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After startup at low engine rpm the system goes to bulk and charges at 20 to 30 amps.
When rpm is raised the amps increase as does the voltage to 14.1 volts. That is the VBat set point in line
$CPA. The unit goes to Float and stops charging. The SOC is well below 100 %. How to keep charging without
raising the Kilovault battery set point above the max setting ? The alternator is a Balmar 60 - 120 amp which is
more than adequate.
Don
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Don, the WS500 is doing exactly what it is supposed to be doing, so lets look more closely at your battery pack.
The problem seems to be with your SOC reading. Remember that SOC is just a calculation of what comes in vs what goes out and an allowance for efficiency losses.
A couple of things to try:
- Research how your BMS calculates and resets its SOC reading. Most BMSs will do a reset to 100% when it reaches its maximum pack voltage(which yours seems to be doing)
- If there is a slight difference in readings between your cell pack and the WS500 you might try increasing your VBAT setting by a tenth or two of a volt and monitor it closely while charging, just to get it to its 100% reset trigger point.
The big thing to remember here is that SOC is just a calculation and can easily get out of whack over time with just the smallest of error in sensing values.
Hope this helps,
Rick
OGSS Tech support
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Have been monitoring SOC with the Balmar SG 200 and Kilovault bluetooth app.
The Kilovault app reads consistently higher by 7 to 15 % so I have been switching to internal regulation at the alternator in order to raise the charge up to 90/95 % of the battery capacity without having the WS 500 shut down.
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Most battery packs are set to 14.4 and fine up to 14.6 volts, provided they are fairly well balanced. You are likely better off using your WS500 and increasing the VBAT setpoint vs relying on an internal regulator with no proper shutoff or temperature safety cutoffs.
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Hello Don,
from KiloVault manual.
Absorb Voltage 14 Volt
Absorb End Amps 2 A
Absorb Time 2 minutes or less
Not clear for me, is what they like, 14.0V only for 2 minutes, or 14.0 till the amps drop below 2Amp.
The WS500 can be programmed for both charge profiles.
This means as Rick mention, the WS500 is doing what it should do.
If there is 14V, for 2minutes on the battery pole, the internal software, should reset the SOC reading to 100%.
If thats not happen, you need to ask Kilovault when there SOC should reset to 100%.
Iam curious how the Kilovault is doing his internal balancing, because most off the other brands do balancing between 14.0 and 14.4 volt. My personal test show that balancing below 14.0V is not efficient, and created in some cases a bigger imbalance.
Lower charge voltage seams better for lifetime from the lifepo4 cells, but higher voltage are needed to keep the cells in balance.
Anyway I think you need to follow the manufacture charge advise, higher as 14.0 I would discuss with manufacture.
Your internal regulator will keep the batteries longer as 2 minutes in Bulk, not good.
As your charge voltage is maximum 14.0V, the Balmar battery monitor should reset to 90 or 100% also. Check there manual how to archive this.
Another point thats important, is your voltage sense from the ws500 installed at the correct position.
Ben
Forum reader
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Have contacted Kilovault and received a reply that is basically what they have printed in their brochure.
Limit the voltage to 14.1 v. Since then I have raised the VBat set point to 14.2 volts. anyway.
This resulted in a slight improvement. The system stayed in bulk longer , then went to acceptance and stayed for several minutes until the rpm was raised to about 1500rpm , then went to float and quit charging. When the rpm was raised the voltage at the alternator and battery sense increased slightly to 14.3/14.4 volts. It does appear that the WS 500 is working properly but there does not seem to be a way to allow the battery to reach full charge. Since Kilovault says not to raise the set point , the other alternative is to somehow lower the max amperage of the alternator. How ? I have difficulty understanding when and how the the battery will reach full charge. The Balmar SG 200 has never gone above 65% and the Kilovault App 90 %
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This is a great example of what happens when the Smart regulator can not talk with the BMS. With an integrated system the BMS will send a signal to the WS500 to start to taper back as it approaches 100%.
In your case you will have to go to a semi-automatic method. The WS500 has an option, using the feature IN input to reduce its output when a switch is closed.
From what it seems, your Battery pack may be out of balance and even though it is not 100% full, you have a cell that is going over voltage, while other cells are not yet full, but the total voltage goes above 14.1 because when a cell reaches 100% full its voltage will start to rise exponentially as compared to the other cells. Your idea to slow feed it while it approaches 14.1v may work, all depending on how the internal BMS will try to top balance your cells. Kilovault may be able to assist with a maximum input amp rating while balancing.
This is from page 11 of the manual
http://wakespeed.com/Wakespeed%20%20Communications%20and%20Configuration%20Guide%20v2.4.3.pdf
A NOTE ON FEATURE-IN PORT
The Feature-in port allows a wide range of optional capabilities in the WS500 to be selected in real time. Throughout
this configuration guide there are a number of places where the Feature-In port may be enabled to be looked at to
select a given capability. There are also options to modify the behavior of the Feature-In port from its normal behavior.
Care should be exercised when configuring the WS500 to assure that the desired behavior of the Feature-in port is
selected, and that some other expected use has not inadvertently been disabled. Example, by utilizing the Feature-In
port to allow to selection of an alternative DC-DC converter set point, the default behaviors of forcing the regulator
mode to Float with CPE #8 will be overridden; this could cause unexpected behaviors if the system design expects to use
the Feature-in port for a legacy BMS integration.
Feature-In can be used as
1. Force Equalize (when using CPE #7)
2. Force Float (when using CPE #8)
3. Force whitespace (setting RMP to positive value in CNG when in CPE #8. Negative value of RPM in CNG forces
whitespace on all the time ignoring Feature-In. Pos/New values of RPM in CNG are ignored when in CPE 7.)
4. Force regulator power (setting dHalf 0 in SCA)
5. Feature-In polarity change for any of the above.
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Thanks for the suggestion. I had the chance today to check the cells with the Kilovault App. They measure in miliamp - 3287, 3288, 3288, and 3283. The voltage at rest is 13.1 v and SOC 76 %. Will have one more chance this year to determine why the battery is not reaching full charge . Thanks for all your help with this issue.
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Hello Don,
If the cell voltage are in balance at 13.1V, maybe they are out off balance at charging voltage from 14.1V
I am not sure about kilovault but in general the SOC is reset to 100% if all cells reached a certain programmed Volt level.
If there is a unbalance it could that at 14.1V, one cell is below this value, therefore soc is not reset to 100%.
Please post the cell voltage from your app, when the charge voltage is 14.1Volt on battery terminals.
Can you post a picture from your setup, where I can see where your cable 10(black) and cable 11(red) is mounted.
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Problem solved. Moved the positive sense from the alternator side of the switch to the battery post. Am able to oper ate the engine at 3000 rpm and achieve 14.06 volts and 82 amps. Brought the SOC up to 99 % measuring with the Kilovault bluetooth app. Alternator temp raises quickly with the insulated box . Just opening it a few inches allows the temp to fall to a safe level. Will probably have to reduce alternator output to around 60 amps. What is the best way to achieve that in the WS 500 ? Thanks for the help . This forum and the software from OFF Grid is great.
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Don, not sure if we got an answer to you on this one.
You can use the derate setting in the SCA parameter. This will limit the field output.
The PBF,(Pull back Factor) can also be used in association with RPM to reduce the output based on engine speed.
Snip from the WS500 config tool attached for reference
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Thanks for your answer. Now the issue is heat created by charging the LFP battery at a high rate of current with the large 120 amp Balmar and small Yanmar engine -21 hp. Are there any external add on rectifiers available for the alternator to reduce the heat problem or is the Grasser alternator the only one available ?
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I have had success in the past by adding a hose attachment (or making one from a big funnel) to the back of the alternator and bringing in cool outside air. In one case I even added a bilge blower. Certainly worth a try before swapping alternators.
