Printable View
I have two batteries, a cranking one and a trolling one. When I charge them I usually run jumper cables from one to the other and hook my charger up to one. I slow charge them on my 2 amp setting over night. It seems to work good and I don't have any problems but I didnt know if this might be bad for the battery itself. Thoughts or comments are appreciated. Thanks!!
Hi Snapper,
I am not a "pro" about batteries, but I don't think you will hurt anything like that. But I had a thought when I read your post I wanted to share......
If you are in a situation where you can buy and use regulary and an-board charger, it really is helpful and prolongs battery life very well. I've never done a "scientific study", but since I started (12 or so years ago) using a trickle charger all the time (constantly on when my boat is parked) I feel like I get about 50% longer battery life. From what I have read, the biggest benefit is that the trickle charger sends a tiny bit of current all, or almost all, the time to the batteries. This keeps the sulfates from building up on the lead plates -- this is what keeps the batteries good longer -- the plates stay clean and results in longer battery life and more powerful charge.
So if you are in a situation where you can use an on-board charger I think you'd find some real long-term benefits plus the peace of mind knowing the boat is always ready to go.
Jeff
I would suggest that you charge the batteries separately. Will the batteries charge that way? Probably to a point that they the charger says they are charged. Will it affect the life of the batteries? I would go with yes 90% of the time. The 10% is if you told me they were identical cranking\deep cycle batteries purchased at the same time. Even then, you are using the batteries in a different manner, thus they are discharging at a different rate. In almost every case of paralleling non-like batteries (of both style and age) is one battery will be weaker, thus adding strain to the better battery. In the case where one is a true cranking battery and one is a true deep cycle battery, the designs, purpose, and even charging needs are different. A cranking battery is designed to discharge quickly at higher rates and can (should?) be replenished in a faster\higher amped manner. A deep cycle battery is designed to discharge more slowly and over a longer period of time. These batteries should be replenished in a slower (trickle) manner. Most manual chargers have a switch for this. I would much more recommend you leave the batteries apart, charge the cranking battery on the cranking setting (which shouldn't take long) then charge the deep cycle battery on the deep cycle setting.