Voltage surge startup

"I know this isn't exactly

"I know this isn't exactly a Crusader specific question, but one I'll bet others have experienced.

I get voltage drop <10V DC when starting port Crusader that restarts all my electronics - GPS, Sounder & Radar even with fully charged (bran-new) starting/deep cycle batteries (wet cells w/ 125AH rating) w/ battery selector switch in both position. Just bought the boat, so I am still working to figure out what devices draw from the port bank vs starboard (also 2 batteries), but believe it's only the 3 electronics mentioned. Even w/ radar off, GPS & sounder reset.
I plan this weekend to replace port battery connectors to increase contact area. Would running a separate + power wire from battery selector switch directly to electronics fuse panel help and be wise idea?"

"Thom; there are a number of

"Thom; there are a number of ways to solve this issue. So, you currently have 4 batteries, but none dedicated to the "house". In my boats, there are starting batteries for the engines and deep cycle batteries for everything else. Rather than continue to subject your electronics to starting surges and transients, consider a separate house battery. This also removes the chance of depleting a starting battery at anchor or drift.
Also, with gas motors, you don't really need two starting batteries per engine. Consider a single 1000MCA battery for each and a emergency start solenoid that connects port to stb batteries. This has worked well for my 454's for many years now."

"Thanks Dave, you know I was a

"Thanks Dave, you know I was afraid that this would be the advise. Yes, I have 4 batteries - 2 on each motor w/ traditional 1/2/both selector switches. The starboard bank actually has a deep-cycle only dry-cell as #2. I need to trace everything to learn the set-up first.

In the configuration you suggest, can/how could I charge the house batteries while at sea? I do a lot of drift/anchor fishing, so would need this capability. Also, I'd be concerned w/ running down house batteries from windless - real current hog. Doesn't that need to run directly from batteries?"

"Thom

the "house" a

"Thom

the "house" approach is the way to go. I'd suggest investigating ACRs - automatic charging relays...much more idiot proof than the existing switch (and better for the alternators, too).

Increasing the contact area of the connectors won't held if the wires they are connected to are too small (or too long).

The windlass instructions I've seen call for short, protected, direct connections. there's noting in the 'house' approach that would prohibit this."

"Wow, great info and help. Th

"Wow, great info and help. Thanks. I also found a long series of posts from 10/24/08 that goes into great detail on how to accomplish the house approach. As I'm thinking through, it doesn't seem all that complicated, will just take some time to trace and reconfigure.

On Windlass, I was just concerned with running down the house battery(s) prematurely, but normally have motors running when using anyway, so probably not an issue."

"Thom,

You mentioned chargi

"Thom,

You mentioned charging while at sea. You should see what type of alternators you have on your enigines. If they are the original OEM type then your alternators may not properly charge your batteries. I think you said you had wet cell dual pupose batteries on each motor. You should check with the battery manufacturer to see if your alternators can actually charge them effectively. Usually the voltage regulating part of standard alternators are good for wet cell starting batteries only. The more modern dual purpose wet cells, AGM, or gell cells may not get the proper charging, leading to improper charging levels and shortened battery life. If you plan to do a lot of the charging while at sea you might need to invest in a higher end alternator that has not only a higher output but much more refined charging controls built in for the these types of batteries. I have two Group 31 AGM deep cycle batteries in my boat. My standard alternators will not recharge them if they drop below a certain level. So I used the generator and the house chrager to charge them when I need to since my charger performs a precision three stage charging cycle specific for AGM batteries. Also the house charger takes into account temperature, another important factor, though the use of a probe mounted on the battery."

"Gregory,

Thanks for additi

"Gregory,

Thanks for additional info. Boat has OEM original Mando 55Amp alternators on both engs. The dual battery bank set-up does appear to be original with boat, and with all the elec accessories (many appear to be original equip), I can only assume that dual purpose batteries would have been required from get-go and alts would be designed appropriately to charge them. There has been many-many accessories added (elecs, etc) and suspect electrical system was not upgraded appropriately to support it all. I typically will only run the GPS & F/F while @anchor for safety.

I have used the boat a few times and do notice the expected slow & steady increase on voltage guage readings when running after prolonged drift/anchor, so assume batts are charging. I plan to check voltage readings coming directly off alternators & @batteries while running to confirm charging.

One thing I'm not comfortable with is the dry-cell arrangement on starboard side - see picture. I need to research mfg specs on dry-cell to assure it is being charged by alts. I do have an installed 20A shore power charger on boat, that this is wired only to #1 batteries on both sides. When charging from shore, I leave switch in both position to charge #2's as well, but understand this is probably not the best approach.

"

Thom:

You have some work ah

Thom:

You have some work ahead of you....mixed batery types within a bank will yield less than desired performance. Probably best attacked during the off season. That will give you plenty of time to research what you have and how to get your system "just right". OEM literature is a good start; just remember the marketing group usually gets to "edit" it. Calder and a few others have some well respected "how to" books out there. They provide a pretty broad coverage and make for good references.

"Agreed & do have some wor

"Agreed & do have some work in off-season. Short term, thinking I will just replace dry-cell with good wet-cell deep cycle. This should charge ok along with 3 other start/dc wet-cells-correct? Then I'll also run an emergency jumper w/ switch between the 2 banks for starting safety.

Can't thank everyone enough for all the input and experience sharing. Without it, think I was headed for long road of trial & error with emphasis on the error part. All the reading in the world can't supplant real life experience."

"Thom,

Look into the single

"Thom,

Look into the single most model of battery that you will ultimately decide to use everywhere as this will make your charging parameters the same for all batteries and provide for more stable performance from them"

And give you more flexibility

And give you more flexibility in the design of the 'new' system....redundancy is a great thing when you're 10 miles off the beach and REALLY great when you are 75 miles off.

"Yes, yup, yes and yup! <[img]

"Yes, yup, yes and yup! "

"Well put Mark,

Nice thing

"Well put Mark,

Nice thing about two of the same engines also...Maybe just to get 1 running, you have a complete inventory next door !"

"Well, didn't figure I&#39

"Well, didn't figure I'd bring this issue to a such a quick conclusion, but with all this input plus a little research, now have a plan that may partially fit into this season:

According to Deka site, all flooded L/A battery types - starting, D/C & dual purpose all charge similarly (ideally 14.1-14.4V), but at different rates..D/C fastest & starting slowest depending on amperage.

1. Create house bank-parallel both #2 cells via new battery switch.
2. House bank to consist of new L/A Deep cycle & 1 existing dual purpose (remove current D/C dry cell)
3. Leave both existing #1 L/A Dual battery in place as dedicated starter bank & run motors only in #1 battery position.
4. Wire house bank to existing DC accesory panel & install new small bus for electronics disconnecting both from main buss
5. Upgrade 1 of the alternators to higher output (80-100 amps w/ high idle output) and connect this to a new ACH that will service the house bank only. A real wake-up call in doing math to determine how long it takes to charge depleted house batteries from existing OEM alternators - 4x what I thought. Glad to learn this now rather than 50 miles out on night trip.
6. Leave starter batteries as is with direct alternator charging.
7. Connect existing 2-bank 20A shore power charger to both banks for full charging (need to explore this further.ie specs)

This set-up I think will give me a lot of flexibility - up to paralleling all 4 batteries together in emergency start scenario. Am I thinking everything through completely? I understand upgrading the alternator may not be simple matter - ie upgrading wires, etc."

"Thom,

Sounds good. Just t

"Thom,

Sounds good. Just two things to note. One, the new alternator will probably require new pully configuration since it takes more Hp from main enigne. I think these come with dual 1/2" pullies which you will need to match on the engine (PITA!). Two, I would use Mark's suggestion above and use an ACR with the engine starting batteries. The voltage regulator in the OEM alternator will not allow proper charging of the starting batteries IF you leave the battery selctor switch in the "All" or "Both" position. The regulator doesn't sense a significant voltage change when two batteries are parralelled and in turn no charge will take place. If you stay with your existing two battery switch you will have to make the switching yourself. Otherwise, have fun. Keep us posted on your results."

"Thanks. Alt change will have

"Thanks. Alt change will have to wait to off-season. Trop storm Danny coming up east coast will kill my fishing plans this weekend, but give me more time to work on boat, conditions permitting."

"update..only thing I got to d

"update..only thing I got to do this weekend due to rain Sat was check battery fluids (all full), voltage (all ~12.4 including dry-cell) and charge with my portable generator & charger (3 stage). My boat's house charger is not working - didnt' know this previously. The dry-cell (AGM)would not take any juice - charger said full. I know the AGM type batteries take a slightly higher voltage to charge completely and my charger is not designed for them. All 3 dual purp L/A on other hand took several hours of charge at 9-12 amps until ramping down to 1-2 amps at last stage. I suspect Gregory is correct in my alternators are probably not charging any of the batteries properly.

Got a reality check this weekend that I'm not going to have time to do any of the reconfig work discussed, so will resign myself to charging regularly w/ generator till off-season. Note after I charged both the port L/A Dual cells completely, I didn't experience that voltage surge that restarted electronics on port start. I did clean the battery cables and ran switch on both throughout day Sunday. I will reopen this discussion in off-season when I start the project."

Not a good idea to mix battery

Not a good idea to mix battery types being charged by the same charger. Had battery trouble myself all year--frustrating.

Jeff

Jeff-agreed on mixing types.in

Jeff-agreed on mixing types.inherited this arrangement. I will be replacing the dry-cell with a new L/A deep cycle. This should get me through rest of season-I hope- with no problems.

"Thom,

This is definitely t

"Thom,

This is definitely turning out to be a learning experience for you. Marine electrical systems can be complex and can be specialized for your purposes. Battery technology and charging systems add to that complexity. Learning is fun. Always have fun."