Best Power 2.5KVA UPS System Battery
OSI Batteries is your One Source for BestPower UPS System replacement batteries. 6FM33U1 is a high quality aftermarket battery that fits BestPower 2.5KVA model uninterruptible power supply systems.
BestPower 2.5KVA Requires 3 batteries per unit please add to cart accordingly.
We recommend checking your existing battery for size and specifications prior to ordering as manufacturers may change requirements without notice. The original batteries in many UPS Systems are tied together with wire harnesses and/or fuses; we recommend that you save these in order to reuse them with your replacement batteries.
BestPower 2.5KVA Requires 3 batteries per unit please add to cart accordingly.
We recommend checking your existing battery for size and specifications prior to ordering as manufacturers may change requirements without notice. The original batteries in many UPS Systems are tied together with wire harnesses and/or fuses; we recommend that you save these in order to reuse them with your replacement batteries.
| Chemistry: | Sealed Lead Acid |
| Nominal Voltage: | 12v |
| Nominal Capacity: | 33Ah |
| Dimensions (In.): | 7.68 x 5.12 x 6.10 |
| Terminals: | NB |
| Weight (lbs): | 22.5 |
| Warranty: | 12 months |
| Condition: | Brand New |
| Notes: | 10 Years Design Life |
Reviews
We're currently collecting product reviews for this item. In the meantime, here are some reviews from our past customers sharing their overall shopping experience.
4.7
Out of 5.0
Overall Rating
96%
of customers that buyfrom this merchant give
them a 4 or 5-Star rating.
October 20, 2026 by Jacob W. (TN, US)
“Very easy website to navigate and I appreciate that!”
Merchant Choice
Chat gpt recommended you for this older SL-20x stream light flashlight replacement battery.
Product choice
Price was really responsible, actually one of the cheapest I’ve seen not on eBay and in the US. Shopping for something and needing it in a reasonable time frame I always look for an address in the USA and I like supporting companies that still sell things like this in the state. Thank you for still supporting this flashlight!!
October 20, 2026 by Tom F. (CA, US)
“great service”
Merchant Choice
great price
October 19, 2026 by Jesse F. (NE, US)
“Very easy to find the item,”
