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Lithium battery on an old motor

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Wdinse12

New member
I’m brand new here, I have a 1984 mercury 150 and wanted to run a LiTime lithium 12V 100ah dual purpose battery as my starting battery while still charging via the stator. From what I’ve found I need a regulator that’s around $245. I’m willing to buy it I just want some guidance on if it’s the right idea.
 
How much is teh battery? Add that cost to the regulator and decide if it's worth spending that much on an old motor. Do you need to replace batteries frequently?
 
I would think that a 1984 Mercury 150 would have come with a regulated voltage alternator installed. Are you saying that your motor does not have the means to charge a battery or is the battery being charged by unregulated voltage?

There are non OEM voltage regulators that can be obtained for well under $245.00.
 
The motor does charge the battery but the voltage at peak is around 16.8 which is much to high for a lithium. From what I know there is no regulator and it uses a stator.
 
racerone said:
Why introduce a possible fire hazard on a boat ?-----No lithium battery on my boat.
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I am almost old enough to remember when batteries in boats were considered dangerous.

Times change. Too many lithium batteries being used today with nil ill effects to consider them dangerous.

Mercury Marine has approved their use on a number of various Mercury models using different alternator types. I doubt such approval would have been issued if Mercury thought them to be dangerous.
 
I would be concerned about the charging current & voltage of that old technology engine being clean enough (as in true clean DC) & regulated close enough to not ruin those batteries.
Old fashioned lead acid battery was much more forgiving.
 
Droid said:
I would be concerned about the charging current & voltage of that old technology engine being clean enough (as in true clean DC) & regulated close enough to not ruin those batteries.
Old fashioned lead acid battery was much more forgiving.
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Droid is correct. Pb/acid can take some abuse, I have $$ LiPo4 in my RV, they use a different controller.
A thermal runaway on a NiCad or lithium…be prepared to swim.
 
A new voltage regulator should be more than adequate to charge a lithium battery. Easy enough to test the voltage output to see if it meets the battery suppliers specifications.

If the voltage is within specifications then no harm should befall the battery.
 
boscoe said:
A new voltage regulator should be more than adequate to charge a lithium battery. Easy enough to test the voltage output to see if it meets the battery suppliers specifications.

If the voltage is within specifications then no harm should befall the battery.
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This was my exact thought
 
That is the right track, I was thinking of using car chargers, which may have a desulfate f
function, which puts high voltage in.
LiFePo4 12V generally specify 12.2 to 12.6V for charging. If your supplies within that range, you should be fine.
One caveat is they really do not like to be charged below 0C. The better LiPos have a built-in BMS, which takes care of most of those issues.
 
Edchris177 said:
That is the right track, I was thinking of using car chargers, which may have a desulfate f
function, which puts high voltage in.
LiFePo4 12V generally specify 12.2 to 12.6V for charging. If your supplies within that range, you should be fine.
One caveat is they really do not like to be charged below 0C. The better LiPos have a built-in BMS, which takes care of most of those issues.
Click to expand...
Resting voltage for a lithium LiFePo4 is above 12.6 volts.

Suggested charge voltages for the OP's intended battery are shown below.

 
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