How dangerous is to use an AGM deep cycle battery with a cheap pwm charge controller?

[wdc]

Hello, I use this charge controller (CC):
HS0055-228x228.png
Probably the most used CC in the world, and probably one of the worse also, because is the cheaper one, It's a 12/24V 20A pwm chinese CC, my question is: ist it worth to buy an agm deep cycle battery and use it with this CC?. Good CC are expensive and hard to find, lots of Mppt chinese CC are known to be pwm and not real mppt.

will this cheap CC indeed damage a typical agm battery? It doesn't have any agm specific profile to charge and I even don't trust these are real 3 steps CC.

thanks in advance.

[SunEagle]

Hello, I use this charge controller (CC):
HS0055-228x228.png
Probably the most used CC in the world, and probably one of the worse also, because is the cheaper one, It's a 12/24V 20A pwm chinese CC, my question is: ist it worth to buy an agm deep cycle battery and use it with this CC?. Good CC are expensive and hard to find, lots of Mppt chinese CC are known to be pwm and not real mppt.

will this cheap CC indeed damage a typical agm battery? It doesn't have any agm specific profile to charge and I even don't trust these are real 3 steps CC.

thanks in advance.

Well AGM batteries can usually handle a higher charge rate then a standard FLA type. But if you try to charge faster then C/7 you could cook the battery.

Since that CC is rated only 20A you could use a battery rated between 150Ah and 240Ah but that depends on if your panels can generate that 20 amps.

[wdc]

Thanks, my panels only can generate ~10,6 amps so I'm thinking about buying an 80 to 100Ah battery but I don't want to buy a better CC and also don't want to destroy an AGM battery so I'm undecided about wether to buy a "heavy duty" flooded lead one or an AGM battery. I have never own an AGM battery and I don't know if my current CC can handle it without damaging it.

[Mike90250]

An AGM battery has/requires different charge voltage than a flooded battery, so I expect an AGM battery may not last as long as the warranty,

[littleharbor]

That charge controller has adjustable charging set points. Be sure the set points don't exceed the battery's specs.

[wdc]

An AGM battery has/requires different charge voltage than a flooded battery, so I expect an AGM battery may not last as long as the warranty,

Yes, that's my biggest fear, to buy an AGM battery and that it last no more than a year or two. Thanks.

[wdc]

That charge controller has adjustable charging set points. Be sure the set points don't exceed the battery's specs.

Thanks, the only useful voltage setting that you can change in this CC is the max charging voltage, I could set this to 14,4V.........14,7V max as the majority of the AGM batteries ask but that probably only means bulk charging, this CC has no settings for absorb or float voltages, let alone temp compensation.

[wdc]

Well, this is what I'm going to do (as soon as I can), first I'll buy another panel to increase my current from 10,6A to 13,4A, then I'm going to buy the heaviest 100Ah FLA battery I could find. Thanks.

[littleharbor]

Thanks, the only useful voltage setting that you can change in this CC is the max charging voltage, I could set this to 14,4V.........14,7V max as the majority of the AGM batteries ask but that probably only means bulk charging, this CC has no settings for absorb or float voltages, let alone temp compensation.

The setpoint is where the controller transitions from Bulk to Absorb, Which is where the set voltage value will hold as the battery goes through absorb mode. Bulk is simply full throttle until the set voltage is met.

[wdc]

The setpoint is where the controller transitions from Bulk to Absorb, Which is where the set voltage value will hold as the battery goes through absorb mode. Bulk is simply full throttle until the set voltage is met.

thanks, I wish my CC could be programmable with bulk, absorb and float voltages but is not, the only voltage I can set is the maximum, which I assume is the bulk voltage.

[littleharbor]

As I said, That setting is the absorb voltage. Bulk is full throttle UP TO the absorb voltage hold point. I haven't messed with those CC's but I'm surprised it doesn't have a float setting. According to this info taken from a sellers site it DOES have adjustable settings.
[="bgcolor: #FFFFFF, colspan: 4"]14.4V(Sealed) 14.2V(Gel) 14.6V(Flood)[/TD]
[/TR]
[TR]
Float charge[/TD]
]13.7V(defaul,adjustable)[/TD]


*all red color voltage X2 ,while using 24V system.

[wdc]

that's the ONLY voltage adjustable, that 13,7V that they call "float charge", there's no other setting adjustable by the user, one can't set bulk nor absorb voltage.

as it turns out this cheap CC HAS a battery selector, b01 for SLA, b01 for Gel and b03 for FLA, I've always had it on b01 and I don't have a SLA battery, I have an FLA, so I should be using b03 instead. anyway, that setting only put a limit to the "equalization" voltage in the CC, 14,4 for SLA and 14,6 on FLA but who knows when the CC decides to "equalize" the battery. the information on this cheap CC is very lacking, to say the least.