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Optimate Lithium 4S 5A Diagnostic Charger-Tester-Maintainer

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Part# 11-14676
MFR Model# TM-291


Ultimate LiFePO4 professional level battery charger.
High efficiency diagnostic charger and tester for LiFePO4 / LFP batteries. Perfect for charging and seasonal maintenance of a 12.8V-13.2V LiFePO4 / LFP battery sized from 2 to 100 Amp-hour.

Battery SAVE mode with BMS reset: starts from 0.5V with continuous monitoring/testing of charge acceptance or bad / shorted cell condition. Unnecessary (and unsafe) charging of a bad battery is prevented.

safeT: Automatic charge rate adjustment to ambient temperature sensed at the charger. Reduced charging below freezing, no charging if the temperature is below -20C/-4F (can damage lithium batteries).

Ampmatic: Microprocessor adjusts current to ideal LiFePO4 charge curve to match battery size/condition, for the fastest and most complete charge.

SAFE: No risk of overcharging. Totally safe for vehicle electronics. Sparks suppressed. Safe for long-term battery maintenance. Automatic shut-down if short-circuited or battery disconnected. 3-year limited replacement warranty.


  • CHARGING AMPS : 5A (AmpMatic)
  • USE : Indoor / Outdoor (lowest temperature: -4F / -20C).
  • SAVE : Low Volt Start of 0.5V + 3-step low volt SAVE and TEST.
  • IDEAL FOR : LiFePO4 (LFP) 4 series batteries from 2 100Ah.
  • INPUT : Global (100-240V 50-60Hz), high efficiency (CEC listed), fully sealed.
  • STYLE : Weatherproof case with wall mounts, with 6ft / 180cm AC supply lead and 6ft / 180cm charge lead ending in SAE connector. Weatherproof battery lead & standard battery clip set included.
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Easy to use charger. Does everything but bring a damaged battery back to new! Best price for this charger online!

Chris H
November 18, 2020


Please note, Aircraft Spruce's personnel are not certified aircraft mechanics and can only provide general support and ideas, which should not be relied upon or implemented in lieu of consulting an A&P or other qualified technician. Aircraft Spruce assumes no responsibility or liability for any issue or problem which may arise from any repair, modification or other work done from this knowledge base. Any product eligibility information provided here is based on general application guides and we recommend always referring to your specific aircraft parts manual, the parts manufacturer or consulting with a qualified mechanic.

Q: Is this model the same as TM-291?

Yes, this is Optimate model TM-291.

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