Recommendation for a 12volt accessory battery

2919 Views 16 Replies 8 Participants Last post by EVfun, Oct 13, 2010

corbin

Discussion Starter · Oct 10, 2010

Hi all,
I'm looking at replacing the big 12v accessory battery with a smaller motorcycle battery in my '69 bug conversion. I'll have a DC-DC converter to keep it topped off all the time, and I don't think the car will draw a lot of amps out of it (but, that is just a guess). Any recommendations for a battery? I was thinking of a little harley battery:

http://www.batterystuff.com/battery...++XL,+XLH+(Sportster)&theYear=1992&m=1#result

They are no maintenance and sealed.

thanks,
corbin

1 - 17 of 17 Posts

MN Driver

· #2 · Oct 10, 2010

It depends on if you are going for as lightweight as possible. Something as a 'just in case' the DC-DC kicks out. ...or the cheapest option possible.

My compromise is a lawn mower battery. Usually are rated in the high 200's for CCA which doesn't matter much since you won't need to use it but they have decent capacity and are not too heavy. ...best part, they are pretty much always under $30. You can pick up a flag to SAE terminal adapter set for a few bucks too if you are picky about connections. They normally come in a sealed maintenance-free flavor too. It all depends on what you are looking for though.

corbin

Discussion Starter · #3 · Oct 10, 2010

MN Driver said:
It depends on if you are going for as lightweight as possible. Something as a 'just in case' the DC-DC kicks out. ...or the cheapest option possible.

My compromise is a lawn mower battery. Usually are rated in the high 200's for CCA which doesn't matter much since you won't need to use it but they have decent capacity and are not too heavy. ...best part, they are pretty much always under $30. You can pick up a flag to SAE terminal adapter set for a few bucks too if you are picky about connections. They normally come in a sealed maintenance-free flavor too. It all depends on what you are looking for though.

Thanks -- I don't necessarily need cheap, I'm looking for something that will fit my needs yet lighter than the traditional battery. Specially, my needs are to run the accessory items in the car: headlights, various switches/contactors, heater blower fan, stereo, windshield wipers, etc -- all potentially at the same time. I'm sure I'm forgetting some things too.

My motorcycle needs a new battery, so I might just pick up two of the little harley batteries.

corbin

EVfun

· #4 · Oct 10, 2010

My preference for a 12v system battery is a Zappy scooter size battery. These are AGM batteries that are about 3.03 by 7.13 inches and 6.57 inches tall. The price is usually reasonable and it is a common size with a variety of uses. They are about 16 to 22 amp hours depending on the brand chosen.

corbin

Discussion Starter · #5 · Oct 10, 2010

EVfun said:
My preference for a 12v system battery is a Zappy scooter size battery. These are AGM batteries that are about 3.03 by 7.13 inches and 6.57 inches tall. The price is usually reasonable and it is a common size with a variety of uses. They are about 16 to 22 amp hours depending on the brand chosen.

Cool; I think I will go with one of those. I'm looking at a 12v 18Ah one for $45:

http://www.batterymart.com/p-12v-20ah-sealed-lead-acid-battery-2.html

or 21 ah for $55:

http://www.batterymart.com/p-12-volt-21-ah-sealed-lead-acid-battery.html#tabrev

I think I may go with the 18 Ah one. I don't expect the accessories to pull to much of a draw and the DC-DC converter should be able to keep up.

corbin

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rwaudio

· #6 · Oct 10, 2010

I'm using 12 headway 10ah cells in a 4s3p pack that will weigh just over 10 lbs but pack some pretty good power, it will be fed by an 80A dc/dc converter

RE Farmer

· #7 · Oct 11, 2010

corbin said:
Cool; I think I will go with one of those. I'm looking at a 12v 18Ah one for $45:

http://www.batterymart.com/p-12v-20ah-sealed-lead-acid-battery-2.html

or 21 ah for $55:

http://www.batterymart.com/p-12-volt-21-ah-sealed-lead-acid-battery.html#tabrev

I think I may go with the 18 Ah one. I don't expect the accessories to pull to much of a draw and the DC-DC converter should be able to keep up.

corbin

I don't recall seeing anything on your build blog about heat and defrost. Do you plan to go with electric heat? If so, it can draw quite a few amps.

corbin

Discussion Starter · #8 · Oct 12, 2010

RE Farmer said:
I don't recall seeing anything on your build blog about heat and defrost. Do you plan to go with electric heat? If so, it can draw quite a few amps.

Yes, I will be running a 1500 watt ceramic heater. I just ordered a kit from Canadian EV. Should I go with something bigger than 18 Ah? I still have yet to order something, as I discovered shipping for some of the batteries costs nearly as much as the battery. I might try to find a local source.

corbin

mcrickman

· #9 · Oct 12, 2010 (Edited)

I too am needing to get a accessory battery. I was a my local wal-mart and decided to take a look at batteries. I found two motorcycle batteries that seemed like a good size for my application. But after thinking about it I wasn't sure if they were 12v and not 6v. There was no voltage shown on the box ether.

So my question is whats the standard voltage for a motorcycle?

corbin

Discussion Starter · #10 · Oct 12, 2010

mcrickman said:
I too am needing to get a accessory battery. I was a my local wal-mart and decided to take a look at batteries. I found two motorcycle batteries that seemed like a good size for my application. But after thinking about it I wasn't sure if they were 12v and not 6v. There was no voltage shown on the box ether.

So my question is whats the stranded voltage for a motorcycle?

It might depend on the motorcycle, but 12v for the ones I've had.
corbin

DIYguy

· #11 · Oct 12, 2010

I would recommend this battery. It has 32Ah, it is a small utility AGM sealed unit. This is what I bought for my truck.
http://www.canadiantire.ca/AST/brow...%2BUtility%2BNo-Spill%2BBattery.jsp?locale=en

resago

· #12 · Oct 12, 2010

why use lead, why not 4 LiFePo4 cells??

or this:
http://www.batteryspace.com/customi...thpcbseparatechargeanddischargeterminals.aspx

mcrickman

· #13 · Oct 12, 2010

resago said:
why use lead, why not 4 LiFePo4 cells??

or this:
http://www.batteryspace.com/customi...thpcbseparatechargeanddischargeterminals.aspx

$300 bucks for an accessory battery? We only need the battery to turn on our DC/DC converter and to help with amp loads at times.

resago

· #14 · Oct 12, 2010

they DO have OTHER batteries.

http://www.batteryspace.com/lifepo418650battery128v4050mah5184wh7aratewpcb.aspx

corbin

Discussion Starter · #15 · Oct 13, 2010

resago said:
why use lead, why not 4 LiFePo4 cells??

or this:
http://www.batteryspace.com/customi...thpcbseparatechargeanddischargeterminals.aspx

I don't think you can directly hook up a DC-DC converter to the LifePO4 cells, right? It needs some type of smart charter to do it right. (Granted, I haven't gotten to the point of installing my converter yet... so I might be wrong).

But yea, $35 vs $350..

corbin

DIYguy

· #16 · Oct 13, 2010

resago said:
they DO have OTHER batteries.

http://www.batteryspace.com/lifepo418650battery128v4050mah5184wh7aratewpcb.aspx

4.5 Ah wont be enough ... you will need more, with heater + accessories....

EVfun

· #17 · Oct 13, 2010 (Edited)

corbin said:
Yes, I will be running a 1500 watt ceramic heater. I just ordered a kit from Canadian EV. Should I go with something bigger than 18 Ah? I still have yet to order something, as I discovered shipping for some of the batteries costs nearly as much as the battery. I might try to find a local source.

corbin

If you have a DC to DC converter to keep up with your 12 volt loads (or nearly keep up) you should be fine. The heater itself runs on the traction pack. The 12 volt system still has to run the heater fan.

An alternate 12 volt battery size that is very common and would make a good choice if your DC to DC is not large enough to keep up with demand would be the group U1 size (wheel chair size, many other uses.)

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