inverter than handles 1631 voltamps continuous.
Your generator was rated at 1700 continuous so it'll be hard to tell whether or not your 1631 voltamps are going to be
surge or continuous.
If committed to getting it to work, you may want to look into how long those peak loads go for.

I'm seeing most recommendations on the forum are not to go above 1000 watts for 12v.
Though I don't know if that recommendation is for surge or continuous.
If your set on safely running washing machine, might make sense to make the switch to 24V or even 48V if you're
enlarging your system.

[Mike90250]

Mike what size inverter

It's 6Kw 48V with 800ah battery. only registers about 300w running, but the reversals are real power hogs. I am pretty sure it's a inverter drive motor in the washer, to get all the speeds and directions.

[Paul Land]

I have an energy star front load washer (samsung), and it runs the drum about 4 revs each direction. When it reverses, I can hear the inverter grunt as the motor sucks juice. So mine has lots of peak loads - about every 90 sec as it reverses.

Yup! I have same 1 as you do. It sips H2o and juice hardly registers voltage on my transfer panels voltmeter

[Ho jo]

Mike what size inverter

[Ho jo]

Not sure about what uf etc capacitor; iI'd need or where to wire it in . guess its like my air compressor it has capacitors to start and run. I read somewhere that the 2 hp i have has 3x surge vs run. I believe it was 3300

[Mike90250]

I have an energy star front load washer (samsung), and it runs the drum about 4 revs each direction. When it reverses, I can hear the inverter grunt as the motor sucks juice. So mine has lots of peak loads - about every 90 sec as it reverses.

[Paul Land]

I'm not sure how much a energy star uses. On mine wash time on heavy was 31 mins. it used 220 whrs 783 watts spinning My 2000 surge 1700 generator runs it with no problem. And its not an inverter type .I've read about washers that take 2200 surge watts starting spin cycle with heavy wet clothes.Thats 183 amps on 12 volt wow.Not really doable . Ive also read about dc soft start motors In new washers. But my guess the washer.would be out of my budget. At $2 a gal i may just keep using the jenny for 30 mins .At 25 cents a load I'd have to wash a lot of clothes to justify the cost of the inverter.

If your tech inclined you can add a start capacitor to wash motor and it will push start it. ( cap provides needed surge)

[Ho jo]

I'm not sure how much a energy star uses. On mine wash time on heavy was 31 mins. it used 220 whrs 783 watts spinning My 2000 surge 1700 generator runs it with no problem. And its not an inverter type .I've read about washers that take 2200 surge watts starting spin cycle with heavy wet clothes.Thats 183 amps on 12 volt wow.Not really doable . Ive also read about dc soft start motors In new washers. But my guess the washer.would be out of my budget. At $2 a gal i may just keep using the jenny for 30 mins .At 25 cents a load I'd have to wash a lot of clothes to justify the cost of the inverter.