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Lithium Starter Battery

Hi,

I've received some equipment to upgrade my boats electrical system. However the company have sent me the wrong battery (100ah drop-in lithium) - should be 100ah Victron smart.

Anyway, they are going to do a swap out, but I was thinking if it would be possible to use it as my starter battery and maybe run a few other things from it - deck wash, nav lights...

My system will have 4x 100ah Victron Lithium batteries for the house bank. This is connected to a 12/3000/120 multiplus.

The solar MPPT and Alternator are connected to a 85ah agm battery and that connects to a cyrix li-ct in order to charge the house bank when charge is available.

What I'm thinking is to do the same with the MPPT, but run it through a Battery protect and have the ignition wire for the balmar external regulator also go through a small battery protect - both will be connected to the BMS charge disconnect that I have routed through my BMV 712 relay and set to disconnect at 14.2v.

Main concern is that currently when the Cyrix disconnects when solar charge is occurring the starter gets a quick dose of around 15volts before the MPPT reduces current.

Will the BP catch this quick enough in order to stop it getting to a lithium starter battery?

I don't think the same will occur with the alternator as once the regulator ignition wire goes out the stop off current should be instant, but say if you think I'm wrong.

Hope you can clear this up and maybe give alternatives I haven't thought of.

Thanks,

Michael


MPPT - Solar Charge ControllerBattery ProtectLithium battery Smartstarter battery
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Think I've found my answer. With regards to the BPs for the solar/regulator. That still seems like a workable option.

However the maximum continuous discharge rating for the battery is 100amps and the max pulse is 200A (<3S°C) , but not 100% sure what that means.

Anyway my engine has a 1.6Kw starter, so will take 133amps when cranking, so don't think the battery will handle it.

Feel free to comment, but think that could be then end of this plan :(

Michael

2 Answers
dazey77 avatar image
dazey77 answered ·

I have lithium batteries in both my motorbikes. They last a lot longer than lead acid! One bike has had the lipo for about 10 years and its still working. They work fine, and are a lot smaller and lighter. The only issue is that they don't much like the cold. If its cold out, you have to put a drain on them to get them a little warm and then start the engine. On my little one (alternator only lights), I turn the fan on, the big one turn the headlights on while I unlock it.

The self discharge is also basically nothing. The bikes have no alarms, can leave the a month and they are still charged. Be a few weeks with lead acid

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ejrossouw avatar image
ejrossouw answered ·

@stocksy There are some test on youtube where the capability of Lithium as starter batteries and it certainly can be used. The downside is that the battery won't last very long as unlike with LA, heavy discharge is not something they like. So, it can be done, but it is not ideal.

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Thanks will take a look. Also noticed that the charge current is on 20A on the battery, so definitely not going to work. Will stick to what I have as a starter and maybe get a larger one that can do lights, water pumps etc...