Super - Ultra Capacitors For Engine Starting

[DCMY #92]

I need to replace both port and starboard 8D starting batteries. I'm considering installing an ultra capacitor system with a group 31 battery to start both engines.

Does anyone have experience with the Maxwell, KBI, or other ultra capacitor system?

 

[Boatsb]

How long to restart after a failed attempt? Ho long until you bv can fire up an engine in an emergency if you lose it and cant immediately restart it?

I'd not look at it as a replacement for a marine engine. Maybe something on land.

 

[Scarlett]

Pm me if you want, I had a Maxwell on my last boat, maybe the best thing I have ever had on a boat. Mine was about the size of a group 32 battery and I was able to get rid of 2 8D’s and a group 24 battery. Was able to start 2 300 hp diesels and an 8 kwgenerator easily. The test they do on them is to start a 600 hp diesel at minus 40 degrees 3 times. The internal charger will recharge the capacitor in about 10 minutes with 10 volts. Amazing piece of equipment unfortunately not made in 32 volts or I would have one on my Hatt. John

 

[Westfield 11]

Pm me if you want, I had a Maxwell on my last boat, maybe the best thing I have ever had on a boat. Mine was about the size of a group 32 battery and I was able to get rid of 2 8D’s and a group 24 battery. Was able to start 2 300 hp diesels and an 8 kwgenerator easily. The test they do on them is to start a 600 hp diesel at minus 40 degrees 3 times. The internal charger will recharge the capacitor in about 10 minutes with 10 volts. Amazing piece of equipment unfortunately not made in 32 volts or I would have one on my Hatt. John

Unless your boat has it’s original starters you have 24v units. I’ve been told that replacement 32v units haven’t been available since well before the turn of the century. I know mine are 24v and have been for a very long time: long before I bought her. It’s a very intermittent cycle motor, not continuous duty.

 

[krush]

Pm me if you want, I had a Maxwell on my last boat, maybe the best thing I have ever had on a boat............... The internal charger will recharge the capacitor in about 10 minutes with 10 volts. Amazing piece of equipment unfortunately not made in 32 volts or I would have one on my Hatt. John

I did some research on these and saw that truck fleets had good reviews. I'm glad to hear real world boat experience. I'm not happy Maxell got bought by Tesla, but that's just a grumpy old man reason. https://www.maxwell.com/

I'm ditching my 8ds and going with something else. I was pondering the Maxell, but they were $800 a piece I think? I want one for each engine (cummins 8.3). I guess they last a long time, but batteries are $100 +/-a pop (2 per engine) Group 31 or 34.

 

[jim rosenthal]

I fyou have the original Hatteras cases, for 8Ds, three Gr 24s will fit right in there, sideways. Perfect fit. I use to in parallel to fire the engines, and the third one the generator.

Incidentally I think I got 11 years on the previous set of Deka Marine starting batteries...

 

[Boatsb]

Cummins did a great job lowering the needed amps for starting. A single grp 31 can spin the 5.9, 6.7 and 8.3 engines but 2 are always better.

Ive sold a bunch of the super duper starting agm batteries (low resistance and high cca) for starting but theres not a good solution in that technology for house banks.

 

[krush]

I fyou have the original Hatteras cases, for 8Ds, three Gr 24s will fit right in there, sideways. Perfect fit. ........

I have 3 plastic (with top) 8d battery boxes. I can't remember the brand. They are not original Hatt fiberglass. I will have to measure and see if G24 will fit sideways (but I do like the idea). Eventually I may move the battery location to outboard each engine, now that I'm not using 8d's.

My RV is an 8.3 and uses two group 34's. I couldn't fit g31 (better battery) in the holding tray.

 

[jim rosenthal]

I bet they will fit. The Hatteras cases fit a standard 8D. Let us know. I am happy with my multiple Gr24 rig.

 

[DCMY #92]

I've decided to replace the two 8Ds with two paralleled Deka Group 31 AGMs (800 CCA, 105 20 Ah Cap) and a KBI super capacitor. This setup will be used to start both engines.

KBI is more expensive than Maxwell, but has a higher max ambient temperature rating so less chance of high engine room temperature causing a problem. More importantly, it recharges in a couple of minutes instead of the Maxwell's 15 to 20 minutes.

I've been told that Tesla has eliminated Maxwell's super capacitor line. Don't know if that's true.

 

[krush]

Any long-term feedback on the KBI or Maxwell capacitors? I'm on decision time to buy new batteries or go for broke with new tech.

 

[Boatsb]

I've installed the northstar pure lead and the odyssey super cranking pure lead batteries on a few customers boats.

They are great for a burst to start engines. I'd bet a pair of grp 31 batteries from either (odyssey's owns northstar) will meet your needs. The cummins doesn't need huge bursts like the old detroits.

As for the caps I'd be wondering what will happen when you need to fire up an engine and theres a 3 minute recharge time.

 

[krush]

Maybe I will just build my own like this guy:

https://www.youtube.com/watch?v=GPJao1xLe7w


edit: and this guy improved on the design
https://www.youtube.com/watch?v=yWryYZFRot8

 

[Lmcruiser]

krush, I have a 1988 Viking 44 MY which original specs called for 2 8Ds in a box in engine room bilge. PO switched to 2 banks of 3 group 31 batteries. They fit sideways in the original box. I have 12 volt system and with 3 batteries paralleled I get more ah than 8D and a lot easier to get in and out. Had to change both banks last summer. The previous batteries were not special and lasted about 7 years.

 

[davidwigler]

Great idea! Let us know how it works.

 

[Boatsb]

The ECM may not like them. If the ECMs not happy nobody goes boating

 

[krush]

LMcruiser, your battery boxes must be wide. My boxes are from Todd (http://www.toddusa.com/battery-boxes.aspx) and and 21.5" x 11.5"


(all in inches LxWxH)
8d: 20 3/4 11 1/8 9 7/8
g31: 13 6 13/18 9 7/16

Group 24 and 34 will fit sideways
g24: 10 1/4 6 13/16 8 7/8
g34: 10 1/4 6 13/16 7 7/8

Did a lot of research and digging and my plan is now to go with one 24/34 per engine and build a capacitor deal...the Maxwell internal parts are easily available and it's a super simple device. It can be connected in parallel with the battery (I presume, like the maxwell generator power unit), or it can be used with a DC-DC converter to charge it to ~15 volts like the maxwell engine starting unit.

 

[Lmcruiser]

Boxes are probably custom built standard by Viking. I did not think about there being a difference in the boxes. Fortunately the PO had already made the conversion to the Group 31 batteries. Good luck with your project. Sounds like you have it engineered to work for your boat.

 

[spartonboat1]

I did some research on these and saw that truck fleets had good reviews. I'm glad to hear real world boat experience. I'm not happy Maxell got bought by Tesla, but that's just a grumpy old man reason. https://www.maxwell.com/

I'm ditching my 8ds and going with something else. I was pondering the Maxell, but they were $800 a piece I think? I want one for each engine (cummins 8.3). I guess they last a long time, but batteries are $100 +/-a pop (2 per engine) Group 31 or 34.

When you have $4.5Bn of the taxpayers money to play with and no requirement to pay it back, you can afford to buy stuff. Just sayin...

 

[krush]

To give an update to this thread, I haven't installed or sourced capacitors yet, but I did more research. I plan to put capacitors in parallel with a G31 battery. One set of G31 and capacitors for each engine. The capcaitors can be charged to 15V and connected directly to the starter, but I don't feel like doing this and it is unnecessary (read below).

I replaced the original starters on my cummins 8.3 with new designed gear reduction delco units: Delco Remy 39Mt 12V Starter - 8200433
https://www.jittruckparts.com/delco-remy-delco-remy-39mt-12v-starter-8200433

The original was a 38 size and I upgraded to the 39MT which is for engines up to 15liters. The physcial size of the starter was about the same. Around $340 each (memorial day 10% sale), brand new, official delco (now made in mexico instead of USA).

Original starters would draw over 1000 amps (my clamp meter only goes to 1000). New starters peak around 600-700 and crank the engine with no effort using one G31 battery. I replaced an 8d with one g31 and a newer starter and life is better.