Is battery equalizer required for batteries in series?
- Thread starter Riley
- Start date
WYtreasure
It's not happy hour, I'm just like this.
@rmaddy @time2roll @Bobert @timselectric
Thanks, I feel a little better. Perhaps by the time I am ready to upgrade to 48 volts, I should consider building my own battery. ?
Somewhere in the forum I saw the Mazava PLC-10, and have purchased 1 for $30 @ alibaba.
Apparently I will be purchasing a second Mazava balancer, as I will have my batteries 2S2P to attain 24V, and need 1 for each series.
After connecting 2 batteries in series to one balancer, and the other series to the second balancer; should I then connect the 2 balancers together? My guess is yes, and this would be my setup.
My 24V balancing act.
Do I understand correctly that Riley would (if he were using the Mazava) need 2 balancers as well?
And his would look like this:
Riley's balancing act if he were using the same balancer as me.
I have no idea how to make the connections using the PowMr unit.
Thanks, I feel a little better. Perhaps by the time I am ready to upgrade to 48 volts, I should consider building my own battery. ?
You're too quick for me, I see you already made a purchase.
Somewhere in the forum I saw the Mazava PLC-10, and have purchased 1 for $30 @ alibaba.
Mazava 12v 10a Battery Balancer Equalizer For 24v48v96v Gel Flood Agm Lead Acid Batteries Lithium Battery - Buy Battery Equalizer,Battery Balancer,Battery Equalizer Balancer Product on Alibaba.com
Mazava 12v 10a Battery Balancer Equalizer For 24v48v96v Gel Flood Agm Lead Acid Batteries Lithium Battery - Buy Battery Equalizer,Battery Balancer,Battery Equalizer Balancer Product on Alibaba.com
www.alibaba.com
Apparently I will be purchasing a second Mazava balancer, as I will have my batteries 2S2P to attain 24V, and need 1 for each series.
After connecting 2 batteries in series to one balancer, and the other series to the second balancer; should I then connect the 2 balancers together? My guess is yes, and this would be my setup.
My 24V balancing act.Do I understand correctly that Riley would (if he were using the Mazava) need 2 balancers as well?
And his would look like this:
Riley's balancing act if he were using the same balancer as me.I have no idea how to make the connections using the PowMr unit.
timselectric
If I can do it, you can do it.
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I would think that the balancer is available in a 4 battery version, too. But, maybe not.
WYtreasure
It's not happy hour, I'm just like this.
That makes me wonder about some in series and some in parallel causing an issue with a single balancer. Don't you wish I knew what I was talking about so I wouldn't get so far off track?
timselectric
If I can do it, you can do it.
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That's ok, I tend to stay way off track.
We can lean on each other. lol
wattmatters
Solar Wizard
It's just a rebranded HA02 balancer/equalizer available from various places. Google "HA02 equaliser".
The HC02 model is the same except it has a digital voltage display for each battery.
There are also HA12 models which have bluetooth/phone app I think.
They operates when there is a 10mV difference between batteries and it transfers energy between batteries. Works with 6-12V batteries from 2 to 4 batteries.
Based on testing today, I found that the battery was well balanced at rest (even a few minutes after MPPT charging stopped).
They are off when it's charging.
I measured two batteries out of four because the other two were too deep inside to reach.
(After the MPPT charge stopped for 3 minutes)
The Volt that is shown in Growatt is 55V.
Battery 1:13.36V
Battery 2:13.87V
(After the MPPT charge stopped for 5 seconds)
The Volt that is shown in Growatt: 56.7V (rapidly dropping)
Battery 1:13.41V
Battery 2:14.36V
It seems like some batteries are highly responsive to the charging current while other batteries are not.
Based on another measurement a few days ago after sunset, however, they are balanced at rest:
All 4 batteries: 13.25 13.25, 13.25, 13.24V
It shows that once the charging stops, the batteries will balance themselves.
I have tested limiting the charging current to 30A. It does not solve this issue. Instead, it stops charging at 55V.
If not, limit the charging current (set to 60A), which will allow it to push the voltage to the set bulk charging voltage of 57V and stop.
Is this something that a battery balancer should solve, or is it some faulty battery issue that I should talk with the seller about?
Update: Tested 3 batteries right after chargeing (Still didnt brother to reach the 4th battery in the deepest part):
13.25V 14.04V 14.04V
the one with the lower voltage are also connected to a 48-12 DC-DC charger, not sure if thats the reason.
They are off when it's charging.
I measured two batteries out of four because the other two were too deep inside to reach.
(After the MPPT charge stopped for 3 minutes)
The Volt that is shown in Growatt is 55V.
Battery 1:13.36V
Battery 2:13.87V
(After the MPPT charge stopped for 5 seconds)
The Volt that is shown in Growatt: 56.7V (rapidly dropping)
Battery 1:13.41V
Battery 2:14.36V
It seems like some batteries are highly responsive to the charging current while other batteries are not.
Based on another measurement a few days ago after sunset, however, they are balanced at rest:
All 4 batteries: 13.25 13.25, 13.25, 13.24V
It shows that once the charging stops, the batteries will balance themselves.
I have tested limiting the charging current to 30A. It does not solve this issue. Instead, it stops charging at 55V.
If not, limit the charging current (set to 60A), which will allow it to push the voltage to the set bulk charging voltage of 57V and stop.
Is this something that a battery balancer should solve, or is it some faulty battery issue that I should talk with the seller about?
Update: Tested 3 batteries right after chargeing (Still didnt brother to reach the 4th battery in the deepest part):
13.25V 14.04V 14.04V
the one with the lower voltage are also connected to a 48-12 DC-DC charger, not sure if thats the reason.
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Another measurement for all four batteries, about 3 minutes after charging, was:
13.33V, 14.00V, 14.00V, 14.12V
It seems like only the first one gets off-limits while changing, which excludes the possibility that it was caused by 48-12 DC-DC? Since both of my first and fourth batteries were wired with 48-12 DC-DC (positive and nagtive), only one of them has a significant problem.
13.33V, 14.00V, 14.00V, 14.12V
It seems like only the first one gets off-limits while changing, which excludes the possibility that it was caused by 48-12 DC-DC? Since both of my first and fourth batteries were wired with 48-12 DC-DC (positive and nagtive), only one of them has a significant problem.
Not really balancing to each other in series. The differential becomes larger at the top of charge. Once they fall back resting in the flat charge curve they will always come together.
WYtreasure
It's not happy hour, I'm just like this.
I don't think the OP does the "resting" thing.
timselectric
If I can do it, you can do it.
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Doesn't appear to be.
Most of you are wrong. Think about it, a lead acid happily floats at a wide range of voltages. If two are in series and one is full and the other 98% full, the full one will just create a bit of heat and stay full, allowing the 98% full one to slowly charge. So series floated lead acids will always equalise naturally. Provided you're not trying to fast charge them before you've let them settle, this is fine.
The only problem arises if you're in the habit of draining them quite low. If one battery has a slightly lower capacity (maybe it's older or wasn't made so well), when you discharge to what your system thinks is 20%, you've actually got one at 25% and one at 15%. The 15% one is aged by this stress, and is now even lower capacity. Next time the action of almost fully discharging will be worse - say 26% and 14%. And so on.
If in doubt just buy a balancer and leave it connected all the time.
The only problem arises if you're in the habit of draining them quite low. If one battery has a slightly lower capacity (maybe it's older or wasn't made so well), when you discharge to what your system thinks is 20%, you've actually got one at 25% and one at 15%. The 15% one is aged by this stress, and is now even lower capacity. Next time the action of almost fully discharging will be worse - say 26% and 14%. And so on.
If in doubt just buy a balancer and leave it connected all the time.
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Everyone would be wrong if the battery in this thread was lead acid. But the battery is LiFePO4. Any one of the BMS on the four 12 volt batteries in series can cut off the charge to the other three once it reaches what it considers a 100% state of charge.
Ah, my mistake. I didn't think anyone used Lithium for solar, very expensive and the only advantage as far as I can see is weight. Good for electric cars, no point in a concrete base garage. Any reason why someone would use Lithium?
I have put equalisers on Lead Acids aswell though, in case one cell collapses and shorts. Otherwise during charging you're cooking every cell in every battery in series with it, instead of just the other 5 cells in that battery.
I have blown up (catastrophically) a lead acid which was in parallel with 30 others. I found it scattered across the garage after I came home from holiday, along with a smell of rotten eggs strong enough to smell a few metres away from outside the garage! My neighbour thought a rat had died and rotted. I guess the only way to avoid that would be some fuses on every battery.
I have put equalisers on Lead Acids aswell though, in case one cell collapses and shorts. Otherwise during charging you're cooking every cell in every battery in series with it, instead of just the other 5 cells in that battery.
I have blown up (catastrophically) a lead acid which was in parallel with 30 others. I found it scattered across the garage after I came home from holiday, along with a smell of rotten eggs strong enough to smell a few metres away from outside the garage! My neighbour thought a rat had died and rotted. I guess the only way to avoid that would be some fuses on every battery.
LiFePO4 provides faster charging and longer life with no maintenance.
For an RV, you get more Ah for less weight. The downside is cost.
I can see the point with an RV (the weight), I was only thinking of home installations.
Do you really need faster charging with solar? Normally you'd have a battery bank big enough to take hours or preferably days to charge in bright sun, so you have a huge capacity for rainy days. I think the last one I built was 5 hot sunny summer days to fill the batteries.
I guess if you're charging it from mains off peak or with an engine or generator....
I may have gone over the top here, but I just bought one of these:
Do you really need faster charging with solar? Normally you'd have a battery bank big enough to take hours or preferably days to charge in bright sun, so you have a huge capacity for rainy days. I think the last one I built was 5 hot sunny summer days to fill the batteries.
I guess if you're charging it from mains off peak or with an engine or generator....
I may have gone over the top here, but I just bought one of these:
When the sun doesn't shine, we have to resort to a generator to charge the battery bank. The faster the battery bank charges, the less fuel the generator burns.
wattmatters
Solar Wizard
Yes, because there is only a limited time the sun is shining. You want to be able to capture as much of it as possible rather than have the charge controller throttle production.
But surely you'd have batteries big enough to store many hours of sun. Lead acids are happy charging fully in many hours.
In Australia, surely the sun always shines?
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