Battery question - Honda RC51 Forum : RC51 Motorcycle Forums
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post #1 of 4 (permalink) Old 08-19-2014, 12:20 PM Thread Starter
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Battery question

I have an interesting question. I'm looking into replacing my RC51 battery, which needs to be replaced, and am considering the Shorai Lithium-Iron battery. Forgive my ignorance but if I can put this battery on my bike with no modifications to the electrical system, why do they want to also sell me a special Lithium battery charger? Is there any reason I can't continue to use my Battery Tender?

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post #2 of 4 (permalink) Old 08-19-2014, 01:18 PM
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A conventional tender left on for long periods will kill an Lipo4 battery, but unless you have an alarm or a parasitic drain you wont need to charge it anyway
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post #3 of 4 (permalink) Old 08-19-2014, 01:23 PM
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Try this:

(formatted to match Shorai's page)
Q. How do I maintain my Shorai LFX Battery?

LFX™ batteries should be recharged whenever voltage drops to 13.1 volts, or sooner. If you have a vintage, custom, or off-road vehicle which has NO draw on the battery when key is OFF, then you should only need to charge your LFX™ battery once a year. However, most modern street bikes have a draw even when key is off, to support clock, computer, alarms, or other devices. This draw will eventually drain the battery, which is damaging and could void your warranty. So if you are not riding twice a month, then you should charge the battery every few weeks. “Smart” lead-acid chargers with automatic cutoff may be used for periodic charging, but will NOT work as a tender/maintainer and should be disconnected immediately after charge has finished. Older lead chargers without automatic shut-off should never be used. Improper charging is dangerous and will void your warranty. A Shorai BMS Charger - with Store Mode - is highly recommended for anyone who rides less than twice a month. Alternatively, you may disconnect the negative cable from the battery for storage, and charge once per year in that case.

Q. Can I use Lead-Acid battery chargers or charger/tenders?

A. Yes. HOWEVER, you may NOT use a charger/tender if it has an automatic "desulfation mode", which cannot be turned off.

If you are storing your vehicle and want to check the remaining capacity, or you're a racer with a constant-loss system, you'll want to know how resting voltage (i.e. with no load or load under 200mA) maps to remaining capacity. LFX batteries should be maintained such that 20% capacity remains at minimum, as best practice. Use a good-quality voltmeter to check remaining capacity, and consider recharge whenever the battery capacity falls to about 50% remaining. Of course, if you get the Shorai dedicated BMS01 charger, you can just hit the "Store Mode" button and leave it to do the work for you.
Also, see this thread:

Last edited by extrapolator; 08-19-2014 at 01:32 PM.
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post #4 of 4 (permalink) Old 08-19-2014, 02:52 PM
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As linked, you are fine with the battery tender. I use it. Just use it as a charger and not as a maintainer (left plugged in after charging).
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