Review on KBi Kompact
Hello readers, today I’m sharing a first-hand review of a product designed to support boats with higher-than-usual electrical needs: the KBI Kompact supercapacitor. The Kompact acts as an auxiliary power source alongside traditional cranking batteries, drawing power from them or from the engine’s charging system. It’s also engineered to supplement lithium battery engine cranking limitations.
The KBi KSM Kompact gives you peace of mind on the water or the road, whenever you need to start up your engine and might need to deal with a dead battery. This device is the ideal backup system for traditional lead-acid batteries, because it’s always ready to help start your engine. KBi has also told us from their experiences that the Kompact usually outlives the boat it is installed in and needs little to no maintenance.
The KBi compact is yet another great product that we stand behind and believe will help many people who are left without power due to a dead battery. We hope you will be sure to check out all the other products from KBi.
KBi has been at the forefront of developing engine starting solutions since the company was established in 1969. We began with high-pressure starting fluid (ether) injection systems for diesel engines, and we created our first supercapacitor systems in 1996. Over the years, we have become a leader in engineering and manufacturing engine starting devices for boats, buses, RVs, heavy equipment, and more. KBi has a reputation for building effective, reliable products, and we have qualified for several OEM manufacturing Quality Standards.
Now, I will turn it over to Mike as he talks about his first-hand experience in installing the KBI compact on his boat and how it has benefited him.
My name is Mike owner of SV Delphine and I wanted to share with you an in-depth review of the modification I have made to my Catalina 387, built in 2005. I purchased the boat last year (2024) and realized that the flooded lead acid house battery bank was due to be replaced. Given the current technology, moving to lithium iron would be the prudent thing to do to maximize energy on board, especially giving the very limited available battery compartment space.
Converting from lead acid to lithium batteries was an important part of the motivation to install the KBI Kompact supercapacitor. I replaced the 2 original 4D 's with a single LiFePO EPOCH 300Ahr battery that had a maximum output current of 200 A (BMS Limit). The limited battery output current of the single EPOCH battery is due to the Battery Management System (BMS) semiconductor located inside the battery. This was below the npotential 250+ amps of draw current on the motor starter. The staff at e Marine Systems in Fort Lauderdale recommended the Kompact as a solution to this problem. The Kompact operates in parallel with the EPOCH,with the Kompact shunting most of the starting current away from the house battery bank all while maintaining a very firm voltage to the motor starter. The firm voltage available to the starter makes it operate with maximum power each and every time a start requirement is called upon.
Think of this like the time when a car new battery is installed, starting the engineresults in a nice quick solid crank from the starter. As the battery wears the softer cranking returns.This symptom is eliminated by having the Kompact installed which reflects an aggressive cranking every time the engine is started just like having a fresh battery!
Installation was not complicated at all. The Kompact replaced the space used by second 4D battery. I just transferred over the plus and minus power terminals to the Kompact.It did require connecting two small control lines to the starter accessory switch, but this was straight forward.
Weight savings was incredible. The original boat had (2) 4D batteries with a total weight of 270 lbs. This was replaced with an EPOCH 300 AHr, 12 Volt battery lithium ion iron that weighed 58 lbs., while the Kompact supercapacitor weighed only 8 lbs. (total 64 lbs. for both).Total weight savings was an incredible 206 lbs. Carrying a couple extra bottles of wine on board can now easily be justified.
Figure 1. Before install
Space savings came along as a bonus. The 4D battery measured 20.7”L x10.25”Wx 8.65”H (Fig 1) where as the Kompact is only 14.25”L x 10.25” W x 6.28”H (Fig 2),about a 40% saving in space ( 2 bottles of wine storage worth). The battery box cleaned up as well. Usable daily energy went from 180 ahr to 240 ahr yelding 30% increase.
Lifespan of product for return on investment is great, the Kompact unit costs $1578, but it's good for over1,000,000 cycles, meaning that it should never have to be replaced. A Group 27 starter battery costs approximately $425 plus installation and is typically good for five years. So within 15 years I've got a return on my investment, which for some may be longer than desired but keep in mind that the Kompact has “added value” to the vessel at the time of sale.
Figure 2. After Install
Best of all I can sail with confidence, and it is by far the best advantage I found to using Kompact. I do
not have to worry about being able to start my engine while at sea due to a dead or weak battery. Kompact stores an abundance of energy, and it allows it to be quickly dispersed during those few seconds when starting the engine has high demand requirements. In fact, if my lithium house battery were to give out, I could literally charge up the Kompact by utilizing my onboard solar panel and start my engine in an emergency. No battery could give me this kind of security!
In summary, I think I've uncovered one of the best kept technological secrets for cruising sailors. I highly recommend this product, you will not go wrong in making the switch, even if you're not moving away from AGM batteries.
Mike R
