Napa 85-5000 battery charger manual

I'm with MEX, keep the batteries you have wired the way they are and ADD solar. Your issue isn't having enough battery but keeping them charged up. 200+W will do the job with good sun between visits. 235W panel is $210 each in some places and the 24V 20 amp controller will run $85. There are cheaper controllers on ebay if you want to save some bucks there.

Hi SkiMore,

Ah, but...after 85% state of charge acceptance rate drops to about 12.5 amps per 100 amp-hours of storage (at 12 volts). Thus generator run time becomes excessive. At 95% it is about 3 amps per 100 amp-hours.

There are 120 volt led bulbs but I'm not sure if they like inverters. What inverter do you have?

Unfortunately if you wish the battery bank to last, of the 5500 watts only 2750 should be used (i.e. 50%).

You speak of eight batteries. What are they? How many amp-hours?

SkiMore wrote:
When you suggested LED lights I thought you meant 120V LED bulbs. I think I'd need to run new wiring to use 12-30V LED bulbs. Maybe I'm lucky and the lights were on a separate circuit from the outlets. Can I run 12V on regular house wires assuming I pop them out of that panel? This sounds like a project for 2016.

The only reason I was considering dropping to 12V was so that my charger could get 2 of my batteries charged quickly and if I ran out of power I could repeat the process. Not elegant, but nothing to buy. Now that I found out I would need a new inverter the idea is less interesting

Last month I connected a kill-o-watt to a 5000BTU window AC unit and if I remember correctly peak draw was something like 400 watts with the compressor running and a lot less with just the fan. If I had a battery setup with 5568 watts I could probably run that AC for most of the weekend and still make coffee.

pianotuna wrote:
Hi skimore,

I would keep the batteries you have and see if they will meet your needs. Solar has a way of recovering batteries if there is a good temperature compensated charge controller.

Good to know. When I'm ready to do the install I'll ask the forum for controller recommendations.

pianotuna wrote:

I would start with a minimum of 60 watts per 1000 watts of storage. That would, in your case, be about 300 watts.

Since you are set up to do 24 volts I see NO advantages of down grading to 12 volts. LED's that will tolerate from 12 to 30 volts are readily available. One nice advantage is that you can use an inexpensive pwm controller (but one with temperature compensation please) to charge the battery bank.

I suspect with 232 amp-hours @ 24 volts (5568 watts) that you would have ample power for a weekend--and when you return for the next visit, the battery bank will be bursting full.

I'll go out on a limb and say you won't need to run the generator at all--and will be able to make that coffee electrically.

IMHO = in my humble opinion. (I almost always agree with Mex btw)

When you suggested LED lights I thought you meant 120V LED bulbs. I think I'd need to run new wiring to use 12-30V LED bulbs. Maybe I'm lucky and the lights were on a separate circuit from the outlets. Can I run 12V on regular house wires assuming I pop them out of that panel? This sounds like a project for 2016.

The only reason I was considering dropping to 12V was so that my charger could get 2 of my batteries charged quickly and if I ran out of power I could repeat the process. Not elegant, but nothing to buy. Now that I found out I would need a new inverter the idea is less interesting


Last month I connected a kill-o-watt to a 5000BTU window AC unit and if I remember correctly peak draw was something like 400 watts with the compressor running and a lot less with just the fan. If I had a battery setup with 5568 watts I could probably run that AC for most of the weekend and still make coffee.

full_mosey wrote:


MWO is Microwave Oven. Sorry.

This forum is so full of abbreviations there is no way to know them all. Someone should write a glossary sticky post.

full_mosey wrote:

I did make a mistake on the adding 1 12V to get 300AH. That would yield 36V in series.

I wasn't sure if that was a mistake or some wacky parallel + series method to get me more AH, but I got the idea.

full_mosey wrote:

...
X2 on solar. I run two 12V banks and both depend on solar with a genny for catchup bulk charging. It is too expensive to run a genny to get the bank fully charged. Bulk charging by genny can get you to 90% in about 3hrs, but it can take much longer to get that 10% while your genny slurps fuel. Solar is a one-time expense. Details of my system are in my profile.

HTH;
John

Yes, Running the genny to charge our system is too expensive in terms of gas, time, noise and generator hours. Over the last day I've come to realize that we probably have never fully charged it and this explains why it has never worked very well.

I was considering dropping down to a 12V(2x6V) system because of the expense of charging 8 batteries with our setup. It would charge fairly quickly.

SkiMore wrote:

What does MWO stand for?

Thank for the battery info. Glad to hear there are AGM options that won't break my back.

Project (1)
Is there any point trying to charge 4 GCs or 2 12V 100AH AGMs with my 24V 30A charger? I'm not interested in running the big generator for 4+ hours every time I use the cabin. Would it make more sense to get a 12V inverter and switch to a 12V system.

I'd like to see if I can get 2 or 4 of my current batteries to work well with my current charger in the short term. If they work well keep them for awhile, otherwise I'll replace them with a new batteries.

Project (2)
Add a solar panel and reduce generator use.


Or, maybe follow MEXICOWANDERER's advice and get a basic solar panel setup and follow up with batteries if necessary.

MWO is Microwave Oven. Sorry.

I did make a mistake on the adding 1 12V to get 300AH. That would yield 36V in series. Sorry. The point I was trying to make is that you are not stuck with 220AH/130lb increments with 12V AGMs because AGMs come in a variety of AH sizes. E.g., 4 x 80AHs AGMs could give 320AH. Here is a link to Deka with a list of AGM sizes.

On the 12V v.s. 24V issue, most people use 12V for smaller systems as in the RV or cabin. 24VDC and higher is usually a residential sized system where most uses of the battery is to produce AC, not DC. If you already have a 24V inverter, you will need to justify buying a 12V inverter. Or you could run two banks, one for 12VDC and another for inverter.

X2 on solar. I run two 12V banks and both depend on solar with a genny for catchup bulk charging. It is too expensive to run a genny to get the bank fully charged. Bulk charging by genny can get you to 90% in about 3hrs, but it can take much longer to get that 10% while your genny slurps fuel. Solar is a one-time expense. Details of my system are in my profile.

HTH;
John

SkiMore wrote:
What does MWO stand for?

I can't figure that one out either.

SkiMore wrote:
I thought I could easily switch to a 12V system, but I just checked the specs of my inverter and it is 24V input only. So I need to stick with 24V or get a new inverter.

Yes, stick with 24v if you can. If you change to 12v then the wiring has to get bigger to avoid voltage sags. I love my 24v system.. it's much 'snappier' than 12.

Hi skimore,

I would keep the batteries you have and see if they will meet your needs. Solar has a way of recovering batteries if there is a good temperature compensated charge controller.

I would start with a minimum of 60 watts per 1000 watts of storage. That would, in your case, be about 300 watts.

Since you are set up to do 24 volts I see NO advantages of down grading to 12 volts. LED's that will tolerate from 12 to 30 volts are readily available. One nice advantage is that you can use an inexpensive pwm controller (but one with temperature compensation please) to charge the battery bank.

I suspect with 232 amp-hours @ 24 volts (5568 watts) that you would have ample power for a weekend--and when you return for the next visit, the battery bank will be bursting full.

I'll go out on a limb and say you won't need to run the generator at all--and will be able to make that coffee electrically.

IMHO = in my humble opinion. (I almost always agree with Mex btw)

pianotuna wrote:
Hi SkiMore,

No I mean individual 2 volt cells. These can have a 20 year life span.

2 volt cells

EEK. That is an entirely different price point than I was thinking of. This is a low use weekend cabin. I don't need that much power.

Thanks for sending the link. I had never heard of them before. The 20 year life span is very impressive. Something to consider when I decide to pack it in and move to the cabin fulltime.

Thanks for all of the advice. The internet is full of smart helpful people.

What does MWO stand for?

I'd like to spend smart. The initial setup at the cabin wasn't the best way to spend money. Having 8 batteries that we can't charge properly was a bit of a waste.

Thank for the battery info. Glad to hear there are AGM options that won't break my back.

Project (1)
Is there any point trying to charge 4 GCs or 2 12V 100AH AGMs with my 24V 30A charger? I'm not interested in running the big generator for 4+ hours every time I use the cabin. Would it make more sense to get a 12V inverter and switch to a 12V system.

I'd like to see if I can get 2 or 4 of my current batteries to work well with my current charger in the short term. If they work well keep them for awhile, otherwise I'll replace them with a new batteries.

Project (2)
Add a solar panel and reduce generator use.


Or, maybe follow MEXICOWANDERER's advice and get a basic solar panel setup and follow up with batteries if necessary.

Hi SkiMore,

No I mean individual 2 volt cells. These can have a 20 year life span.

2 volt cells

SkiMore wrote:

pianotuna wrote:
Hi,

I'd prefer to see you go to six two volt cells rather than six volt jars. I'd look seriously at agm chemistry for the bank.

When you say "six two volt cells" do you mean 12V batteries? How is that batter than a pair of 6V ("three two volt cells")?

I think he wants to do this for as little as possible. My opinion is to get a solar panel and controller FIRST. This way you can leave the cabin with partially charged batteries and return and they will be full. By far the most cost effective correction. I would ask forum members for their opinion of an adequate 10 ampere 34 volt Open Circuit Voltage panel and an INEXPENSIVE PWM controller.

When you are THERE the panel will slow down the battery discharge a lot to boot. This will reduce generator run time.

Panel FIRST. Keep ALL the batteries. IMHO.