Sterling B2B charger issues

henny

New member
So I’ve looked through these forums for some answers on this issue and it’s been quite difficult finding anyone with my same issue.

Chief Problem: The B2B charger is only producing 2-6a of charge to my house battery system.

Context and details:
  • 2005 t1n 158wb
  • I have the sterling power bb1260
  • I have a 150a alternator in good health- producing 14.05-14.19
  • My starter battery is in good health
  • My wires are 4awg that go from the starter battery to the B2B (my house batteries are in the rear of the vehicle)
  • Voltage readout on the wires going into the input of the B2B is anywhere from 13.95-14.05v (this, to me, confirms that I’ve selected the correct wire gauge)
  • Voltage readout on output of the b2b is anywhere from 12.70-13.15v (it seems very strange to me that the output is so much less than the input)
  • I do not have any additional electronics or hardware that runs on the van other than the DRL and the backup camera which are both always on
  • Regardless if I am driving for 10 minutes or 5 hours, my output is the same. Also regardless of my RPM’s, my output is the same
I am a bit of a loss as to why I’m not getting more charge from the b2b charger. I’m under the belief that I should be getting between 40-45a of charge to my house batteries, not 2-6a. Do I need an even bigger alternator? Does this mean my b2b is bad?

Any help here would be greatly appreciated! I’m about to head into the winter season and I’m going to have to heavily rely on my alt charger.
 

Attachments

Cheyenne

UK 2004 T1N 313CDi
How is your house battery grounded? And where are shunts, if any?

Keith.
 

henny

New member
How is your house battery grounded? And where are shunts, if any?

Keith.
My house battery is grounded by a 4awg wire from the negative bus bar straight to the body. It’s about an 18” run. I have made sure that the paint was ground off to make a good connection.

I only have one shunt between my negative terminal on my house battery bank and my negative bus bar.
 

marklg

Well-known member
Can you measure the difference between the ground voltage at the battery and the ground voltage at the Sterling? Sterling suggests to connect the ground input directly to the battery, not the body. If there is significant current flow in the path, maybe due to something else, that may be an issue and the voltage may not be zero as it should be. When lots of current flows, ground is not ground.

What are you using to measure current? Is there a battery meter shunt somewhere? It would be best for troubleshooting to use a clamp on DC Ammeter on all three wires to the Sterling. I have this one:


I did find that the Sterling needs extra cooling or it will quickly cut back to half current, about 30 A, but I did not see anything as low as you are seeing.

It might also help to draw up and share a detailed diagram of how everything is hooked up with wire sizes. Here is how mine is done. Your diagrams don't need to be a fancy, but this level of detail would really help to understand what is really going on. Very often, when I take the time to draw things out like this, I find a problem I had not seen, but that is my learning style. It goes in through the eyes, through the brain and out the fingers (to keyboard or mouse) and back into the eyes from the screen. It forces me to understand every little detail.

RV_Wiring-1.jpg
RV_Wiring-2.jpg
RV_Wiring-3.jpg


Regards,

Mark
 

Roamers

2020 4X4 170 Crew
Is this a new install? Not a B2B guru, but output voltage seems too low to charge battery. If output voltage is close to battery voltage, flow will be low. Sterling settings?
 

bsqr

Member
I was concerned about the adequacy of a chassis ground with my Sterling BB1260 when I discovered that Sterling recommends against using a chassis ground. I called their tech guy over in the UK(?) and he told me that it's not uncommon at all to get less than 10A charging when using a chassis ground. He recommended that I connect to the vehicle battery negative or directly to the negative terminal on the alternator.
 
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autostaretx

Erratic Member
Things unstated by the original question:
(a) battery chemistry/style? (flooded lead acid, gel, AGM, Lithium (which flavor)??)
(b) battery bank capacity? (amp-hours)
(c) battery state of charge before starting the engine?
(d) Does the Sterling know your battery chemistry?? (that low voltage would be suitable for some Lithiums).
(e) does the Sterling have a battery temperature sensor? (tell us the switch settings)
(if not, is the Sterling mounted in an overly warm location?) High temperature would limit charge.

(f) there's probably a bunch of "etc,etc,etc"

Voltage readout on output of the b2b is anywhere from 12.70-13.15v (it seems very strange to me that the output is so much less than the input)
Remember that the STerling is trying to do a "proper" charge ... so it's feeding the battery what the charging algorithm calls for
(you wouldn't be surprised if a "shore power" charger (120 vac feed) was only putting 13v into the battery, would you?)

--dick
 
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Shawn182

Active member
Stupid question....but are you taking the measurement when the alternator is actually delivering full current while driving and while the house battery is depleted and actually needing charging?

Kinda like solar...you are not gonna see anything of it does not need anything,
 

henny

New member
Is this a new install? Not a B2B guru, but output voltage seems too low to charge battery. If output voltage is close to battery voltage, flow will be low. Sterling settings?
This is a new install but on an old vehicle. Batteries are new, whole electrical system is new.
 

henny

New member
Stupid question....but are you taking the measurement when the alternator is actually delivering full current while driving and while the house battery is depleted and actually needing charging?

Kinda like solar...you are not gonna see anything of it does not need anything,
I only noticed this problem because of an issue with my victron battery monitor re-synchronizing in the mornings and saying there is 100% charge in the batteries when there is not 100% charge. We drive about 60-90 minutes each day, so I figured it was charging the batteries up and why it was reading 100%. One evening the batteries were completely depleted which has led me down this rabbit trail. Currently at 35% on my batteries so it should be charging much more. fwiw my solar panels are keying up fully and dumping the fully charge into the system through my victron smart solr charger.
 

henny

New member
Things unstated by the original question:
(a) battery chemistry/style? (flooded lead acid, gel, AGM, Lithium (which flavor)??)
(b) battery bank capacity? (amp-hours)
(c) battery state of charge before starting the engine?
(d) Does the Sterling know your battery chemistry?? (that low voltage would be suitable for some Lithiums).
(e) does the Sterling have a battery temperature sensor? (tell us the switch settings)
(if not, is the Sterling mounted in an overly warm location?) High temperature would limit charge.

(f) there's probably a bunch of "etc,etc,etc"


Remember that the STerling is trying to do a "proper" charge ... so it's feeding the battery what the charging algorithm calls for
(you wouldn't be surprised if a "shore power" charger (120 vac feed) was only putting 13v into the battery, would you?)

--dick
(A) my house batteries are LiFePo
(B) two, 160ah Victron
(C)both batteries are healthy, reading 3.22(+/- .01)v per cell (four cells per battery)
(D) yes, but to make sure, is it the battery chemistry of output or input? I can't seem to find that anywhere
(E) no, per the directions, this is necessary. The "garage" area in the van is where the batteries are stored and where we are it doesn't rise about 60 degrees F

I think i understand the "proper" charge. I understand that charging at about 13v should be normal but the extreme low a(h) seems unusual as i have read many other people getting 40+ amps charging back into their system
 

henny

New member
Can you measure the difference between the ground voltage at the battery and the ground voltage at the Sterling? Sterling suggests to connect the ground input directly to the battery, not the body. If there is significant current flow in the path, maybe due to something else, that may be an issue and the voltage may not be zero as it should be. When lots of current flows, ground is not ground.

What are you using to measure current? Is there a battery meter shunt somewhere? It would be best for troubleshooting to use a clamp on DC Ammeter on all three wires to the Sterling. I have this one:


I did find that the Sterling needs extra cooling or it will quickly cut back to half current, about 30 A, but I did not see anything as low as you are seeing.

It might also help to draw up and share a detailed diagram of how everything is hooked up with wire sizes. Here is how mine is done. Your diagrams don't need to be a fancy, but this level of detail would really help to understand what is really going on. Very often, when I take the time to draw things out like this, I find a problem I had not seen, but that is my learning style. It goes in through the eyes, through the brain and out the fingers (to keyboard or mouse) and back into the eyes from the screen. It forces me to understand every little detail.
Mark
I have moved the negative cable to the battery itself. At the battery, with the van running, I’m getting 14.25v, measuring at the starter battery terminals. At the sterling input, measuring the(-) and (+) on the sterling itself I’m getting 14.15v. when keep my voltmeter negative the same, and then move my positive to the output, it reads 13.00v.

Good idea to get the clip on volt monitors. I’ll order them.

temperature is not an issue. It’s currently 48 degrees where I am.

Attached is my drawing.After drawing it, could I have made a mistake by tying the (-) into the bus bar before it arrives to the sterling charger??
 

Attachments

marklg

Well-known member
I have moved the negative cable to the battery itself. At the battery, with the van running, I’m getting 14.25v, measuring at the starter battery terminals. At the sterling input, measuring the(-) and (+) on the sterling itself I’m getting 14.15v. when keep my voltmeter negative the same, and then move my positive to the output, it reads 13.00v.

Good idea to get the clip on volt monitors. I’ll order them.

temperature is not an issue. It’s currently 48 degrees where I am.

Attached is my drawing.After drawing it, could I have made a mistake by tying the (-) into the bus bar before it arrives to the sterling charger??
Thanks for the diagram. I don't have an external shunt, so not sure of how best to hook one up. My batteries have internal monitors with a bluetooth interface. What are your battery cables? Can you connect one side of the voltmeter to the battery minus and the other side of the voltmeter to the Sterling minus? If there is voltage there, the Sterling is not seeing the actual battery voltage and using bigger battery cables to the shunt and to the bus bars would help. My battery cables are AWG 1/0 and the crimps have to be made well. Poor crimps can cause voltage drops.

Maybe someone more familiar with the use of the shunts can look and tell you more.

Regards,

Mark
 

henny

New member
Thanks for the diagram. I don't have an external shunt, so not sure of how best to hook one up. My batteries have internal monitors with a bluetooth interface. What are your battery cables? Can you connect one side of the voltmeter to the battery minus and the other side of the voltmeter to the Sterling minus? If there is voltage there, the Sterling is not seeing the actual battery voltage and using bigger battery cables to the shunt and to the bus bars would help. My battery cables are AWG 1/0 and the crimps have to be made well. Poor crimps can cause voltage drops.

Maybe someone more familiar with the use of the shunts can look and tell you more.

Regards,

Mark
Im using 2/0 for my battery cables to and from the bus bars so it should be quite more than I’m needing, I think.
 

marklg

Well-known member
Im using 2/0 for my battery cables to and from the bus bars so it should be quite more than I’m needing, I think.
Check your crimps, but 2/0 should be more than sufficient.

Regards,

Mark
 

autostaretx

Erratic Member
(A) my house batteries are LiFePo
That was a critical detail!!
Proper charging voltages can vary by over a volt (and lithiums prefer lower)
(B) two, 160ah Victron
(C)both batteries are healthy, reading 3.22(+/- .01)v per cell (four cells per battery)
And now:
(D) yes, but to make sure, is it the battery chemistry of output or input? I can't seem to find that anywhere
It's the *output* (the Sterling could care less about what's feeding it ... but it damn well better care about the characteristics of the battery it's charging.
So tell the Sterling that it's talking to LiFePO4 (before it destroys them).
(E) no, per the directions, this is necessary.
I think you meant to say "UNnecessary"? Whose instructions? (Sterling or Victron battery?)
The "garage" area in the van is where the batteries are stored and where we are it doesn't rise about 60 degrees F

I think i understand the "proper" charge. I understand that charging at about 13v should be normal but the extreme low a(h) seems unusual as i have read many other people getting 40+ amps charging back into their system
I would also expect that it would try to cram the B-to-B's full rated current into depleted LiFePO4s.
... unless the Sterling thought it should be gentle.

The Sterling should also not attempt to charge the Lithiums if the battery temperature is below freezing.
(for most lithiums, the absolute limit is -5 C (23F) ... going lower will damage the batteries)
((yes, some batteries' internal BMS will also intercede, but why have only one layer of defense?))

--dick
 

henny

New member
Thanks Dick,

so I’ve got it properly set to LiFePo4, all good there.

I did indeed mean unnecessary about the temp monitor.

the battery temp has always been above freezing, so that’s good.

I did attempt to manually set the output to 14.2v on the sterling but after restart, it dropped again to 13.2-13.4v of output when it reads 14.2v of input.

my only guess is that the sterling is insisting on being gentle with the batteries?
 

marklg

Well-known member
Thanks Dick,

so I’ve got it properly set to LiFePo4, all good there.

I did indeed mean unnecessary about the temp monitor.

the battery temp has always been above freezing, so that’s good.

I did attempt to manually set the output to 14.2v on the sterling but after restart, it dropped again to 13.2-13.4v of output when it reads 14.2v of input.

my only guess is that the sterling is insisting on being gentle with the batteries?
The Sterling can't make the house battery voltage what it wants instantly. Think of the battery like a bucket of water. The filled height represents the state of charge and the voltage follows that according to the voltage-state of charge curve for the battery. So, the Sterling can only get the voltage it wants by providing current, which is like adding more water. It does have a voltage curve it wants to follow while charging a particular battery, which is derived from the voltage-state of charge curve for the battery. Now, this is a first approximation, there are leaks, and the voltage - state of charge curve varies with other things, but it helps to think of it this way when trying to troubleshoot.

That is why a clamp on DC Ammeter is so helpful. You can see how much current is actually going through each wire. Clamp it on all the wires and things become much clearer. You can read the current instantly. The voltage will change due to that current but it takes time. In fact, if it changes rapidly, there is probably a problem like a bad crimp or an unexpected short. Think a kink in the hose or a hole in the hose.

I hope this analogy is helpful. For the EEs out there, I simplified things because I did not want to involve calclulus.

Regards,

Mark
 

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