Inexpensive Battery Any Good?

[Humblebumble7]

Looking at a Haya 12 volt 100 AH LIPO4 battery on Amazon that says it has a 100 amp BMS. Does anyone have experience using this brand? Price is great at $260, but I don’t want it to die when I need it during a power outage.

Thanks!

 

[Ampster]

With Amazon, returns are free so buy it and test it? If it does not have 100 Ahrs capacity then return it.

 

[Texas-Mark]

With Amazon, returns are free so buy it and test it? If it does not have 100 Ahrs capacity then return it.

Not with every Amazon item.. One must look at the return policy and if it was shipped and sold by Amazon. This item is sold by a third party. Sure they except returns but it does not say free returns. One should check with the seller first.

Ships from
SZJTech
Sold by
SZJTech
Returns
Eligible for Return, Refund or Replacement within 30 days of receipt

 

[Humblebumble7]

Thanks for the advice! I’ll check the return policy because I want to try it out.

 

[Humblebumble7]

Finally got my first battery system completed. Connected a 100 AH Dee Spaek battery to a 1,000 watt pure sine wave inverter. Battery came with a lithium battery charger, but also connected a 60 amp/50 volt PWM solar charge controller that can accommodate up to 780 watts of PV. Fused battery with 100 amp fuse and red lead on PV input is also fused. Added a battery shunt to monitor state of charge and power consumption.

 

[JRH]

Not with every Amazon item.. One must look at the return policy and if it was shipped and sold by Amazon. This item is sold by a third party. Sure they except returns but it does not say free returns. One should check with the seller first.

Ships from
SZJTech
Sold by
SZJTech
Returns
Eligible for Return, Refund or Replacement within 30 days of receipt

I won’t buy much from Amazon unless it is either SOLD by Amazon or SHIPPED By Amazon OR BOTH under the Prime plan…the third party sellers can ignore you if need be..
there is no return guarentee in most cases… check before you dive in…

 

[meetyg]

Finally got my first battery system completed. Connected a 100 AH Dee Spaek battery to a 1,000 watt pure sine wave inverter. Battery came with a lithium battery charger, but also connected a 60 amp/50 volt PWM solar charge controller that can accommodate up to 780 watts of PV. Fused battery with 100 amp fuse and red lead on PV input is also fused. Added a battery shunt to monitor state of charge and power consumption.

You really shouldn't use a PWM controller with a Lithium battery. It could cause the BMS to trip, or worse, damage the cells.
Basically what these PWM controllers do is connect the solar panel directly to the battery for very short pulses (hence the P in PWM). This means that the BMS could see a high voltage and trip, if it's fast enough to identify it. Otherwise, the BMS might not protect properly and you will cook your cells.
Besides, PWM SCCs are much less efficient than MPPT ones, so you aren't getting maximum efficiency from your solar.

 

[fafrd]

You really shouldn't use a PWM controller with a Lithium battery. It could cause the BMS to trip, or worse, damage the cells.
Basically what these PWM controllers do is connect the solar panel directly to the battery for very short pulses (hence the P in PWM). This means that the BMS could see a high voltage and trip, if it's fast enough to identify it. Otherwise, the BMS might not protect properly and you will cook your cells.
Besides, PWM SCCs are much less efficient than MPPT ones, so you aren't getting maximum efficiency from your solar.

Please don’t fear monger.

A PWM SCC cannot ‘cook’ a LiFePO4 battery.

It will not be as efficient as an MPPT SCC but when Vmp of the solar panels is close to Vbat, the loss in is minor.

Will has done great videos comparing PWM and MPPT SCC charging LiFePO4 batteries and the results shocked even him.

PWM SCCs are perfectly safe charging LiFePO bateries.

 

[Humblebumble7]

You really shouldn't use a PWM controller with a Lithium battery. It could cause the BMS to trip, or worse, damage the cells.
Basically what these PWM controllers do is connect the solar panel directly to the battery for very short pulses (hence the P in PWM). This means that the BMS could see a high voltage and trip, if it's fast enough to identify it. Otherwise, the BMS might not protect properly and you will cook your cells.
Besides, PWM SCCs are much less efficient than MPPT ones, so you aren't getting maximum efficiency from your solar.

Appreciate your input and knowledge. I will upgrade to MPPT when I get another battery installed, but Will and others have demonstrated PWM systems that operate safely so I don’t think I need to spend the money quite yet.

 

[Humblebumble7]

Please don’t fear monger.

A PWM SCC cannot ‘cook’ a LiFePO4 battery.

It will not be as efficient as an MPPT SCC but when Vmp of the solar panels is close to Vbat, the loss in is minor.

Will has done great videos comparing PWM and MPPT SCC charging LiFePO4 batteries and the results shocked even him.

PWM SCCs are perfectly safe charging LiFePO bateries.

Thank you for easing my mind! My system isn’t perfect by any stretch but it is only going to power essential things (furnace for a few hours in winter or refrigerator in summer). Solar panels are in basement next to milk crate and will be drug outside when needed. I’ll use the battery charger to keep it powered up.

 

[Texas-Mark]

You really shouldn't use a PWM controller with a Lithium battery. It could cause the BMS to trip, or worse, damage the cells.
.....
Besides, PWM SCCs are much less efficient than MPPT ones, so you aren't getting maximum efficiency from your solar.

Been using PWM for years with lifepo4 with zero issues.
And they are not that much less efficient.

 

[meetyg]

PWMs do not do constant current / constant voltage charging, as needed by Lithium batteries. They give short pulses of PV panel voltage. I guess it depends on the frequency of the PWM, reaction time of the BMS and PV voltage.
For those using PWM with Lithium, you are just lucky... The fact that it works doesn't mean that it works like it should.

Efficiency differences may depend on PV voltage. I guess that if your PV voltage is in the ballpark of the battery voltage (e.g. 18v panel with a 12v battery) then you won't see much difference. But when you have higher PV voltages, the difference is apparent.
Many comparisons have been done, showing the efficiency difference. I'm not going to argue...

 

[Texas-Mark]

For those using PWM with Lithium, you are just lucky... The fact that it works doesn't mean that it works like it should.

Not lucky at all, it works just fine. Not sure what you mean about not being able to do constant current. Mine will do their rated current just fine. As the batteries gets charged, current tapers off just like with my MPPT controller (on a different system).

One thing I see here often is theory vs real life. I've been doing solar for well over 20 years, and have more of the latter under my belt.

 

[fafrd]

PWMs do not do constant current / constant voltage charging, as needed by Lithium batteries. They give short pulses of PV panel voltage. [/u]I guess it depends on the frequency of the PWM[/b], reaction time of the BMS and PV voltage.

Why don’t you have a look at the frequencies typically involved and get back to us once you have educated yourself.

Oh, and you cannot ‘pulse’ voltage into a battery. What you can do is ‘pulse’ current into a battery (or more correctly in the case of PWM SCCs, discharge charge into a battery from a charged capacitor).

For those using PWM with Lithium, you are just lucky... The fact that it works doesn't mean that it works like it should.

More fear-mongering. Please take it elsewhere (meaning away from DIY Solar Forum).

Efficiency differences may depend on PV voltage. I guess that if your PV voltage is in the ballpark of the battery voltage (e.g. 18v panel with a 12v battery) then you won't see much difference. But when you have higher PV voltages, the difference is apparent.

Yes, the further battery voltage is below Vmp of the solar string, the more efficiency of PWM will underperform that of MPPT.

So trying to charge a 12V battery with a 100V solar string may not be the wisest idea.

But it is perfectly safe and there is no ‘luck’ involved.

For those like me charging 8S LiFePO4 with 30-35V strings, the efficiency loss versus MPPT can be surprisingly modest (as Will has proven).

Many comparisons have been done, showing the efficiency difference. I'm not going to argue...

No one is arguing with you about the fact that PWM SCCs are less efficient than MPPT SCCs. It’s your suggestion that PWM is somehow less ‘safe’ than MPPT and that if it’s working for anyone it is only due to blind luck which is wrong (and unacceptable to spread on this Forum as though you know what you are talking about).

Any repeat of any of that nonsense/misinformation and I’ll be reporting you to Will…

 

[Ampster]

PWMs do not do constant current / constant voltage charging, as needed by Lithium batteries.

Perhaps it depends on how long the pulse is? Most solar charge controllers do not do true constant current charging either because as solar generaton varies, the current will vary. There is no magic to CC/CV charging. Any Power supply which can control current and voltage natively does CC/CV charging. I agree with @fafrd , that you are fear mongering without explaining your concerns in the context of the physics of charging. For example, when a battery sees a voltage at the interface of the source and the battery, the voltage will be the battery voltage of the battery subject to any increase caused by the current of the source. Therefore it is not likely that a PWM charge source would cause a BMS to trip. 750 Watts at 50 volts is only 15 Amps which is small compared to the 100 Ahr battery.

 

[meetyg]

I'm not fear mongering. I love this forum and respect its members. I am/was just trying to help.
I'm talking from knowledge and experience.
I have had some lithium battery BMSs go crazy when charged with a few different PWM SCC.
I guess maybe the cheap ones are more problematic. Maybe newer ones from reputable vendors are designed better to handle lithium? IDK.

I don't think I'm the only one who thinks PWM isn't good for lithium (especially a fully charged battery).
Here are a few sources. You can choose to rely on them or not. It's your choice.
Again, it might be product dependent, but in general what I know and have experienced is that PWM and Lithium (with BMS) don't go well together.

Do not use PWM solar charge controller to your Lithium Battery

Do not use PWM solar charge controller to your Lithium Battery www.popsail.com

m.popsail.com

Is it possible to charge Li-ion battery system using BlueSolar PWM charge controller ? - Victron Community

community.victronenergy.com

Running a lithium charger and solar panel through a PWM charge controller??

Hi, I'm building a solar generator and I'm at the point of "charging" the box (generator). My plan was to use an ASE port on the box going straight into the PWM charge controller, and run an adapter cable MC4 (solar panel) to ASE (plug into the box). My question, I have a lithium charger (AC...

diysolarforum.com

So as you can see there isn't really a consensus on whether it's OK to use PWM with Lithium or not.
So I guess the definitive answer is that it depends.
What most of these PWM SCCs rely on is that when panel voltage is connected to a battery source, the voltage will drop to the battery voltage, because the battery is sinking current. But, what happens when the battery is at a high SOC ? It will sink less and less current (look at Lifepo4 voltage curve graph). The PWM SCC will try to switch faster, so that the battery won't "see" a higher voltage, but it's switching ability is limited (by PWM frequency, components used, etc...). So at high SOC the BMS might see a higher voltage pulse. It depends on the BMS settings and capabilities to properly handle this (cutting off charge MOSFET). I guess that if you don't charge to maximum pack voltage with a PWM SCC, maybe this is a non-issue. Please understand that with PWM there is no real "stepping down" of voltage, it relies on the battery to bring the voltage down. This works a bit differently with buck converters, that use a coil/inductor that step down the voltage. That's why you can tell if an SCC is really PWM/MPPT or not: if it doesn’t have coils/inductors (of a noticeable size) it's not an MPPT.

But I accept your corrections: Maybe I shouldn't have have been definitive about PWM as a whole. I should have stated that the OP made sure his PWM is intended for Lithium with a proper charging profile (CC/CV). I guess I was distracted by the cheap looking PWM the OP was using (especially with the fake "MPPT" writing on it).

These cheapies don't have proper charging algorithms for Lithium (even if they support Lithium voltages). I guess thier PWM frequency is also pretty low compared to the brand name ones, so that could be problematic for the BMS as it could see a higher voltage than allowed.
So I meant "don't use THAT PWM SCC".
I guess maybe the brand name PWMs have a fancier control algorithm (which requires more expensive components) that eliminates/minimizes the issue stated above.
So my apologies to the OP and to the forum.

P.S. On a personal note: I think I have the right to share my experience, knowledge and opinions on this forum just like anybody else.
If I state something wrong, then I'd love to be corrected. I'm here to learn. But please don't accuse me of fear mongering or anything like that.

 

[Tomthumb62]

I'm not fear mongering. I love this forum and respect its members. I am/was just trying to help.
I'm talking from knowledge and experience.
I have had some lithium battery BMSs go crazy when charged with a few different PWM SCC.
I guess maybe the cheap ones are more problematic. Maybe newer ones from reputable vendors are designed better to handle lithium? IDK.

I don't think I'm the only one who thinks PWM isn't good for lithium (especially a fully charged battery).
Here are a few sources. You can choose to rely on them or not. It's your choice.
Again, it might be product dependent, but in general what I know and have experienced is that PWM and Lithium (with BMS) don't go well together.

Do not use PWM solar charge controller to your Lithium Battery

Do not use PWM solar charge controller to your Lithium Battery www.popsail.com

m.popsail.com

Is it possible to charge Li-ion battery system using BlueSolar PWM charge controller ? - Victron Community

community.victronenergy.com

Running a lithium charger and solar panel through a PWM charge controller??

Hi, I'm building a solar generator and I'm at the point of "charging" the box (generator). My plan was to use an ASE port on the box going straight into the PWM charge controller, and run an adapter cable MC4 (solar panel) to ASE (plug into the box). My question, I have a lithium charger (AC...

diysolarforum.com

So as you can see there isn't really a consensus on whether it's OK to use PWM with Lithium or not.
So I guess the definitive answer is that it depends.

But I accept your corrections: Maybe I shouldn't have have been definitive about PWM as a whole. I should have stated that the OP made sure his PWM is intended for Lithium with a proper charging profile (CC/CV). I guess I was distracted by the cheap looking PWM the OP was using (especially with the fake "MPPT" writing on it).

These cheapies don't have proper charging algorithms for Lithium (even if they support Lithium voltages). I guess thier PWM frequency is also pretty low compared to the brand name ones, so that could be problematic for the BMS as it could see a higher voltage than allowed.
So I meant "don't use THAT PWM SCC".

So my apologies to the OP and to the forum.

P.S. On a personal note: I think I have the right to share my experience, knowledge and opinions on this forum just like anybody else.
If I state something wrong, then I'd love to be corrected. I'm here to learn. But please don't accuse me of fear mongering or anything like that.

That’s one of the more informed and honest corrections I’ve seen on any type of forum.

 

[fafrd]

I'm not fear mongering. I love this forum and respect its members. I am/was just trying to help.
I'm talking from knowledge and experience.
I have had some lithium battery BMSs go crazy when charged with a few different PWM SCC.
I guess maybe the cheap ones are more problematic. Maybe newer ones from reputable vendors are designed better to handle lithium? IDK.

I don't think I'm the only one who thinks PWM isn't good for lithium (especially a fully charged battery).
Here are a few sources. You can choose to rely on them or not. It's your choice.
Again, it might be product dependent, but in general what I know and have experienced is that PWM and Lithium (with BMS) don't go well together.

Do not use PWM solar charge controller to your Lithium Battery

Do not use PWM solar charge controller to your Lithium Battery www.popsail.com

m.popsail.com

Is it possible to charge Li-ion battery system using BlueSolar PWM charge controller ? - Victron Community

community.victronenergy.com

Running a lithium charger and solar panel through a PWM charge controller??

Hi, I'm building a solar generator and I'm at the point of "charging" the box (generator). My plan was to use an ASE port on the box going straight into the PWM charge controller, and run an adapter cable MC4 (solar panel) to ASE (plug into the box). My question, I have a lithium charger (AC...

diysolarforum.com

So as you can see there isn't really a consensus on whether it's OK to use PWM with Lithium or not.
So I guess the definitive answer is that it depends.

But I accept your corrections: Maybe I shouldn't have have been definitive about PWM as a whole. I should have stated that the OP made sure his PWM is intended for Lithium with a proper charging profile (CC/CV). I guess I was distracted by the cheap looking PWM the OP was using (especially with the fake "MPPT" writing on it).

These cheapies don't have proper charging algorithms for Lithium (even if they support Lithium voltages). I guess thier PWM frequency is also pretty low compared to the brand name ones, so that could be problematic for the BMS as it could see a higher voltage than allowed.
So I meant "don't use THAT PWM SCC".

So my apologies to the OP and to the forum.

P.S. On a personal note: I think I have the right to share my experience, knowledge and opinions on this forum just like anybody else.
If I state something wrong, then I'd love to be corrected. I'm here to learn. But please don't accuse me of fear mongering or anything like that.

This is a very balanced and helpful post. If you’d led with this you’d likely have been the hero of the thread.

‘Make sure that if you use a cheap PWM SCC to charge a LiFePO4 battery that it is truly designed to charge LiFePO4 batteries’ is helpful advice that no one here would have questioned.

And after all of this context, I trust your opinion more than mine as to whether the PWM SCC selected by the OP is one he should be worried about using to charge a LiFePO4 battery or not.

The ‘fear mongering’ I objected to was your statements suggesting PWM SCCs cannot be designed to safely charge LiFePO4 batteries.

Bad product design abounds and Forums like this are the best way for concerned enthusiasts to avoid poorly-designed products.

But suggesting that there is a fundamental incompatibility and that even properly-designed products can cause damage to the battery is a different matter entirely…

 

[fafrd]

That’s one of the more informed and honest corrections I’ve seen on any type of forum.

Absolutely agree.

 

[Ampster]

I guess that if you don't charge to maximum pack voltage with a PWM SCC, maybe this is a non-issue.

I think that is a good conclusion. I personally would not use a PWM charge controller any way, because I want better control over the charging process.