German made BMS?

[jbibler]

Does anyone know of a German made BMS system? Talking with an engineer at a particular battery company he told me that they stopped working with all the China made BMS systems and have switched to a German made BMS that has been flawless. Unfortunately, he would not give me any other information about the company or the configuration they are using on those BMS.

I'm looking for a 12v - 4s 200-250 amp BMS for cranking Yamaha 300 hp outboard.
I'm also looking for a 36v - 12s 60-80 amp BMS for the trolling motor battery.

I'm using a Power-Pole Charge onboard battery charging system. It's smart charger that moves current between batteries on the run and at rest and can be adjust to give priority to either the house cranking battery or the trolling motor battery.

I currenty have DALY BMS on each battery bank and have had a good amount of issues. I want to replace them and was planning to go JBD or JK. I've used JBD on other 48v builds and have not had an issue to date. The primary issue that I'm having right now is fairly well known and has been resolved from a few of the battery manufacturers, but I have not been able to resolve it on my own with the DALY units.

The issue: The alternator from the Yamaha is supposed to stop sending current to the batteries when they are full. However, as soon as the battery hits 100% SOC the BMS disconnects charge input, voltage spikes as the current from the alternator has nowhere to go and the motor shuts off to protect itself. Is there a way to more gracefully disconnect the BMS so that the motor has more time (a few seconds) to react and stop sending current from the alternator?

I've read up some about adding a Balmar regulator along with a alternator protection module. However, adding additional aftermarket parts is not ideal and other battery manufacturers have clearly resolved this issue through the BMS alone. Any information from someone knowledgable about the situation would be greatly appreciated. I think ultimately I'm still going to replace these DALY BMS with a higher quality component.

Thanks,
Josh B.

 

[sunshine_eggo]

Does anyone know of a German made BMS system?

Nope.

The issue: The alternator from the Yamaha is supposed to stop sending current to the batteries when they are full. However, as soon as the battery hits 100% SOC the BMS disconnects charge input, voltage spikes as the current from the alternator has nowhere to go and the motor shuts off to protect itself. Is there a way to more gracefully disconnect the BMS so that the motor has more time (a few seconds) to react and stop sending current from the alternator?

This doesn't sound like a 100% SoC issue. This sounds like a top balance issue. If one or more cells hit 3.65V first, the BMS cuts charge.

Did you top balance your battery?

If your battery is perfectly balanced, it should be able to hit 14.6V, and your alternator shouldn't output that voltage. Is your alternator regulator functioning properly?

Another potential issue could be over-current. BMSs aren't always symmetric. DALY is notably one of them where the charge current limit is half the discharge limit. LFP batteries tend to draw more current from alternators.

 

[jbibler]

This doesn't sound like a 100% SoC issue. This sounds like a top balance issue. If one or more cells hit 3.65V first, the BMS cuts charge.

Did you top balance your battery?

If your battery is perfectly balanced, it should be able to hit 14.6V, and your alternator shouldn't output that voltage. Is your alternator regulator functioning properly?

Another potential issue could be over-current. BMSs aren't always symmetric. DALY is notably one of them where the charge current limit is half the discharge limit. LFP batteries tend to draw more current from alternators.

Thanks for responding.
I did top balance each sell individually when I built them originally. Although the BMS has an active balancer, I do notice that the first cell in the pack on the cranking battery is always higher than the other cells. It's also the cell that trips the over voltage alarm when I experience the issue. Of course after the over voltage when the battery is at rest the cells balance back out.

Through all my issues, I've never seen an over current alarm on anything.
From what I've read, is that the Yamaha Alternator or Alternator Regulator needs a second or two to realize the battery is full and stop sending current. With a lead acid battery or an AGM battery it can absorb that extra current for a few seconds. However with a BMS on Lithium once it hits 100% SOC it immediately stops the input of current. The remaining current in route from the alternator has nowhere to go and causes the voltage spike.

I will go ahead and start top balancing my cells again manually, but keep the info coming in the meantime.
Thanks,
Josh B.

 

[sunshine_eggo]

Thanks for responding.
I did top balance each sell individually when I built them originally.

Proper top balancing is putting all cells in parallel and charging to 3.65V. If you did not do this, you did not top balance them.

Although the BMS has an active balancer,

These can be counter productive unless they can be programmed to operate only above 3.40V. They can actually undo a top balance.

I do notice that the first cell in the pack on the cranking battery is always higher than the other cells. It's also the cell that trips the over voltage alarm when I experience the issue. Of course after the over voltage when the battery is at rest the cells balance back out.

Nope. Balance is not about voltage. Balance is about state of charge. Voltage and balance are only analogous when above 3.40V/cell and more so as you approach 3.65V.

Through all my issues, I've never seen an over current alarm on anything.

Had to mention it as a possibility. You've established above that it's a top balance issue.

From what I've read, is that the Yamaha Alternator or Alternator Regulator needs a second or two to realize the battery is full and stop sending current. With a lead acid battery or an AGM battery it can absorb that extra current for a few seconds. However with a BMS on Lithium once it hits 100% SOC it immediately stops the input of current.

Nope. It's not about hitting 100%, it's about engaging over-voltage protection. They often occur simultaneously, but there is NO logic based on 100% SoC.

If the BMS does not engage charge protection, the alternator will naturally taper current to maintain the charge voltage and should terminate charge without issue.

Still important to confirm the alternator regulator is functioning properly and what it's peak voltage is.

The remaining current in route from the alternator has nowhere to go and causes the voltage spike.

Very common issue with cell imbalance on solar chargers as well. I've seen them hit mid-20V.

I will go ahead and start top balancing my cells again manually, but keep the info coming in the meantime.
Thanks,
Josh B.

If the active balancer is functioning, simply hold the battery at progressively elevated voltages until the cells are all at 3.65V.

 

[jbibler]

Proper top balancing is putting all cells in parallel and charging to 3.65V. If you did not do this, you did not top balance them.

Thank you very much for all the info, I was not aware that I needed to parallel all of the cells. I thought if I individually charged each cell to 3.65 they would be good. I'll get to work on doing this and report back after I verify all the cells are top balanced correctly. I'm assuming if I parallel all the cells and set my charger at 3.65 when it stops drawing any current 0.00 that I'm finished? Any other test I should do to verify it's completed correctly?

Josh B.

 

[Johneb]

I believe it is the Marquardt bms. From the write ups it is a step or two ahead. Try to find one though. https://www.marquardt.com/us/magazine/battery-management-system/

 

[sunshine_eggo]

Thank you very much for all the info, I was not aware that I needed to parallel all of the cells. I thought if I individually charged each cell to 3.65 they would be good. I'll get to work on doing this and report back after I verify all the cells are top balanced correctly. I'm assuming if I parallel all the cells and set my charger at 3.65 when it stops drawing any current 0.00 that I'm finished? Any other test I should do to verify it's completed correctly?

The issue with individual charging is charge loss over the time you spend charging all 4 cells, i.e., cell 1 will have lost a little charge as you charge 2, 3 and 4.

In the current state, if you simply charged each cell to 3.65V and then swept back through all four hitting 3.65V within a minute or two of each other, I would call that good enough.

Since a starting application is not conducive to maintaining cell balance, you may need to do this periodically.

Please show your balancer settings.

 

[Hedges]

How about Slovania? South of Germany and Austria.

Contact – REC BMS

www.rec-bms.com

For marine applications among others.

REC-BMS-Product Line Overview

A Quick functions and Features REC-BMS-Product Line Overview

ogm-energy.com

 

[jbibler]

Just a quick update on my situation.
I went through my cells and individually charged them to 3.65, most all of them dropped to around 3.45-3.49 afterwards.
After putting a load on them for a bit and getting them down about 10% I plugged the charger back in. I noticed that while the DALY BMS "balancing" button is illuminated during charge it just does a terrible job of keeping up with it. It didn't take long for one of the cells to hit over-voltage and cut off charging. Over the entire pack I had two cells that seemed to climb much higher than the others.

This weekend, I received my JBD BMS and installed them. Prior to disconnecting the DALY I did draw the battery back down some. After installing the JBD BMS I could see the balancing go to work immediately without charge input. After letting the new JBD BMS sit for a few hours it showed all cells in balance. I plugged in the charger and let it top off and had zero cells out of balance.

I have not had a chance to use the boat and start/run the engine, so I will do some additional testing as soon as I can and report back if I'm still experiencing any issues. Hopefully the new BMS will keep the cells balanced better and it will resolve my issues.

Thanks,
Josh B.

 

[Hedges]

What charge current and what voltage setting resulted in hitting over-current with Daly?
I'd think a lower voltage, whatever keeps the cell below disconnect, would allow balancing to take place.

It sounds like the 3.45V (for most all) cells was high enough that JBD performed balancing.
Were the outliers higher or lower? If two cells were higher then JBD may have bled those down enough.

What are the balancing current capabilities for the two BMS? Voltage range?
Since you didn't ask both to do the same task, can't tell if JBD was actually more capable.

 

[Ampster]

Ten years ago I used an EMUS BMS which was made in Lithuania. It is still sold in US and is designed for the EV conversion market. Since then they have come out with a 16S version for the stationary storage market. It is priced similar to the Orion Jr.

 

[Fish Freak]

Just a quick update on my situation.
I went through my cells and individually charged them to 3.65, most all of them dropped to around 3.45-3.49 afterwards.
After putting a load on them for a bit and getting them down about 10% I plugged the charger back in. I noticed that while the DALY BMS "balancing" button is illuminated during charge it just does a terrible job of keeping up with it. It didn't take long for one of the cells to hit over-voltage and cut off charging. Over the entire pack I had two cells that seemed to climb much higher than the others.

This weekend, I received my JBD BMS and installed them. Prior to disconnecting the DALY I did draw the battery back down some. After installing the JBD BMS I could see the balancing go to work immediately without charge input. After letting the new JBD BMS sit for a few hours it showed all cells in balance. I plugged in the charger and let it top off and had zero cells out of balance.

I have not had a chance to use the boat and start/run the engine, so I will do some additional testing as soon as I can and report back if I'm still experiencing any issues. Hopefully the new BMS will keep the cells balanced better and it will resolve my issues.

Thanks,
Josh B.

Hey JBibler;

Just following you here because I'm in the same boat as you, as in, trying to make a DIY LifePO4 cell pack work for marine/auto engine starting and charging from the alternator and am looking for a higher quality BMS overall. Bluetooth app on phone is important for me, have you used that?

Also making 36v (three 12.8v in series) trolling motor batteries. Did you also DIY deep cycle Lithium batteries? If so, which BMS did you have success with, or are you still struggling with Daly? I'll learn from your experience with Daly and avoid those....

 

[hwy17]

I believe the primary developer(s) for foxBMS are in Germany.

It's open source and you can buy a prepackaged and commercialized version of it with hardware from Nuvation, a USA/Canada company.

A battery company may well be using their own implementation of foxBMS on custom hardware.

 

[jbibler]

What charge current and what voltage setting resulted in hitting over-current with Daly?
I'd think a lower voltage, whatever keeps the cell below disconnect, would allow balancing to take place.

It sounds like the 3.45V (for most all) cells was high enough that JBD performed balancing.
Were the outliers higher or lower? If two cells were higher then JBD may have bled those down enough.

What are the balancing current capabilities for the two BMS? Voltage range?
Since you didn't ask both to do the same task, can't tell if JBD was actually more capable.

The charge current was 25 amps, 14.6 volts.
I watched it and the JBD BMS did bleed down the two cells to get them into balance prior to charging.
The current balance settings are set at Start Voltage 3.3v and the delta to balance is .15v (15 mV).
Max voltage is 3.65 and I have them set to charge to 90% of capacity.

It seems to be doing a good job so far, but have still haven't had a chance to put it through a real world test.

Josh B.

 

[jbibler]

Hey JBibler;

Just following you here because I'm in the same boat as you, as in, trying to make a DIY LifePO4 cell pack work for marine/auto engine starting and charging from the alternator and am looking for a higher quality BMS overall. Bluetooth app on phone is important for me, have you used that?

Also making 36v (three 12.8v in series) trolling motor batteries. Did you also DIY deep cycle Lithium batteries? If so, which BMS did you have success with, or are you still struggling with Daly? I'll learn from your experience with Daly and avoid those....

I'm using JBD BMS with Bluetooth & balancing. So far, I'm happy with them. In addition to these marine batteries, I also built a 48v (16s - 105ah) battery for my golf cart. It's using a JBD BMS from the start and have had no issues. It's a 250 amp BMS and has done a great job of balancing as well. I should have ordered a JBD BMS from the start for my marine batteries, but thought I would try the DALY units. I don't have any complaints with them except the balancing functionality. That could be a direct result of it being used for a cranking battery that experiences higher momentary draws and charging. But I would still skip them if I were you.

But for my boat I built a 12v - 105 ah (4s) crank battery and a 36v - 105ah (12s) battery. I'd recommend creating a single 36v bank with a 12s 36v BMS opposed to trying to put three 12v batteries in series. It's just a cleaner install and easier to manage via the Bluetooth app.

Josh B.

 

[Fish Freak]

I'm using JBD BMS with Bluetooth & balancing. So far, I'm happy with them. In addition to these marine batteries, I also built a 48v (16s - 105ah) battery for my golf cart. It's using a JBD BMS from the start and have had no issues. It's a 250 amp BMS and has done a great job of balancing as well. I should have ordered a JBD BMS from the start for my marine batteries, but thought I would try the DALY units. I don't have any complaints with them except the balancing functionality. That could be a direct result of it being used for a cranking battery that experiences higher momentary draws and charging. But I would still skip them if I were you.

But for my boat I built a 12v - 105 ah (4s) crank battery and a 36v - 105ah (12s) battery. I'd recommend creating a single 36v bank with a 12s 36v BMS opposed to trying to put three 12v batteries in series. It's just a cleaner install and easier to manage via the Bluetooth app.

Josh B.

Very nice Josh, and I like that 36v recommendation, with a challenge is making a container for the 12s 36v cells, or maybe I only need to make a splash shield for the BMS and the cells can be open? I'm using Frey cells that have top/bottom caps you can connect with 4 long all-thread rods and has plates for the ends. The BMS needs open air cooling right?

Did you use the same brand smart bms for the crank and deep cycle batteries? Can you describe your crank situation and estimated crank draw? I'm certain my cells can handle the burst but can the bms? I'm cranking a 225 Mercury OptiMax outboard, or a 302 Ford small block V8.

The other reason I wanted to make several 12v cells and 3s to 36v is for charging. Was planning on getting a 4 bank 12v waterproof marine charger. That and I'm pulling the trigger soon on a brushless trolling motor that can be run in 24v mode or 36v, so some days I'll run it in 24v to lighten the load if you know what I mean? Can you PM me a link of where you bought the JBD BMS (Alibaba preferred)?

 

[Hedges]

For cranking, I might bypass BMS, go direct to cells.
Have BMS power the starter solenoid so it can prevent cranking if cell voltages out of bounds.
Not sure whether you will be able to have shunt measure starter current; would have to tell BMS not to disconnect for that. So long as cranking is a fraction of Ah capacity, not measuring it just means error, which will get reset next time fully charged.

 

[Fish Freak]

For cranking, I might bypass BMS, go direct to cells.
Have BMS power the starter solenoid so it can prevent cranking if cell voltages out of bounds.
Not sure whether you will be able to have shunt measure starter current; would have to tell BMS not to disconnect for that. So long as cranking is a fraction of Ah capacity, not measuring it just means error, which will get reset next time fully charged.

My only concern is damaging the cells, because I don't really know how many amps starting will draw? My cells have a 2C discharge so my 100A module should only burst 200A. Don't many BMS handle that high amp? I've looked into putting a shunt inline, but didn't find a bms that could use shunt info...

 

[Hedges]

Probably several use an external shunt, e.g. REC (premium product and price). Cheap ones might use a trace on the PCB.

REC Active BMS – REC BMS

www.rec-bms.com

There are tiny LiFePO4 jumpstarters. I got one from Harbor Freight that says 300A. Here's one for 1500A.
Perhaps their batteries are optimized for higher current, but I'll bet your 100 Ah cells could do quite a bit, probably thousands of amps. The question of course is damage.

LOKITHOR J1500 Jump Starter with LiFePO4 Safety Battery 1500Amp

LOKITHOR J1500 LiFePO4 jump starter for cars features a safe LiFePO4 battery and 1500A super start current, capable of jump-starting up to 7L gasoline or 4.5L diesel engines.

www.lokithorshop.com

This 100 Ah cell says 500A for 5 seconds. Which still comes up short compared to automotive lead-acid battery, something like 700A for a minute.

Industrial LiFePo4 Cell – 100ah 3.2v – 200 Amp Discharge Rating – Overkill Solar

overkillsolar.com

CCA: 30 seconds at -18 degrees C, 7.2V minimum. (give or take whos standard.)

What Are Cold Cranking Amps & What does CCA Mean? - Power Sonic

We discuss what cold cranking amps are and what is the meaning of cranking amps. We look at DIN and JIS standards for CCA & CA, Discover more

www.power-sonic.com

 

[Fish Freak]

Probably several use an external shunt, e.g. REC (premium product and price). Cheap ones might use a trace on the PCB.

REC Active BMS – REC BMS

www.rec-bms.com

There are tiny LiFePO4 jumpstarters. I got one from Harbor Freight that says 300A. Here's one for 1500A.
Perhaps their batteries are optimized for higher current, but I'll bet your 100 Ah cells could do quite a bit, probably thousands of amps. The question of course is damage.

LOKITHOR J1500 Jump Starter with LiFePO4 Safety Battery 1500Amp

LOKITHOR J1500 LiFePO4 jump starter for cars features a safe LiFePO4 battery and 1500A super start current, capable of jump-starting up to 7L gasoline or 4.5L diesel engines.

www.lokithorshop.com

This 100 Ah cell says 500A for 5 seconds. Which still comes up short compared to automotive lead-acid battery, something like 700A for a minute.

Industrial LiFePo4 Cell – 100ah 3.2v – 200 Amp Discharge Rating – Overkill Solar

overkillsolar.com

CCA: 30 seconds at -18 degrees C, 7.2V minimum. (give or take whos standard.)

What Are Cold Cranking Amps & What does CCA Mean? - Power Sonic

We discuss what cold cranking amps are and what is the meaning of cranking amps. We look at DIN and JIS standards for CCA & CA, Discover more

www.power-sonic.com

Hey Hedges,

Very interesting, that REC bms, I'll have to research it more. Seems like a big HD relay would be what engine starting would need, right?

I've noticed that tiny jumpstarters can kick out massive amps compared to their capacity. That's crazy, 1,500A! Looks like some kinda pouch cell? I guess it comes down to the terminal's connection to the cell, that it can handle the current?

That overkill 100A cell is THE EXACT cell I'm using, I've got the 100A's and the 60A's. They have the largest terminals I've been able to find. You're right about my cells being able to do far more than 2C, but the key there is doing it less than 5 seconds. That's a long time for starting an engine.

My hunch is the way a LifePO4 lithium cell delivers it's burst amps is better than SLA, because I'm seeing LOTS of LifePO4 batts with only a 500a rating working to start engines 'requiring' 800-1,000 CCA. I haven't cut one of those open or tested that theory myself but I've got the cells to try it with. It'd be nice if there was a 500a smart bms with a huge relay and fat wire terminals, just to ensure that I don't go past the point of no return with these cells.