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Can my solar controller kill my AC plug in charger?

Stewfish

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Oct 20, 2020
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368
Does anyone know much about charging batteries with an AC battery charger?

I'm wondering why my AC to DC chargers are dying after about 24hrs? It doesn't make sense.

All I can think of:
I'm wondering if I run my off grid generator on a cloudy day - can the sun poking out randomly and charging at say 57 volts vs the 55 volts from an AIMS plugin AC to DC charger will it back feed the extra 2 volts higher into the aims charger? Even on a cloudy day but brighter I have seen up to 1000w being made by the 24 solar panels and like 50 watts on a dark grey day.

Details:
I run my genny after a few days of no sun to charge up my 48v batteries. The batteries are 28kwh so it will never get the battery topped up or even past 50% that I have seen. I assume the charger is bulk charging the whole time since I never see it get above 54v while 58v is full. In the past two years my generator shows 380 hours all charging the batteries on cloudy weeks. 380hrs÷ 8 hr run time = 47.5 tanks of gas ÷2 years = 24 tanks of gas a winter. I have to charge sometimes once in the day and the night, but mostly just charging at night. My genny is a Yamaha inverter gen and the power meter shows it only 4 out of 5 bars to run the AIMS charger and not popping the gen breaker or showing an over power error.

If my theory is correct I worry about buying say a 48v golf cart charger even if it's lifepo capable and I will now be on my 3rd AIMS charger in as many years with only 190hrs average each charger.

Most chargers seem to be 55v max vs 58v lifepo max.

Does anyone have a lot of experience with charging via your gen?

Thanks!
 
My guess would be a wiring issue is causing the damage to the chargers.
Usually this will be a grounding issue. Either Something that should be grounded, isn't. Or something that shouldn't be grounded, is.
A lot of times it's the mistake of connecting the battery negative to the grounding system.
 
So this one?
If your batteries aren't going open-circuit from BMS protections, then adding more current from an SCC isn't going to bounce the voltage high enough to blow up a charger that has OVP, though I suppose it might depend on the details of the OVP (if it's a crowbar it might blow a fuse, for instance...) and the total current and your BMS allowable charge current...

Edit: If you tell us more (mfr and model of the panels, SCC, AC charger, inverter, wiring, etc) and even post pictures, we can help better.
 
Just a guess because I am unfamiliar with your charger. If it is a type that automatically detects battery voltage for setting charging it may be that sudden changes (such as a BMS trip) can cause a failure due to SCC voltage going high. Typically it is no problem to use both SCC and a battery charger at the same time. But all my uses of this have been with battery chargers that are only have the one correct battery voltage.
 
If the higher voltage from a solar charge controller could kill converters that use lower charge voltages then I think we would see a ton of complaints from the RV community.

At suggested above, the BMS going into protection mode due to high voltage of the battery or a cell could be the culprit. What are the OVP settings on the BMS?
 
My guess would be a wiring issue is causing the damage to the chargers.
Usually this will be a grounding issue. Either Something that should be grounded, isn't. Or something that shouldn't be grounded, is.
A lot of times it's the mistake of connecting the battery negative to the grounding system.
I think they are just junk and won't last past 200 hours. Batteries aren't grounded in the US
 
So this one?
If your batteries aren't going open-circuit from BMS protections, then adding more current from an SCC isn't going to bounce the voltage high enough to blow up a charger that has OVP, though I suppose it might depend on the details of the OVP (if it's a crowbar it might blow a fuse, for instance...) and the total current and your BMS allowable charge current...

Edit: If you tell us more (mfr and model of the panels, SCC, AC charger, inverter, wiring, etc) and even post pictures, we can help better.
There are no wiring issues after 4 years running the same way, but thanks. I think the chargers are just junk
 
Just a guess because I am unfamiliar with your charger. If it is a type that automatically detects battery voltage for setting charging it may be that sudden changes (such as a BMS trip) can cause a failure due to SCC voltage going high. Typically it is no problem to use both SCC and a battery charger at the same time. But all my uses of this have been with battery chargers that are only have the one correct battery voltage.
No issues with the BMS or battery. I just noticed the charger wasn't charging and dead again using a yamaha inverter generator.

It's clean gen power going to the aims charger to a 48v 28kwh 16s lifepo battery to the 6000w mpp all in one to the house
 
If the higher voltage from a solar charge controller could kill converters that use lower charge voltages then I think we would see a ton of complaints from the RV community.

At suggested above, the BMS going into protection mode due to high voltage of the battery or a cell could be the culprit. What are the OVP settings on the BMS?
It was just a theory I had. I had no issues with the system I just noticed (via the shunt) after charging a few hours the other day it wasn't charging the battery any longer.

I have read in this forum many negative comments about the aims 48v charger. I thinks its just not a good charger.
 
I'm not sure how I feel about thier boost mode at 59.2v and normal at 54.4 when it gets too warm for example, vs normal 58.4v for lifepo. Also 18 amps vs 15amps would over tax my small yamaha and require me to use oir 3500w genny at 2 gallons per 8 hrs, vs a 15a charger at 1 gallon for 8 hours on my smaller Yamaha gen.
 
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Powermax voltage can be adjusted as a fixed power supply. Yes power factor is bad at probably 30% additional apparent power needed.

Or try Meanwell NPB-1200-48 for the same 18 amps but is power factor corrected so it should run fine on less than 1500 apparent watts. A few different charging profiles might have one you like.

https://trcelectronics.com/products/mean-well-npb-1200-48
 
That could be. I don't think it's considered a Tier 1 brand.

Powermax voltage can be adjusted as a fixed power supply. Yes power factor is bad at probably 30% additional apparent power needed.

Or try Meanwell NPB-1200-48 for the same 18 amps but is power factor corrected so it should run fine on less than 1500 apparent watts. A few different charging profiles might have one you like.

https://trcelectronics.com/products/mean-well-npb-1200-48
Cool, I will check them out.

I don''t charge my 28kwh battery until under like 52.3v encase the sun comes out the next day. so I def just need to high voltage 58.4v only really in either a 15ish or 30ish amps (my small vs medium genny). It would take more than a week of charging before it would get even close to getting fully charged w 15 amps, esp w a full time load as we are off grid.
 
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