Peter, What is the chemistry of your existing batteries? Different chemistries and designs require different charging profiles. How do you plan to keep it charged? The means of charging has to be matched to the chemistry. Be careful in your selection of a battery since marine and AGM batteries in conventional automotive BCI group sizes are rarely true deep cycle batteries. Though, I suppose it could be argued that an anchor windlass could be more like a starting motor than a deep cycle load. You may find that a lithium battery fits this bill nicely. The ones used in commercial IT UPS solar arrays are available used and have their own charging control circuits. They don't require venting and can be oriented in any fashion. They are surprisingly light, have incredible discharge current, and can be charged comparatively much faster than almost any other tech. https://www.ebay.com/itm/Valence-U1-12RT-12v-Lithium-battery-packs-No-connector-Cords-Varied-Ah-/393130832481?_trksid=p2349624.m46890.l49292
If you decide to use lead acid or AGM then consider looking for ones with vent ports built right into the top of the case. These ports are designed to have a tube attached so as to vent the gasses to a fresh air location. Also remember that if your AGM is producing gas then it is also irreparably having its service life shortened since there is no way to replace the lost water. All of that being said, many people simply choose to use long over sized cables leading from the main house battery - I would. When doing an install like this, you would typically run the engine to help make up for the power usage. Well, running the engine during anchoring maneuvers is pretty typical anyway so that shouldn't really be an issue. Additionally, use a very high current relay located close to the battery to do the switching of the power for windlass ops. This keeps the risks associated with "always on" high amp conductors to a minimum since the positive wire would no longer be "always on". Using a solenoid/relay also saves the contacts in your windlass switches. Ugh! It could be ugly if a switch contact got welded shut in the raise position! Josh Muckley S/V Sea Hawk 1989 C&C 37+ Solomons, MD On Mon, Mar 15, 2021, 19:14 Peter McMinn via CnC-List <cnc-list@cnc-list.com> wrote: > Hey all, > > As I prepare to mount a new windlass on my ‘85 37, I intend to install a > new AGM 12v on the centerline just aft of the holding tank. There is plenty > of room here for a battery platform and accessibility is fair. I’ve done my > homework on voltage drop, cable size, etc. but if you have specific > experience on a 37 with a fwd-mounted battery, I’m mostly ears. > > My question relates to ventilation. The under-berth space is fairly large, > but I know AGMs need to gas and I don’t want to create a hazard. Any > suggestions for adding an adequate vent to this area? > Thanks to all of the subscribers that contributed to the list to help with > the costs involved. If you want to show your support to the list - use > PayPal to send contribution -- https://www.paypal.me/stumurray Thanks > - Stu
Thanks to all of the subscribers that contributed to the list to help with the costs involved. If you want to show your support to the list - use PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - Stu
