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mcwillem avatar image
mcwillem asked

Battery alarm when activate bowthruster?

I hope someone can help me. My set up is: MP2, with service lifepo4 accu bank, a starter battery 120ah LA for engine., and a LA battery for the bow thruster and one for the stern thruster the system. The last ones are on the output of the argofet connected with the energizer on D+

Ther is also a Orion TR Smart isolated running charger mode.

The Issue ; when engine runs in stationaire mode and I use one of the thrusters, i get a alarm from the starter battery on dashboard equipement, until the speed goes up.

Question ; can this be solved by the settings of Orion tr? Or maybe set on power feeding? Alternator is 55 amp Volvo engine marine boat . Al suggestions are welcome

orion-tr smartArgo FET Diodestarter battery
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offroadflow avatar image offroadflow commented ·
Maybe the battery is dying..?
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2 Answers
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pwfarnell answered ·

What is probably happening is that when the thruster is operated with the engine at low speed the alternator is not producing much charge current so the thruster draws power from the starter battery reducing the voltage. As the engine speeds up the alternator produces more power and the voltage recovers. As noted above, if the engine battery is not as good the voltage drop will be higher. On my boat the wiring from the starter battery to the bow thruster has been sized so that when the bow thruster operates only 45 or 50 amps flows to the thruster battery and most of the thruster demand of 300A comes from the thruster battery. But then there is 15m of cable between them. If there is a short heavy duty cable between the starter and thruster then the starter battery will be sharing the load. The other option would be a voltage sensitive relay between the batteries which disconnects the thruster battery on low voltage.

I can not comment on the Orion settings as you do not provide much detail, is this charging only the lithium battery. You might be able to set low voltage cut out to reduce load on the alternator when the thruster is running.

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mcwillem avatar image mcwillem commented ·

I think I have found the cause! Some alternators already have voltage on the B+, which means that the energizer does not have to be connected to it.

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mcwillem answered ·

Wauw, thnx for reply. All wires from starter battery and thrusters battery, approximately 5mtr using 16mm2. my previous installatie has two diode, now I am using 3x100 amp, argo FET, maybe this play a role for this issue. I'll think your suggestion to add an " voltage sensitive relay" are the best. It's correct when engine speeds up no problem at all.

Orion settings are simple.

Lifepo4 lithium accu bank ; ABS13,8, FLT 13,2 [ advise PurAccel]
Startbattery; input V lock; on 11.9 / out 12,5
Alternator; normal


I'll keep you inform. regards.

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