Small parasitic current (BatteryMaster and Lithium?)

gerry mcg

gerry mcg

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I've noticed a small (200mA / 0.2A) current drain being recorded on my BMV700 that appears to be happening when all power is off on the van since I have had my lithium batteries installed along with a Votronic VCC1212-50 B2B.
I can't think what could be causing it, but I wondered if it is perhaps the VanBitz Battery Master taking a little bit of current from the lithium battery that is sitting charged at 13.4v and passing that to the Starter battery (rather than the lower voltage of the old AGM Leisure battery at 12.9V to 13.0V) as there is now sufficient voltage differential between the lithium battery and the starter battery

I have now got a victron Smart battery Sense fitted to the lithium battery to provide temp data to the victron MPPT, but that should only draw 20mA, so 1/10th of the noted currently draw.

Edit. The BM light is red, that indicates there is current being drawn

Any thoughts?
 
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Our van takes 200ma with just the power switch on. I think it's the van heating control board, it needs to be on so it can run the fans to cool itself down after being used. Not 100% sure though.
 
I had a similar issue with a Sterling model. The voltage was permanently above the fixed trigger voltage. The Battery Master is more sophisticated using voltage differential but I guess the outcome could be the same, permanently on. I replaced the Sterling with a Victron 1212-9 which has an adjustable output voltage and a remote switch, I connected a 12V time clock to the switch connection and have set it to run for 20 minutes each day. It keeps the engine battery healthy with only a minimal draw on the leisure battery.

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by means of an update, i unplugged the BatteryMaster from the EBL and the current draw dropped from 0.1A to 0.2A to 0.0 A instantaneously, so i guess it is the BM placing a small current draw due to the imbalance between the charged lithium at around 13.2v and the starter battery at 12.4V

i guess this is how the BM works - [Broken Link Removed]
“It is designed that when the engine battery drops half a volt below the leisure battery, Battery Master automatically adjusts the charge and tops up the engine battery.”
eddievanbitz, any thoughts about how the BM works with lithium’s higher voltages?
Thanks
 
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If your starter battery is at 12.4V then the BatteryMaster is doing its job and charging it. 12.4V is not anything like 100% charged, so it's good that it's being charged. If a lead-acid battery is kept at below 100% for a long time (several weeks) without being charged to 100% occasionally, it will 'sulphate'. The lead sulfate that normally forms during discharge will become crystalline over time, and can't be turned back into the other chemicals during charging. The battery will gradually lose capacity, even though it goes through the charge cycle as normal.
 
autorouter said:
If your starter battery is at 12.4V then the BatteryMaster is doing its job and charging it. 12.4V is not anything like 100% charged, so it's good that it's being charged. If a lead-acid battery is kept at below 100% for a long time (several weeks) without being charged to 100% occasionally, it will 'sulphate'. The lead sulfate that normally forms during discharge will become crystalline over time, and can't be turned back into the other chemicals during charging. The battery will gradually lose capacity, even though it goes through the charge cycle as normal.
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My van is coming up to 5yrs old, so it is possible the starter battery is on its way out?
What should a resting voltage of a starter battery be? 12.7V?

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gerry mcg said:
by means of an update, i unplugged the BatteryMaster from the EBL and the current draw dropped from 0.1A to 0.2A to 0.0 A instantaneously, so i guess it is the BM placing a small current draw due to the imbalance between the charged lithium at around 13.2v and the starter battery at 12.4V

i guess this is how the BM works - [Broken Link Removed]
“It is designed that when the engine battery drops half a volt below the leisure battery, Battery Master automatically adjusts the charge and tops up the engine battery.”
eddievanbitz, any thoughts about how the BM works with lithium’s higher voltages?
Thanks
Click to expand...
Your engine battery is past its best I’d guess
 
gerry mcg said:
My van is coming up to 5yrs old, so it is possible the starter battery is on its way out?
What should a resting voltage of a starter battery be? 12.7V?
Click to expand...
It does sit at 12,7v, but not for long. Lead has a self discharge characteristic, much higher than lithium. The battery master does its job, it replaces the self discharge current to maintain a set voltage.
 
gerry mcg said:
What should a resting voltage of a starter battery be? 12.7V?
Click to expand...
Unless you disconnect your start battery you are never likely going to see a true resting voltage.. the start battery is generally speaking always under some sort load , all be it small..but that is sufficient to keep the voltage subdued... so with no charging source 12.4v to me could ve quite reasonable..
If its been well maintained and kept charged..imo a good quality battery could well last another 4 years...
Andy
 
gerry mcg said:
A new starter battery is only £100, so cheap peace of mind
www.batterymegastore.co.uk

Varta H3 Silver Dynamic Car Battery: Type 019

With Free Delivery, the Varta H3 Silver Dynamic is the premium battery for non-start-stop vehicles. For extra power and premium performance.
www.batterymegastore.co.uk www.batterymegastore.co.uk
Click to expand...
Put our Reg number in and they only list suitable AGM batteries at twice the cost 😭 Tayna is the same.

Our starter battery is over 7 years old so I'll replace before going abroad again.

Ford puma 2.2 engine in our boxer.

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The X290 (without a smart alternator) is not an AGM battery..

X290 Peugeot Cab/Starter Battery?

I would like to replace the cab/starter battery on my March 2015 X290 Peugeot Boxer motorhome (although I would imagine that a X290 Fiat Ducato would be the same). But I have visited several online battery sales sites and none can identify a matching battery. Some dont even recognise my registrat...
forums.outandaboutlive.co.uk
It says
“FIAMM 95Ah 800A starter-battery that was originally fitted to my 2015 Ducato X290. It’s a ‘maintainable’ type of battery, in that its cell caps can be unscrewed allowing the electrolyte-level to be checked and - if necessary - topped up.”

i had a look an my starter battery in my Nov 2016 build Euro 6 x290 is the same FIAMM 95Ah 800A, so a simple lead acid battery
 
gerry mcg said:
The X290 (without a smart alternator) is not an AGM battery..

X290 Peugeot Cab/Starter Battery?

I would like to replace the cab/starter battery on my March 2015 X290 Peugeot Boxer motorhome (although I would imagine that a X290 Fiat Ducato would be the same). But I have visited several online battery sales sites and none can identify a matching battery. Some dont even recognise my registrat...
forums.outandaboutlive.co.uk
It says
“FIAMM 95Ah 800A starter-battery that was originally fitted to my 2015 Ducato X290. It’s a ‘maintainable’ type of battery, in that its cell caps can be unscrewed allowing the electrolyte-level to be checked and - if necessary - topped up.”

i had a look an my starter battery in my Nov 2016 build Euro 6 x290 is the same FIAMM 95Ah 800A, so a simple lead acid battery
Click to expand...
Ours is X250 2014 I remember the 'wrong battery' problem when ours was new. Don't know what our battery is but it's always been fine, I'll sort it when we get home 😎
 

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