question

Robert Baker avatar image
Robert Baker asked

Are 2 SmartSense temperature monitors best for a 2 battery Lithium bank?

I have the following on my sailboat.

Starter Battery Bank1 which 1x100AH AGM

Charged by... Valeo Alternator on Yanmar 30HP diesel 120AMP output

House Bank #2 which has 2 x 100AH Lithium (200AH)

which gets charged by...

2 100W Sunpower Solar Panels to Victron MPPT 100/30 controller whired directly to Lithium Batteries wired in parallel

1 Victron Orion Smart DC to DC charger non isolated from Starter AGM when engine is running and switch set to #1


System includes:

Victron SmartShunt to monitor bank1 and 2.

Xantrex InverterCharger 2000w for AC and dock charging if required


Concern:

I have a Victron SmartSense attached to (only) 1 of the Lithium batteries.

Why? I thought that the network having access to the battery temperature would more efficiently charge the bank? IS THIS CORRECT?


I've recently been reading through threads on similar setups in this forum and realize I have limited knowledge about the efficacy of my installation.

I'm now wondering if I should add a 2nd SmartSense to the other Lithium battery worried that the MPPT might output too much voltage to the battery if it doesn't have temperature? IS THIS A VALID CONCERN?


I am in the process and trying to create a wiring diagram and tracing various wires which is more difficult than one would imagine. Any help greatly appreciated.

MPPT ControllersMPPT SmartSolarSmart Battery Sense
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1 Answer
Alexandra avatar image
Alexandra answered ·

@Robert Baker

For lithium, the smart battery sense is really there for low temperature cut off. One can assume if one battery is cold the other will be as well, if they are together physically in the install.

Do you have much voltage drop from the charge sources to the MPPTs?

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Robert Baker avatar image Robert Baker commented ·
Thanks for your reply. I think the voltage drop is minimal.


I had thought there would be some use to the MPPT software to know what the temperature is and maybe be able to boost the voltage when the temperature is relatively low. But from your answer - this is not correct?


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