A) How Long Would a Marine Battery Run an Electric Space Heater (obviously Size of Heater/battery Ma

When you look at the cost of the solar system you can hardly call the solar power "free". Most solar power systems have a very long payback and their performance begins to degrade as soon as the system is installed. Some case the lost of power production is much higher than the advertised information. If you want to use solar power to save money, then go for a solar hot water heating system. You will find it is a more economic deal.

1. What kind of Marine Battery should i get for my boat?

Any deep-cycle battery will work, though if there's a risk of knocking it over you should get a sealed one (the acid can eat holes in things). I am not sure the "marine" designation gets you more than a bigger price-tag. You might still be able to recover your old one as a spare. I went through all of mine with a dumb charger to get them over 2V and a smart charger with a desulphation cycle, and got 2 to the point where they are good for hours with a trolling motor, even if some cells are bad and it drops to 10V after 30 minutes.

2. What size marine battery do I need to power a 30lb thrust trolling motor ?

i have a 36 lb thrust and a 40 lb. i use a heavy duty deep cycle by wolverine. Im not sure if you would be able to find one because they are made locallly around my hometown of grand rapids. I paid $90 for mine. I absolutly love it. Minn-kota and optima also make great batteries but are quite expensive. I would say that an optima is the best ever

3. Is there such a thing as a 24 volt deep cycle marine battery? Is there a 36 volt?

24 Volt Marine Battery

4. Deep-cycle marine battery life question

When you parallel batteries, the combined reliability generally becomes less than the least reliable battery. In reliability engineering, this follows the equation:$$R_S=R_1*R_2*R_3 tag 1$$where $R_1, R_2,R_3$ is the reliability of the respective individual batteries.The older batteries are inherently more unreliable. Battery failure modes can cause the charging system to not properly charge the individual batteries and it can reduce the available energy when a load demand is asserted. The only failure mode that does not reduce the system reliability is a failure to an open condition. This is rarely seen on secondary batteries except when they contain integrated charge controllers, which is not the case for typical lead acid type batteries. To exemplify the formula, imagine that the new battery is 95% reliable and that the old batteries are 50% reliable. The combined reliability is 0.95*0.5*0.5 or 23.8% compared to 95% for the new battery alone.Aside from failures of the individual batteries, you may find that your charge controller is either not equipped to handle the combined charge current or it will not properly detect a charged condition of the combined batteries. If you wish to make your system redundant, at least from the battery perspective, you need to design the system to reliably charge each battery and also allow for each battery to independently supply the load regardless of the state of the other batteries. The reliabilty of a such a redundant system is:$$R_P=1-frac1frac1U_1frac1U_2frac1U_3 tag 2$$where $U_1, U_2, U_3$ is the respective unreliability of each battery. Unreliability is defined as 1 minus reliability. Using the same individual reliabilities from earlier, this would result in a combined battery reliability of 96% - not really worth the effort given the marginal improvement over the 95% reliability of the new battery.If you are relying on this battery system for any critical function, I would recommend against combining the batteries

5. What kind of bolts screw onto a deep cycle marine battery? My trolling motor cuts out because it's loose.?

tip: wingnuts, pliers. sounds like maybe your battery is not secured, and the vibrations of battery, wiring and boat are working together to loosen your wingnuts. Try a tie-down tray with a strap fastened to the deck or floor. Maybe just taping the wires to the battery case, so that the ring terminals are always moving in the same direction as the battery.