BAtteries, solar charges, regulators, Oh my

[Mike Whalen]

Greetings. Just purchased an 11 Watt solar battery charger. Since battery appeared to be really dead (after 12 hour trickle charge showed 5 volt reading) I also bought a new battery. I've read the 12 volt bible but have a couple of questions:1)Old battery was "trolling/RV" 160 amp. New one is "starter" 650 amp I assume this means that the new one has higher stroage capacity?2) Charger doesn't have a regulator. I hooked it up along with the new battery on Saturday. Then left the boat. NO WIND. On Sunday I went back out to put the panel inside for fear of cooking the new battery. The charger puts out about .62 peak as I understand it. I'm thinking about a second battery and looked at the switches available. Any thoughts on all in one units (regulator, multi-battery switch, charge indicator) They seem kinda pricey.3) to do multi chargers do I need the regulator designed to split off to multi-batteries. The actual set up of shuch things are not set out for solar in the 12 V. bible.Thanks,Mike

 

[Don Evans]

ahhhhhh....what you said...

Hi Mike. I have had a similar set-up for a few years and I'll try to answer some of your questons. You may have been correct in swapping out your old battery, but a trickle charger would have a hard time to bring back a drained deep cycle batt in 12 hours. These usually require a serious umph in charging (preferably through a 3 stage smart charger), especially if there really flat, but not knowing the history of this batt its difficult to say. Best bet, if you still have it, is to take it to a garage or batt store and have them do a "load test", to see if it can still take and hold a charge. It may very well be a dead batt, but you may be surprised and can still use it if it still has life? However what you have replaced it with is not a deep cycle but a starter battery. The 160A rating on the deep cycle is how deep cycles are rated (kinda like a fuel tank). The number of hours you draw from it and the load your drawing over those hours is your "mileage". The "new" batt, being a starter, is rated in CCA, or cold cranking amps and at 650 tells you very little about its capacity as a electron storage device but that it can deliver up to 650 A current for a 30 second period and maintain a specific voltage when the starter moter demands it (remember this is a starter batt and not a deep cycle). This however is not a deep cycle battery and should not be used for supplying house current over a long time period, as they will not stand up to being flattened repeatedly. Save this for the outboard and go and buy a "true" deep cycle. Your old batt was probably sized about right for your needs...depends though. Buy a 1,2 both switch, or a battery combiner and switches (see set up in West Marine catalogue) to go with the 2 batteries. I have 2- 1 A solar chargers (15W each) and a regulator. You won't need a regulator if you are only charging at .6A (it is probably even less than this) into a deep cycle of say about 180 A (however a 2 A regulator is pretty cheap). But it depends on the battery size as much as the charging output. I just use battery post clips on the end of my charger, and can put them on either house or starter batt, depending on which I want to charge. Hope some of this helps.Don

 

[Mike Whalen]

deep cell, deep trouble

Don,Thanks. I'd swear that the battery was marked deep cycle. But I ain't under oath. I called Wal-Mart where I bought it and they say yes it is deep cycle, they think. I don't have the ticket on me. I'll look at the battery. My concern was and is that if the battery is fully charged (and I don't use it much daysailing) can I cook it with the 11 watt charger? From what I read I'd think not but then they suppose more use than I put it to right now. I'll probably buy the switch an regulator to be safe. I'm on the cusp of building a box for the fuel tank in the cockpit. Still have all the lines aft gear in a box. Can't bring myself to work on those rare occasions when I can sail.Later,Mike

 

[Don Evans]

You Need To Know

I can't say, but if it is a "true" deep cycle, then they should be able to provide you with the amp hour rating. That value tells you more than any other rating. I know that Wall mart does sell deep cycle batts but they also sell hybrid batts too. That is ones that have a wee bit more lead in the plates than a starter (enought that they can call them deep cycle) but not a really a true deep cycle. It might be fine for your needs Mike having said all of that, especially if you only have minimal power requirements...say less than 50 amps over a days sail, but may not provide the life expectancy a true deep will give you. Again the number of times you flatten a battery, amoung other things, will dictate its life expectancy.I doubt you will cook a large capacity batt with only a .6 amp charger. After all thats theoretical maximum , and sun angle, clouds, shade will lower this even further. After all a smart charger lowers the amp input to about that level when the batts are topped up. Internal resistance and losses due to gassing and heat will prevent the batt from cooking at that charge level. I think though wall mart sells a 2 amp regulator for under 30 bucks if it will make you sleep better at night... 8^)Don

 

[Mike Whalen]

Thanks Don nm

nm