Deep cycle battery charger
Submitted: Tuesday, Apr 12, 2016 at 08:09
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Member - larsy
Hi everyone, needing advice, I am currently rebuilding my camper for some remote travelling.
I have currently 100a/h of batteries (3of Agm) in series that charge via solar. Questions are
Can I charge them with a normal battery charger I use on my car?
Thank you
Reply By: Athol W1 - Tuesday, Apr 12, 2016 at 08:36
Tuesday, Apr 12, 2016 at 08:36
Larsy
Are you sure that the batteries are in series, as this will give you a voltage that is the sum of all 3 batteries (ie 3 x 12 = 36 volts), whereas in parallel will only give the voltage of each of the batteries but the capacity of the 3 combined (ie 12 volts but 3 x 100 = 300ah).
Should your normal battery charger that you use for your car be a good quality multi stage charger of recent manufacture with the correct voltage output for the combination of the batteries then it would be suitable for charging AGM style batteries.
Hope this helps.
Athol
AnswerID:
598531
Reply By: Member - larsy - Tuesday, Apr 12, 2016 at 09:03
Tuesday, Apr 12, 2016 at 09:03
Hi,
Thanks for the quick replies!!
Sorry, they are parallel, yes are also charged via solar.
So a multistage charger, of 25amps would be suitable for backup?
I will go shopping and find a good one.
Any recommendations of decent brands to look for?
Thanks again.
AnswerID:
598536
Follow Up By: CSeaJay - Tuesday, Apr 12, 2016 at 10:31
Tuesday, Apr 12, 2016 at 10:31
Get yourself a CTek and forget about all your charging worries.
CJ
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Reply By: Sigmund - Tuesday, Apr 12, 2016 at 09:46
Tuesday, Apr 12, 2016 at 09:46
The advice I got on this is that the charger should be connected to one pole on the first battery and the other pole on the last.
Maybe I can jump in with a related question ....
I use a Powertech smart charger from Jaycar for bulk and float charging. When this is connected it defaults to a mode marked by a snowflake and the manual says this is recommended for two batteries in parallel which is in fact what's there.
However, in this mode it's putting in pulses of over 15v. My understanding is that this is high for AGMs. Would it be doing any damage?
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598540
Follow Up By: Nomadic Navara - Thursday, Apr 14, 2016 at 17:36
Thursday, Apr 14, 2016 at 17:36
What are these pulses you are referring to? If they are like those
described in this article then they will be beneficial.
FollowupID:
867831
Follow Up By: Sigmund - Thursday, Apr 14, 2016 at 17:58
Thursday, Apr 14, 2016 at 17:58
Thanks NN. I read that Rivers piece.
By pulses I mean this: when the charger is connected I'm looking at the voltmeter that's fitted to the CT, and it sits on c. 13.8 volts for about 10 seconds and then goes up to just over 15v for a second, drops back and repeats.
I've just hooked it up to get the times more accurately and it wouldn't do it!
So it according to Rivers it shouldn't be needed with AGMs. Question is whether it does damage.
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Follow Up By: Nomadic Navara - Thursday, Apr 14, 2016 at 22:32
Thursday, Apr 14, 2016 at 22:32
Sigmund, without knowing exactly the model number of your charger I can't assist you much. Please supply it.
"voltmeter that's fitted to the CT" What is this CT you are referring to?
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Follow Up By: Sigmund - Thursday, Apr 14, 2016 at 22:52
Thursday, Apr 14, 2016 at 22:52
CT = camper trailer Peter.
This is the charger model:
Click
Thanks.
FollowupID:
867843
Follow Up By: Nomadic Navara - Thursday, Apr 14, 2016 at 23:56
Thursday, Apr 14, 2016 at 23:56
Here are the details of a similar model of charger. Note the first stage of the charging:
"1. Diagnosis and Recovery - As soon as charging instruction is given to the charger, the unique diagnostic function automatically checks status of battery (detects voltage). If a deeply discharged battery's voltage is over 4.5 ± 0.10 (for 12V battery) or 16V±0.32V (for 24V battery), charger begins pulse charging with 5.0A high current and 1.5A low current to recover it, which terminates when voltage reaches to 10.5V±0.25V (for 12V battery) or 21V±0.42V (for 24V battery) at the beginning of the process, the charger skips pulse charging and it switches over to pre-selected charging mode. If within 7 hours voltage of battery does not rises to 10.5V±0.25V (for 12V battery) or 21V±0.42V (for 24V battery), charging process is terminated and battery is treated as bad battery."
I think you observed the first stage of charging. You have now brought the battery up to a charge level where the charger now slips through the first stage very quickly. That's why you are not seeing that pulsing first stage.
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Follow Up By: Sigmund - Friday, Apr 15, 2016 at 05:07
Friday, Apr 15, 2016 at 05:07
Thanks. Perhaps that's it.
The SoC was around 12.5 v when the charger was hooked up. (Analogue meter with 0.2 gradations). Will run it again and see if the pulsing is temporary.
FollowupID:
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