Larry,Larry DeMers wrote: Dan,
No, do not use a gel cell and a wet cell together, in any form, unless you for some reason have two separate chargers. You see, the top end voltage for a wet cell is different than that for a gel cell, and you r charger will try to obtain the highest voltage it can, based on it's design. This works so-so for wet cells, and not at all for gel cells.
What charger do you have, and is it a three stage charger? More than probably it is a ferro-resonant charger. If three stage, then the top voltage could be set for the gel cell, and then the wet cell would be undercharged. Or it could be set for the wet cell, and the gel cell will likely short out or be destroyed..possibly explode even (one of the warnings mentions this).
If the charger is a ferro-resonant charger, then only the wet cell will be mildly happy, as it takes a long time to get there with this charger, but it will eventually charge up to 14.6v or so, which exceeds the Do-Not-Exceed rating of the gel cells.
It's best to have a separate starting battery (typical truck starting battery..non-marine, and non-deep cycle) which is used ONLY for that purpose. Then add in a house bank..or two, as I have done. That bank should be sized to the boat, the load, the space available, charging source and type etc. This case would be a deep discharge cell..probably a group 27. They run around $45 every weekend at K-Mart. Realize that there is nothing magic about the "Marine" title when it comes to batteries..all you want are deep discharge cells. Separate these two banks with the 1-2-both-off switch, and then install a West Marine or Heart Interface Charge Combiner ahead of the two batteries, so that the charge is applied to both batteries until they become charged, then the combiner disconnects the two batteries from the charging buss. This runs around $140, and is the center of any charging system. All charge sources will be led through this device, be they solar, wind, thermalnuclear or "IT".
Cheers! and wondering how many figure out "IT"?
Larry DeMers
s/v DeLaMer
Cape Dory 30 ~~Lake Superior~~~
Dan H wrote: My CD25 came with two batteries. The original water filled type is currently installed. The former owner purchased a gel battery but did not install it. I would like to use both. The wiring is only set up for the one. Can I use two different types together? What wiring modifications are required to add the additional battery? If anyone can point me to "factory wiring scheme", I am thinking that might be best.
My charger is the alternator on the 1977 Johnson 9.9 outboard. Let me recap what I think you are saying. There is one set of cables coming from the motor. I lead those to the Charge Combiner unit, I then lead from the charge combiner to the Off-1-2-Both switch and on from there. When I want to start the motor, I set the switch to "1" because that is where the starter battery is. Once the engine is started, I flip the switch to "Both". The charge combiner has the intelligence to know what battery to charge and how much to charge it without blowing up me and the batteries. ?? I think I may have the switch and the combiner positions reversed??
This may explain why both my cars have electrical problems.
djhhan@aol.com