Date: Sun, 30 Dec 2018 15:19:08 -0800
Reply-To: Todd P Last <Rubatoguy@COMCAST.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Todd P Last <Rubatoguy@COMCAST.NET>
Subject: Re: House battery
In-Reply-To: <BN6PR22MB0723EF48CF4E2CE112D12B52A6B10@BN6PR22MB0723.namprd22.prod.outlook.com>
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<font face="Century Gothic">You might find some info here:<br>
<a class="moz-txt-link-freetext" href="https://batteryguy.com/kb/knowledge-base/connecting-batteries-in-parallel/">https://batteryguy.com/kb/knowledge-base/connecting-batteries-in-parallel/</a><br>
<br>
Also note:<br>
<a class="moz-txt-link-freetext" href="https://www.batterystuff.com/kb/articles/battery-articles/battery-bank-tutorial.html">https://www.batterystuff.com/kb/articles/battery-articles/battery-bank-tutorial.html</a><br>
<b>"</b></font><font face="Century Gothic"><b>the preferred method
for keeping the batteries equalized is to connect to the
positive at one end of the battery pack, and the negative at the
other end of the pack."</b><br>
<br>
If you have multiple batteries connected in parallel, and one
battery for whatever reason has a voltage drop of less than the
others, the other batteries will try to charge the battery with
the lower voltage. (an example would be if one of the batteries
has a dead cell.)<br>
I would think that if that is the case, the battery with the low
voltage will probably get hot over time.<br>
<br>
Todd<br>
'88 Westy<br>
<br>
</font><br>
<div class="moz-cite-prefix">On 12/30/2018 11:27 AM, Richard Smith
wrote:<br>
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cite="mid:BN6PR22MB0723EF48CF4E2CE112D12B52A6B10@BN6PR22MB0723.namprd22.prod.outlook.com">
<pre class="moz-quote-pre" wrap="">I have this setup, too, after reading a long detailed post from someone on the net. It sounded so cool.
I don't know if you have this scenario, but this is what happens to me:
Batteries are doing fine, slowly draining (I have a voltmeter on the dash so I can watch), and then "bam" they start to drain crazy fast. Just parked for a few hours (nothing but the clock radio connected) it will drop from 12v to 8v
My guess is that one cell in one of the batteries is defective. Once the overall battery drops below a certain level, all the other cells in all the other batteries start trying to level out and this causes the sudden/large drain. [I am no battery engineer, so this is just a guess.]
Because the two (in my case) UB1220s are wired together, it is hard to find out which one is causing the trouble. It didn't act like this right away, but I suspect if I took it apart I would find that one battery would be holding a charge and the other one would be 10 or 8 v (i.e., 1 or 2 cells dead).
It is winter here, and a nuisance time to struggle with batteries, so I'm going to leave it for now, but my sense is that the "multiple 1220" battery solution is not a good idea. I did another install like this, in my previous van, and had a failure there, too - the new owner ended up pulling the 3 1220s and putting in a regular type 41 battery.
It seems like a good idea - but in the end isn't worth it for the hassle/unreliability.
...r
On 2018-12-29, 3:20 PM, "Vanagon Mailing List on behalf of Jeremy Stovin" <a class="moz-txt-link-rfc2396E" href="mailto:vanagon@gerry.vanagon.comonbehalfofjjstov@YAHOO.COM"><vanagon@gerry.vanagon.com on behalf of jjstov@YAHOO.COM></a> wrote:
Hey all,
I’m sure I have thrown this out somewhere, but I cannot find it.
I love my ‘87 Westy, except for the issues I continue to have with my house battery.
I have done some upgrades that end up drawing a lot of power. I went through and found the draws. So, the biggest draws are the truckfridge and radio (got the switch so it won’t draw when not in use, but we like using it.)
I have a series of 3 wheelchair batteries under the driver’s seat, 12v, 66ah. But after a day and a half, without plugging in, it is dead. I had installed a portable 100w solar panel and controller, but I do not see that helped (that is another question for another day).
Bottom line: I want a battery with more Ah to last longer. Will even consider a lithium ion battery. The one, major constraint- I can only use a battery that will fit in that box under the driver’s seat. No room anywhere else. Seriously.
So, I am asking for suggestions and recommendations of batteries that will work.
(Seriously- do not recommend finding a different place for the battery. That will not help.)
Some other side details: have a battery charger/maintainer, a Yandina combiner and a victron monitor.
Thank for your feedback!
Jeremy
Sent from my iPad
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