SLA back up battery recommendation

[jeohearn]

I need a back up set of batteries which I'd like to be SLAs. I recently had a bad experience with Universal Batteries (3x12v 8ah and 9ah sets) in that they clearly had been sitting on a shelf for a long time and so didn't last very long, or in one case, dead upon arrival. I am using them appropriately (discharging less than 50% etc). I was dealing with wholesalebatteriesdirect.com. They were good about sending me replacements and finally a full refund.
In this forum's Wiki, Universal Battery was recommended, but not a vendor. Can anyone recommend a source or vendor that might sell fresh ones? Or another brand that might be known to be fresh?

 

[dnmun]

gel batteries are kinda specific about the charging profile according to the battery maker. the gel is supposed to handle the deep discharge better from what i understand and the AGM delivers more power was their strong point.

is it possible you can force those SLA to recover by charging them differently? is lithium in your future?

 

[wesnewell]

Welcome to ES****Do this before your first post or now (it's retroactive)*****
Please go to the User Control Panel, select Profile, and then enter your city, state/province, and country into the Location field (country minimum) and save it. Once done, your location will appear in every post so you won't have people asking where you are ever again. This will help people help you. Example: Wylie, TX, USA. or just USA, but country as a minimum, and country is the most important. There are many cities with the same name all over the world. Without knowing what country you are in it's hard to make any recommendations. Thank you.
FWIW, I wouldn't recommend SLA batteries for any ebike. There are lots better options that aren't that much more expensive, and actually cheaper when you consider they last longer and give full capacity.

 

[dogman dan]

Joe has been around a long time, but I can't remember where he lives either. The cheapest supplier of a specific model of battery may not be the best, as you just learned.

It's all about freshness with batteries, especially lead. I'd look for the highest volume dealer of wheelchair batteries in your area, then, buy the size they sell the most. The 8 and 9 ah ones sell less than the 15 ah common on wheelchairs. But 12 ah is common for electric scooters, so maybe that size will be fresher.

 

[jeohearn]

If I go to a local shop to ensure 'freshness' then the price of 3 8ah SLAs is not worth it (3x$35). On the other hand $17x3 or even less (from one of those battery outlet websites) seems worth it to spend as a back up to my lithium pack...but no guarantee of freshness!
I'd be willing to spend $100 for some variation of lithium. All I need as a back up is 36v and 7 or 8 ah. 'Back up' meaning for emergencies or just to give my main pack a rest. I already have chargers for a LiFePO4 which is my main battery. I don't want the additional cost and hassle of a new charger to accommodate a new kind of battery.
Could someone point me to a source for this. I'm in Bay Area CA.

 

[dnmun]

what do you have to 'back up'? will this 36V battery be wired in parallel with the SLA?

 

[wesnewell]

8ah of 36v sla is 288wh with maybe 150 usable wh. A 5ah pack of 12s 44.4V rc lipo is 222 usable wh for $100 or less. 5ah of 10s 37V rc lipo is 185 usable wh for ~$80. If you just want to match the 8ah of sla, then 4ah of rc lipo will do that for ~$68.

 

[dogman dan]

$68 plus a charger. But as a reserve pack to be carried in an emergency, it's sure hard to beat a tiny RC lico pack. I have done that at times for years, for a ride just at the limit of the range for my pings.

I have a few spare chargers, if you need one extra cheap.

I seriously doubt a lead battery that sells for 17 bucks including shipping is going to perform good enough. Generally a good EV type would close to double that price.

 

[jeohearn]

Okay I'm in Bay area California. What/who is a good source for RC Lipo or other lithium battery pack? I'm not going to put anything together. I just want to buy a five plus amp hour pack that will work with my controller 36 volt. If I can get the charger pretty cheap then that sounds good.

 

[jeohearn]

Okay I'm in Bay area California. What/who is a good source for RC Lipo or other lithium battery pack? I'm not going to put anything together. I just want to buy a five plus amp hour pack that will work with my controller 36 volt. If I can get the charger pretty cheap then that sounds good.

 

[wesnewell]

Buy 2 of these. Plug the red of one into the black of the other. separate to parallel charge. Wait for the discount price to pop up in a few minutes before you buy.
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=15008
Buy a cheap 6s charger.

 

[dogman dan]

I agree.

 

[jeohearn]

Is the discount price for this about $41? This is the price it starts with. I'm not seeing the discount price pop up as you say. Do I need a 'discount code"?
Also, can I use the controller I already have? I got it from 'Dogman' and is a replacement that came with my Aetoma motor from about 5 years ago.

 

[wesnewell]

If you've been to the link before and seen the popup once, you won't see a discount popup again unless you clear your browsers cookies and history for the site. Discount is usually about 5-10%.

 

[jeohearn]

Is the discount price for this about $41? This is the price it starts with. I'm not seeing the discount price pop up as you say. Do I need a 'discount code"?
Also, can I use the controller I already have? I got it from 'Dogman' and is a replacement that came with my Aetoma motor from about 5 years ago.

 

[dogman dan]

12s lico will be about 50v fully charged, so that controller will work fine with it. You could run 14s with that controller if you wish, but 12s should work fine.

If you want to stay closer to 36v, then get two 5s packs, and run 10s. Assuming you do not have a voltage monitor, you will need one to run lipo. They can be as cheap as three bucks on ebay. Look for the one with only two wires.