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| Author | Message | 
| groingo Member
 | # Posted: 17 May 2014 02:37pm - Edited by: groingo Reply
 
 Checking my charger and was curious how long it should take to add 5.00  amps to a 12 volt battery at 10 amp charge rate?
 I came up with 1.002975 hours.
 Next step is to verify and if works it could mean a much smaller solar system may fill the bill.
 
 
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| Flying Wrench Member
 | # Posted: 18 May 2014 10:05pm Reply
 
 What is the capacity of your battery? Also, keep in mind that charging your battery won't be 100% efficient.
 
 
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| groingo Member
 | # Posted: 18 May 2014 11:03pm - Edited by: groingo Reply
 
 Interstate battery was where I got the formula, tomorrow with a new set of batteries I will begin to verify if what they say is correct, my number also included a 15% variance on the high side....we'll see.
 
 
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| creeky Member
 | # Posted: 19 May 2014 11:46am Reply
 
 Looking forward to your results. I would have thought around 45 minutes... figuring the charging process to be 35% inefficient.
 
 
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| groingo Member
 | # Posted: 19 May 2014 12:55pm Reply
 
 Well, I decided to go with the 235 amp hour Trojan batteries which will be here in a couple of days, gives me time get things ready.
 As far as charge requirements that's also why I decided to go with the Trojans, just a better all round battery than the less expensive Empires, soon we shall see what is really what once and for all.
 
 
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| creeky Member
 | # Posted: 19 May 2014 01:23pm Reply
 
 cool. How many batteries?
 
 
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| groingo Member
 | # Posted: 19 May 2014 02:47pm Reply
 
 Just  two 6 volt 235 ah.
 
 
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| MtnDon Member
 | # Posted: 19 May 2014 07:46pm Reply
 
 Run some tests using a good hydrometer to determine charge state before being charged and to tell when the battery is really full. Better than voltage readings. Keep a log of the cells over time. Helps find problems.
 
 
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| groingo Member
 | # Posted: 19 May 2014 09:55pm - Edited by: groingo Reply
 
 Funny you brought that up, Interstate suggested the same thing so I got one yesterday.
 Crown battery also wants information when I get it, they agree with the numbers so this might get interesting, it will sure help simplify things to be sure.
 
 
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| MtnDon Member
 | # Posted: 19 May 2014 10:34pm Reply
 
 I am a big believer in logging data. I have gone as far as photographing the cells when new and more or less yearly after that.
 
 Does your hydrometer have a thermometer built in? Temperature correction is important if the battery temperature varies much seasonally. I have an old one with a thermometer I got at NAPA. But there's another I actually like better as the float is easier to read. I use a glass lab thermometer with it.
 
 
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