diy solar

diy solar

Batrium with second set of leads for active balancer

Stewfish

New Member
Joined
Oct 20, 2020
Messages
316
Pardon my voice to text grammar

I saw in a video that was suggested for me to watch by Batrium the gentleman had a second set of leads that he could hook up to an active cell balancer. I have not done any research in that area at all. I was hoping I could find a guru that could point me in the right direction or brand.

My goal is to:
1 charge up the cells as high as I can
2 turn off the solar breakers and the power breakers to the AC and then the power to the inverter
3 then disconnect the battery by disconnecting the batriums high leads first then the low leads
4 then connect some sort of connector which then goes to all the leads to the cells and all the leads to the cell balancer to balance a 16s 2p system
Then reverse exactly the steps after balancing

This would allow for the easiest top balancing.

I believe I would need two 16s balancers.

My thoughts on this are that I was charging my two batteries up and one of the leads failed for the batrium. I'm thinking that the bactrim was bleeding enough power off of a particular cell that it blew the lead.

This leads me to thinking that I should get the voltage up higher and top balance more often. These 32 basen 280ah cells are not similar at all. I also added a few new cells to some low performing and even a cell that died after less than a year and I don't really want to charge up the system and put everything back into parallel a few different times. I saw Will's video on active balancers and it seems like you can get quite a bit of amps moved from one cell to another vs the batrium or a daly at half an amp max with the batrium to a couple hundred mA with the daly.

This would be a maintenance option.

I would also need a directional 16 pin connectors that would be just as easy to disconnect as the Batrium, but also not mess up the order. Note: You can't run active cell balancers with the Batrium running.
 
This leads me to thinking that I should get the voltage up higher and top balance more often.

Why. If your cells are top balanced at your defined peak charge, what's the problem?

These 32 basen 280ah cells are not similar at all. I also added a few new cells to some low performing and even a cell that died after less than a year and I don't really want to charge up the system and put everything back into parallel a few different times. I saw Will's video on active balancers and it seems like you can get quite a bit of amps moved from one cell to another vs the batrium or a daly at half an amp max with the batrium to a couple hundred mA with the daly.

.5A is a lot when staying balanced regularly. The active balancers that say 4-6A are optimistic. Typically, they'll only move about 1-1.5A unless it's an extreme delta, so you're not gaining much...

This would be a maintenance option.

I would also need a directional 16 pin connectors that would be just as easy to disconnect as the Batrium, but also not mess up the order. Note: You can't run active cell balancers with the Batrium running.

Says who?
 
Why. If your cells are top balanced at your defined peak charge, what's the problem?



.5A is a lot when staying balanced regularly. The active balancers that say 4-6A are optimistic. Typically, they'll only move about 1-1.5A unless it's an extreme delta, so you're not gaining much...



Says who?
The manual

I added new cells a few days ago and want to top balance them. I cant set my charge above 55.5 volts or some cells get too high
 
I bought a set of these JKBMS 2a active balancers before and proved they work along side a set of dumb BMSs (using 2 sets of balance wires). If you search them on AliExpress you can find the same brand at 5a and 10a models too (for more money of course)... I just did bench testing (using the 2a ones) for some time with them, didn't keep the setup on (took apart the pack for now), wound up changing to JBD BMSs... If I feel like I want more balancing, I could still use these JKBMS active balancers on that too. I haven't had time to do further testing on it for awhile though... The bluetooth app for them works nice to show cell voltages if you are using dumb BMSs like I had on the first round.



Here's their website:
 
Last edited:
Even if you only needed to use one of these for a temporary period to help balance, it could be useful to have the higher 2a amp balancer around just as a bench tool to help balance if you have a pack like this where you can't take it down (like in production)... You can just wire up the balancer leads, get them back in balance, monitor with the bluetooth app, turn off the active balancing feature in the app and watch them for awhile to make sure they stay pretty close, and once you are confident you can remove the system if you wanted or just leave it on. It has a toggle in the app to turn on or off the actual balancing, and just otherwise use to monitor voltages...
 
The manual

Curious. I received no manual with my WM5 and MM8

When I ordered them, I stated my intentions to Maxine of disabling Batrium balance feature and using active balancing. She recommended I not disable Batrium balancing, but she did not say that I couldn't use active balancers. These have completely separate leads. If you were to use the Batrium sensing leads for balancing, that would be a bad idea. Maybe that's what they mean?

I added new cells a few days ago and want to top balance them. I cant set my charge above 55.5 volts or some cells get too high

Why aren't you taking them up there and letting the Batrium burn off the excess? 55.5V is only 3.47V. You should be balanced at that point quite easily.
 
Last edited:
Some of the passive balancers, balance on discharge (while others might balance on charge), so you might have to take them down to the low-end knee of the SoC curve in order to get them in balance on their own, depending on how Batrium does it...
 
Last edited:
Have a commercial 15KwHr 16S LiFePO4 storage where the supplied control system was mosfet BMS and a separate active balancer that failed and put cells 1-4 200mV lower than the rest of the pack. Removed the failed active balancer unit and added in JK 2A standalone active balancer by using the existing cell leads. Took 62 days to get delta V down to 10mV from 200mV when pack full and in standby at 56.0V.
One of the features of the Jikong Standalone 2A balancer is that it is missing an adjustment so that balancing only occurs above a set voltage (ideally 3.4V) (The Jikong combined BMS / balancer does have this feature) . To my way of thinking if top end balancing is sought its more efficient to balance only when cells are above 3.4V. Allowing balancing to occur in the rest of the curve blow 3.4V effectively unbalances the pack as voltage is not as an accurate representation of the SOC compared with the top end (>3.4V). Anyway the JK 2A balancer did fix the problem.

Theoretically the 3rd generation NEEY active balancer might be better as it can be controlled according to cell voltage and is rated at 4A and cheaper.
 
How far apart are the cells? Blockmons have quite a bit of balance capability.

I'm not sure why you just can't turn off Batrium balancing and use active balancers without disconnecting anything.
 
Lowest cells are 3.3 and highest at 3.7. With the cell bleed off at 3.45 it still can't keep up and bleed enough power to let the remaining 75% of the pack come up to charge. That is with the charger set at only 55.5 vs 58. If I go higher it stresses the cells too high. I'm not willing to only have the Batriums' .5amps try to top balance a new pack with that much power balancing needed. I need to top balance and don't want to tear down the 32 cell battery after charging.

I found two 16s 5a balancers on Amazon prime to balance asap. You can't do balancing w batrium leads bc the leads can't handle that amperage. They are thin enough to act as a secondary fuses on purpose.

I will just bulk charge and then turn everything off just like a tear down type balance so turn off the charger breakers, inverter breakers and power button, and disconnect the batrium power and leads, then balance easily w the leads to the two 5a balancers. I'll do that a few times and try to get everything up to atleast 3.5v to 3.6 instead of 3.3.
 
Lowest cells are 3.3 and highest at 3.7. With the cell bleed off at 3.45

Ouch - that's a mile. Why not start earlier at 3.40?

Charge the individual laggers with 10A supply (assuming you have one).

it still can't keep up and bleed enough power to let the remaining 75% of the pack come up to charge. That is with the charger set at only 55.5 vs 58. If I go higher it stresses the cells too high. I'm not willing to only have the Batriums' .5amps try to top balance a new pack with that much power balancing needed. I need to top balance and don't want to tear down the 32 cell battery after charging.

I found two 16s 5a balancers on Amazon prime to balance asap. You can't do balancing w batrium leads bc the leads can't handle that amperage. They are thin enough to act as a secondary fuses on purpose.

I can't imagine why anyone would attempt to do that. There's a big difference between, "You can't use the batrium leads for active balancing" vs. "You can't use active balancing with the batrium attached" - you most certainly can - you just have a second set of leads for the balancer.

The 5A is optimistic. Mine are 6A. The most I've seen them put out is 1.5A, and that's with Lithium NMC which has a direct voltage to SoC relationship and a wider operating range.

Care to share the balancer?

I will just bulk charge and then turn everything off just like a tear down type balance so turn off the charger breakers, inverter breakers and power button, and disconnect the batrium power and leads, then balance easily w the leads to the two 5a balancers. I'll do that a few times and try to get everything up to atleast 3.5v to 3.6 instead of 3.3.

Why not just add the balancer to the terminals separate of the batrium leads? You're going to need to charge while balancing. Do you really want to trust the active balancers without individual cell monitoring?
 
Here is my way i do when introducing new cells in 16S battery. Considering you have not very old pack already.
I use 6 benchtop power supplies and attach each to one cell in pack and set all to predetermined cell voltage i would love to see. Once i finish i move to othe cells and repeat. Once all are done inspect all cells with calibrated volt meter and confirm all cell voltage are within tolerance. This can be done without removing any cell terminals. Have all power users removed while you doing it. If married with other packs in parallel make sure you hit same pack voltage with rest of them.
Warning this advice is not for beginners if you are not advanced user, follow directions how to arrange all cells for parallel and charge this way.
Good luck and stay safe.
Also when playing with my advice make sure nobody is bothering you not even your better half while you playing with it.
 
Back
Top