Volt Drops? (1 Viewer)

[donkey]

One for the electrical gurus I think.
I have twin agm hab batteries connected to Victron regulator.
Having checked the whole system I have the following.
From regulator output to batteries I have a volt drop of about 1.3v.
A bit for each section of wiring plus about .7v across the Sargent control box.
This results in a slightly low absorption voltage at the batteries.
Rewiring would improve it, but not inormously.
My question is:

As I can adjust the absorption and float voltages, would it be OK to 'adjust ' the Victron settings that would achieve the desired voltages at the batteries? Thereby negating the volt drops.

Geoff

 

[autorouter]

What exactly do you mean by a Victron regulator? Does it regulate the charge from the solar, alternator or mains charger?

A mains charger probably has 'voltage sense' wires that can be fitted, which automatically tell the charger to increase the voltage to maintain the correct battery voltage.

A Victron solar controller (if it has Bluetooth) can get battery voltage information from a 'BatterySense' module that sticks on the battery. It transmits by Bluetooth, and allows the solar controller to adjust the output voltage to the correct value.

 

[donkey]

Thanks Autorouter, that's the tool.
I had not come across it, but having now looked at spec, it will do what I want.
I guess there is not a simpler way of connecting a battery voltage sensing wire to the controller?
By the way it is a Bluesmart 100-15

Geoff

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[Raul]

Get a batt sense https://www.ebay.co.uk/itm/25501903...d=link&campid=5338547443&toolid=20001&mkevt=1, and just connect the wires to the battery post. Neg to neg and pos to pos. Open victron connect app and connect to it. Once you connected to it you will need to network the two together. It’s simple.

 

[autorouter]

I don't think it has any direct battery measurement sensing wires, like the mains chargers have. However if you get a BatterySense module and stick it on the side of the battery, it will also sense the battery temperature and adjust the voltage for that as well.

 

[donkey]

Thanks again. I see there are two versions: short and long range = 3m or 10m range. I have gone for the 10m range to future proof the system.
My main concern is undercharging the AGMs for long periods, apparently not good for them.

Geoff

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[Raul]

Thanks again. I see there are two versions: short and long range = 3m or 10m range. I have gone for the 10m range to future proof the system.
My main concern is undercharging the AGMs for long periods, apparently not good for them.

Geoff

That’s why I try to tell ppl to size the wire from controller to batts properly to reduce the voltage drop to almost 0, or reasonably practical. You can have a bit of drop from panels to controller, but not from controller to batt. Not allowed, as it will mess the settings. I have a 100/50 controller with 16mm2 cable run 0,6m max to batt. I still get some voltage drop, and use a batt sense networked with the charger to compensate for the drop. I could run a 25mm but space is tight.

 

[donkey]

That’s why I try to tell ppl to size the wire from controller to batts properly to reduce the voltage drop to almost 0, or reasonably practical. You can have a bit of drop from panels to controller, but not from controller to batt. Not allowed, as it will mess the settings. I have a 100/50 controller with 16mm2 cable run 0,6m max to batt. I still get some voltage drop, and use a batt sense networked with the charger to compensate for the drop. I could run a 25mm but space is tight.

Hi
My biggest volt drop is across the Sargent control box, with no obvious cause, more an accumulation of various components. I could bypass the Sargent but it does have some useful features.
Looking at the battery sense I think it will correct this charge at the batteries.

Geoff