AIMS AC-DC Converter Battery Chargers

[tglozano]

with grid power, the description says I can recharge a lithium battery to 90% in an hour. I don't get many hours of sun. I want to use an AIM charger with a solar setup, to charge in an hour, but don't know how many panels of 400 watts I would need. I live near San Francisco, CA, we're expecting a big one in the near future, I would like to have something ready. Any suggestions will be appreciated. Thanks.

 

[kenryan]

To solve that puzzle, one would need to know how many amp hours your battery is, how many amps your charger puts out, and the efficiency of the charger. With that information one could determine how many watts of solar would be required.

 

[fratermus]

Some thoughts:

• charging from empty to full in 1 hour (1C charging) is hard on lithium. A more common maximum is half charged in an hour (ie, 50a max charging for 100Ah of lithium) and many people prefer even slower rates for longevity
• lithium doesn't really make a great standby chemistry as they don't like being stored at 100% SoC. AGM would be a better fit here IMO as it floats at 100% SoC and can take a lot of current in Bulk.
• I don't think this thread is about AIMs converters
• SF gets more hours of Full Sun Equivalent than one might think
• solar is a "low and slow" charging source. Trying to force it into "hard and fast" will be $$$
• it is impossible to answer "how many panels" without knowing the size of the lithium bank

Overall I suspect it'd be cheaper/easier to to use a generator for this scenario. $1000 will buy a nice inverter genny.

 

[anadiner]

with grid power, the description says I can recharge a lithium battery to 90% in an hour. I don't get many hours of sun. I want to use an AIM charger with a solar setup, to charge in an hour, but don't know how many panels of 400 watts I would need. I live near San Francisco, CA, we're expecting a big one in the near future, I would like to have something ready. Any suggestions will be appreciated. Thanks.

Personally, Im doing 400w per battery. Its an overshoot but Im complete off-grid so dont want be in middle of washing clothes to crap nothing.

Im in sunny state NC BUT the angle is super tough to get right. Btw, I havr bunch family all over CA. Familiar with the sunny weather. Btw been rumor if 'the big one' since I was a kid 50yrs ago.

Oh yea, ur lucky being grid-tie cuz AIMS has huge UL Listed 458 inverters. Off-grid is UL1741 which is like pulling teeth to find.

 

[anadiner]

Personally, Im doing 400w per battery. Its an overshoot but Im complete off-grid so dont want be in middle of washing clothes to crap nothing.

Im in sunny state NC BUT the angle is super tough to get right. Btw, I havr bunch family all over CA. Familiar with the sunny weather. Btw been rumor if 'the big one' since I was a kid 50yrs ago.

Oh yea, ur lucky being grid-tie cuz AIMS has huge UL Listed 458 inverters. Off-grid is UL1741 which is like pulling teeth to find.

I meant to say 'huge list if UL Listed 458 inverters'.

 

[anadiner]

Geez I cant hit these phone letters 'huge list of UL listed...' OMG LOL

 

[tglozano]

Some thoughts:

• charging from empty to full in 1 hour (1C charging) is hard on lithium. A more common maximum is half charged in an hour (ie, 50a max charging for 100Ah of lithium) and many people prefer even slower rates for longevity
• lithium doesn't really make a great standby chemistry as they don't like being stored at 100% SoC. AGM would be a better fit here IMO as it floats at 100% SoC and can take a lot of current in Bulk.
• I don't think this thread is about AIMs converters
• SF gets more hours of Full Sun Equivalent than one might think
• solar is a "low and slow" charging source. Trying to force it into "hard and fast" will be $$$
• it is impossible to answer "how many panels" without knowing the size of the lithium bank

Overall I suspect it'd be cheaper/easier to to use a generator for this scenario. $1000 will buy a nice inverter genny.

thank you for your thoughts. to quote Mark Twain "The coldest winter I ever spent was a summer in San Francisco." We get a lot of high and low fog. The sun may come out in the afternoon, plus now we have several days of smoke.

 

[fratermus]

The coldest winter I ever spent was a summer in San Francisco

Perhaps counterintuitively, panels make more power when they are cooler.

We get a lot of high and low fog. The sun may come out in the afternoon

FSE averages are typically based on 30yr aggregations of irradiance observations at a given location. Climate weather patterns, elevation, etc are baked into the historical observations since the pyrometers can only measure the sunlight that reaches them. We can use FSE averages to do system-planning math or use a tool like PVWATTS that does it for us. Or we can guess and hope for the best.

Smoke, OTOH, is a transient effect and not a useful factor for solar sizing IMO. During the Oregon wildfires last year I was seeing 9w out of a 570w array at solar noon. There is no practical way to size a solar array for that kind of degradation.